TotalEnergies ne « gagne » pas d’argent en France : le rôle des prix de cession interne

Source: The Conversation – France (in French) – By Benjamin Bournel, Maitre de conférences en Sciences de Gestion (spécialité comptabilité), Université de Poitiers

Alors que TotalEnergies a engrangé plus de 19 milliards de dollars de bénéfices en 2023, ses filiales françaises affichent des résultats bien plus modestes. Ce paradoxe est le produit d’un mécanisme méconnu du grand public, mais central dans la fiscalité des multinationales : les prix de cession interne. Comprendre ce dispositif, c’est aussi comprendre pourquoi les États peinent à taxer les grandes entreprises à la hauteur de leur puissance réelle. Une question que les débats autour d’un éventuel impôt sur les « surprofits » viennent relancer.


Note de l’auteur : cet article présente des structures d’entreprises et des mécanismes généraux comptables. Il ne vise en aucun cas à établir que TotalEnergies commet des irrégularités fiscales.

Imaginez une entreprise dirigée depuis la France, qui extrait du pétrole en Afrique, puis raffine en France et distribue dans toute l’Europe. On pourrait s’attendre à ce que cette entreprise paie une part importante de ses impôts en France, là où une grande partie de son activité se déroule. Pourtant la réalité n’est pas toujours là, et ce n’est pas (toujours) illégal.

Le mécanisme en cause s’appelle les prix de cession interne, ou prix de transfert. Il désigne les prix auxquels les différentes filiales d’un même groupe se facturent mutuellement des biens, des services ou des actifs. En apparence technique, ce dispositif est en réalité au cœur d’un enjeu politique et économique majeur : qui, au sein du groupe, paie l’impôt ? Combien paie chacune de ses entités ? Et où « choisit »-on de les payer ?




À lire aussi :
La transparence fiscale des entreprises commence dans les conseils d’administration


Constellation d’entreprises

Un groupe multinational comme TotalEnergies n’est pas une seule entreprise. C’est une constellation de plusieurs centaines de filiales, fonctionnant comme des entités à part entière, réparties dans des dizaines de pays, qui échangent en permanence entre elles. Ces échanges sont inévitables : le pétrole brut extrait par une filiale doit être ensuite vendu à celle qui le raffine, les technologies développées par une autre seront utilisées par d’autres et le tout, grâce à des financements circulant d’une entité à une autre.

Or, chaque fois que deux filiales d’un même groupe se facturent quelque chose, un prix doit être fixé. Et ce prix – le prix de cession interne – a une conséquence directe sur la localisation des profits du groupe : si une filiale vend très cher à une autre, elle l’enrichit comptablement à ses dépens. Et, qui dit profit, dit impôts sur les sociétés. Fixer les prix de transfert, c’est donc, en partie, choisir dans quel pays le groupe va payer ses impôts.

En théorie, ce choix est encadré. Les règles internationales établies par l’OCDE imposent que ces prix respectent le principe dit de « pleine concurrence » : les filiales d’un groupe doivent se facturer comme elles le feraient sur le marché, ou bien en fonction des prix pratiqués sur le marché par d’autres entreprises indépendantes. En pratique, l’application de ce principe est très complexe.

De l’Angola à la Normandie en passant par la Suisse

Prenons un exemple concret : un baril de pétrole brut est extrait par une filiale de TotalEnergies en Angola. Il doit ensuite être vendu à la filiale de raffinage, par exemple celle de Normandie. Cependant, entre les deux, les flux financiers passent par une société de trading, dont le siège se situe à Genève.

Pourquoi Genève ? La Suisse applique une fiscalité particulièrement favorable aux sociétés de négoce international. La filiale de trading achète donc le pétrole brut à bas prix à la filiale d’extraction, et le revend à prix plus élevé à la filiale de raffinage française. La marge commerciale – parfois substantielle – est ainsi captée en Suisse, où elle sera faiblement taxée, plutôt qu’en France ou en Angola.

Pour la filiale française, elle achète sa matière première à un prix élevé. Ses coûts de production sont alors plus importants, sa marge est comprimée et présente ainsi un résultat modeste, voire nul, et paie peu d’impôt sur les sociétés en France.

Le cas des actifs intangibles

Ce schéma n’est pas propre au marché du pétrole. Il se retrouve dans tous les secteurs où les multinationales opèrent : le numérique (avec les terres rares, ou les composants), la pharmacie (avec les brevets sur les médicaments) ou encore la grande distribution (avec les marques et enseignes ou les centrales d’achat).

Si les prix de transferts sur les biens physiques sont déjà difficiles à contrôler, le problème est encore plus important avec les actifs intangibles, qu’il s’agisse de brevets, de marques, de logiciels, de données, d’algorithmes… Ces actifs n’ont pas de prix de marché observable. Les multinationales ont donc toute latitude pour loger ces actifs dans des filiales situées dans des pays à faible fiscalité – Irlande, Luxembourg, Pays-Bas, etc. – et faire payer des redevances à toutes les autres filiales du groupe. Chaque redevance versée est une charge déductible pour la filiale qui la paie (réduisant ainsi le bénéfice imposable), et un revenu pour la filiale qui la reçoit (plus faiblement taxé).

Des milliards de manque à gagner

L’économiste Gabriel Zucman, professeur à l’École d’économie de Paris, a récemment estimé que 40 % des profits des multinationales mondiales sont artificiellement déplacés vers des pays à fiscalité réduite, représentant plusieurs milliards de manques à gagner pour les états.

Face à ces pratiques, les États ne restent pas inactifs. En France, l’administration fiscale peut contrôler les prix de cession interne des entreprises et les requalifier si elle estime qu’ils ne respectent pas le principe de pleine concurrence. Mais ce contrôle se heurte à une réalité pointée par la Cour des comptes dans son rapport sur le contrôle fiscal des grandes entreprises : l’administration fiscale rencontre des difficultés structurelles, notamment un manque de ressources humaines, pour faire face à la sophistication croissante de l’optimisation fiscale.

France 24 – 2026.

Au niveau international, deux grandes initiatives sont à relever. Le projet BEPS (Base Erosion and Profit Shifting) de l’OCDE, lancé en 2013, a produit une série de recommandations visant à mieux encadrer les prix de transfert et à obliger les multinationales à déclarer leurs profits par pays : le Country-by-Country Reporting. Ces déclarations, pays par pays, désormais obligatoires dans l’Union européenne, permettent aux administrations de mieux identifier les écarts suspects entre les pays où sont déclarés les profits et ceux où l’activité économique a réellement lieu.

Une solution : l’impôt mondial ?

Plus récemment, l’accord sur un impôt mondial minimum de 15 % sur les bénéfices des multinationales, conclu en 2021 et progressivement mis en œuvre au sein de l’UE depuis 2024, représente une avancée importante. En fixant un plancher fiscal universel, il réduit mécaniquement l’intérêt de déplacer des profits vers des pays aux fiscalités avantageuses.

Enfin, il est important de préciser qu’il serait inexact de présenter TotalEnergies – et de manière générale, toutes les multinationales recourant à cette pratique – comme des entreprises hors la loi, recourant à de l’évasion fiscale. Dans leur grande majorité, ces pratiques sont légales, encadrées par des règles que les entreprises respectent scrupuleusement. Le problème se situe davantage sur les règles elles-mêmes, insuffisantes, incomplètes et souvent interprétables.

Les prix de cession interne ne sont pas une anomalie du système : ils en sont un produit logique. Tant que les États fixeront des taux d’imposition différents et que les multinationales opéreront dans plusieurs juridictions, la tentation de déplacer des profits existera.

The Conversation

Benjamin Bournel ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d’une organisation qui pourrait tirer profit de cet article, et n’a déclaré aucune autre affiliation que son organisme de recherche.

ref. TotalEnergies ne « gagne » pas d’argent en France : le rôle des prix de cession interne – https://theconversation.com/totalenergies-ne-gagne-pas-dargent-en-france-le-role-des-prix-de-cession-interne-282105

Pesticides : mieux les évaluer pour mieux protéger notre santé et limiter la contamination de l’air, des eaux et des sols

Source: The Conversation – France in French (3) – By Cécile Chevrier, Epidemiologie, Inserm

Dans le cadre du paquet législatif « Omnibus X – Sécurité alimentaire et alimentation animale », la Commission européenne propose de simplifier les procédures d’autorisation de mise sur le marché des pesticides, alors que les données scientifiques montrent une contamination généralisée de la population mais aussi de l’air, des eaux et des sols. La décision de la Commission européenne irait à rebours du nécessaire renforcement de l’évaluation des pesticides afin de protéger la santé humaine et limiter la pollution de l’environnement.


Comment un pesticide est-il évalué et mis sur le marché ? Pourquoi les pesticides peuvent-ils présenter des risques pour la santé et l’environnement alors que leurs usages sont autorisés ? On fait le point.

Qu’est-ce qu’un pesticide ?

Un pesticide (pest- : nuisible ; -cide : tuer) est utilisé pour contrôler et/ou tuer les organismes vivants que nous considérons nuisibles pour nos activités, telles que l’agriculture, mais aussi la protection du bois, les transports, ou la lutte contre les moustiques.

Cependant, un pesticide peut présenter un risque pour des organismes a priori non ciblés s’il entre en contact avec eux. Par exemple, certains insecticides agissent sur l’insecte ciblé par des mécanismes de neurotoxicité communs à d’autres organismes, comme les abeilles ou l’espèce humaine. Être en contact avec un pesticide présente donc un risque potentiel qu’il faut pouvoir identifier et maîtriser.

Comment un pesticide est-il actuellement autorisé ?

Dans le langage réglementaire, les pesticides utilisés notamment sur les cultures pour notre agriculture sont appelés plus positivement : produits phytopharmaceutiques (pharmaco- pour médicaments ; phyto- pour plantes), c’est-à-dire produits de protection des plantes.

Un peu d’histoire… Nous utilisons des pesticides depuis des siècles. C’est en 1978 que l’Europe démarre un processus d’harmonisation avec une liste commune de produits interdits, prenant conscience du danger qu’ils peuvent représenter pour la santé humaine.

En 1991, s’opère un changement de paradigme important avec l’établissement d’une « liste positive » (en d’autres termes, tout produit-pesticide doit être autorisé avant d’être mis sur le marché), l’implication des industriels dans la preuve de l’innocuité des produits qu’ils commercialisent, et la considération de la protection de l’environnement (Directive 91/414/CEE du Conseil du 15 juillet 1991 concernant la mise sur le marché des produits phytopharmaceutiques)

Aujourd’hui, c’est le Règlement européen (CE) No 1107/2009 qui régit la mise sur le marché des produits phytopharmaceutiques. Cette évaluation des risques a priori impose une série de tests que l’industriel doit conduire pour évaluer les propriétés toxicologiques, environnementales et écotoxicologiques de la substance-pesticide qu’il souhaite introduire ou réintroduire sur le marché européen.

L’EFSA (Autorité européenne de sécurité sanitaire des aliments) évalue la conformité des tests réalisés par les industriels et de leurs résultats, et réalise l’évaluation des risques en vue de l’approbation (ou non) de la substance par la Commission européenne. Puis, pour le cas de la France, c’est l’Agence nationale de sécurité sanitaire de l’alimentation, de l’environnement et du travail (Anses) qui autorise (ou non) les produits commerciaux contenant cette substance et ses coformulants et qui définit des conditions d’usage possibles pour une bonne protection des utilisateurs et de l’environnement.

Finalement, selon les termes du règlement, l’autorisation est obtenue s’il n’y a « aucun effet nocif sur la santé humaine ou animale » (c’est-à-dire si les risques sont considérés comme « maîtrisés » avec notamment l’identification d’une dose sans effet), « ni aucun effet inacceptable sur l’environnement » (ce qui ne signifie pas qu’il n’y a pas d’effet).

En outre, « pour des raisons de sécurité » dixit le règlement, l’autorisation d’une substance ne peut qu’être limitée dans le temps (jusqu’à 15 ans maximum). La substance doit faire l’objet de réévaluations afin de prendre en compte l’évolution des lignes directrices des tests réglementaires ainsi que des connaissances scientifiques. Pour résumer, les substances doivent être réévaluées périodiquement et de façon de plus en plus complète.

Une évaluation réglementaire nécessaire mais incomplète

L’évaluation a priori est nécessaire car elle permet dans un cadre commun européen d’éviter la mise sur le marché de pesticides fortement nocifs pour la santé humaine et animale et/ou dangereux pour l’environnement. Toutefois, elle est insuffisante par construction, car elle ne teste pas les conditions réelles d’usage et d’exposition.

Prenons un exemple : de récents travaux montrent que la moitié des enfants français de 3,5 ans ont été en contact avec plus de 68 pesticides différents en seulement quelques mois (les résultats ont été obtenus par des mesures dans les cheveux). Or il n’existe pas de « tests réglementaires » ni de conditions de laboratoire qui permettent de reproduire cette exposition multiple et répétée et d’étudier les risques associés, à plus ou moins long terme, dans la vie de l’enfant.

Un autre exemple décrit la présence de pesticides en cours d’utilisation dans des zones très éloignées des traitements (au niveau du pôle Nord, en montagne, etc.), qui est révélatrice d’une persistance atmosphérique non anticipée par l’évaluation a priori actuelle, et potentiellement à risque pour ces écosystèmes lointains.

Le mode d’évaluation actuel des pesticides se révèle peu réactif face aux nouvelles connaissances scientifiques. Plus de dix années ont en effet été nécessaires pour que l’EFSA (Autorité européenne de sécurité sanitaire des aliments) publie, en 2023, la version finalisée du document-guide dédié à l’évaluation des risques pour les abeilles. Et celui-ci n’est toujours pas mis en application… alors que la science continue à avancer en parallèle.

Enfin, dans les faits, il est plus simple pour les autorités en charge de l’évaluation de la conformité des tests d’invalider des données scientifiques non conformes au cadre réglementaire que de remettre en question l’ensemble du processus d’évaluation des risques.

Des observations de contamination environnementale et risques associés aux pesticides qui s’accumulent

Une fois un pesticide mis sur le marché, il est essentiel de mettre en place des études pour surveiller a posteriori, en conditions réelles, à court, moyen et si possible long termes, les potentiels effets indésirables non identifiés a priori.

En France, les études de surveillance environnementale mettent en évidence depuis plusieurs décennies une contamination quasi généralisée de l’environnement, « en ville » comme « à la campagne » au niveau des eaux, des sols et de l’air. Cette surveillance est majoritairement issue d’initiatives d’acteurs associatifs et académiques et largement dépendante de financements publics. Un grand nombre de ces données est accessible en ligne.

Un large corpus d’autres études observationnelles issues de la recherche académique, conduites dans la population humaine ou animale, a permis de conclure à l’existence d’un risque pour la santé humaine, en particulier pour les utilisateurs des produits-pesticides et les enfants, et de risques pour la biodiversité et ses fonctions écosystémiques, pourtant elles-mêmes essentielles aux activités agricoles.




À lire aussi :
Pesticides et santé : les agriculteurs ont été, sont et seront les principales victimes de ces substances


On ne peut plus nier aujourd’hui que le système tel qu’il a été construit implique la présence de risques non maîtrisés pour la santé et pour les écosystèmes. Certains sont reconnus en France puisque ces connaissances scientifiques consolidées ont aidé aux systèmes de réparation des victimes professionnelles, à la sensibilisation des utilisateurs, des préventeurs (c’est-à-dire les professionnels de la prévention, ndlr).

Un système de vigilance vis-à-vis des risques des pesticides à consolider

Comme pour les médicaments, il existe en France un système de vigilance vis-à-vis des « effets indésirables » des pesticides observés a posteriori (c.-à-d., après leur mise sur le marché). Ce dispositif de phytopharmacovigilance (ou PPV), piloté par l’Anses, est unique en Europe, mais reste peu connu et insuffisamment encouragé. Sa mission initiale est d’identifier les effets indésirables pour faire évoluer les dossiers réglementaires à l’échelle nationale, en proposant des modifications aux autorisations des produits-pesticides.

Les données de surveillance environnementale et la littérature scientifique constituent des sources d’informations importantes. Un bilan des 10 ans d’activités de phytopharmacovigilance démontre l’utilité et le succès de ce système.

Par exemple :

  • une contamination inattendue de cultures non traitées par le prosulfocarbe, une substance active très employée en France en tant qu’herbicide, a conduit à durcir les conditions d’emploi (en l’occurrence, les traitements ont été interdits dans un rayon de 1 km de productions agricoles sensibles prêtes à être récoltées) ;

  • les situations de non-conformité des eaux (caractérisées par des taux supérieurs à un seuil de référence) ont conduit à des réductions de doses d’emploi autorisées du S-métolachlore, une autre substance herbicide ;

  • des situations nouvelles peuvent aussi constituer un signal à gérer, par exemple la mesure dans les eaux de l’acide trifluoroacétique, un composé appartenant à la famille des PFAS.

Cependant, ces signaux préoccupants pris en charge ne sont que l’« arbre qui cache la forêt ». De fait, ce dispositif de vigilance n’identifie pas comme signal la contamination des milieux ou l’exposition de la population générale, pourtant régulièrement observées, banalisant ainsi cette connaissance. L’absence de seuil de référence sanitaire, souvent difficile et long à déterminer, écarte aussi la possibilité d’un signal de vigilance. C’est notamment le cas de l’observation ubiquitaire de traces d’insecticides pyréthrinoïdes dans les urines de la population française depuis plus de 10 ans.

De plus, comme l’évaluation a priori, le système de vigilance actuel n’est pas conçu pour considérer la problématique d’une exposition à des mélanges. Ainsi, si l’on reprend l’exemple cité plus haut, la moitié des enfants français seront encore longtemps exposés à plus de 68 pesticides.

Enfin, une fois identifié, le signal est transmis aux acteurs décisionnaires. Mais sa gestion dépend de la compréhension et de la sensibilité de ces acteurs face à ces connaissances.

Une banalisation des contaminations environnementales et des expositions humaines préoccupante

Les connaissances montrent une complexité croissante des contaminations environnementales ainsi que des risques directs et indirects pour la santé humaine, animale et des écosystèmes. La banalisation de cette connaissance est préoccupante. Elle est devenue pour certains acteurs une normalité et engendre un risque croissant de régression des politiques publiques.

Une simplification des procédures d’évaluation a priori des risques des pesticides est ainsi à contresens du besoin. Il est illusoire de penser que les coûts économisés par cette simplification seraient supérieurs aux coûts des conséquences multiples et complexes sur la santé et l’environnement.

Au contraire, l’évolution continue à la lumière des nouvelles connaissances scientifiques et des nouvelles pratiques agricoles, de ces systèmes d’évaluation a priori et a posteriori des risques, ainsi que leur rapprochement, sont nécessaires pour préserver la santé de tous.


Ont contribué à la rédaction de cet article : Brice Appenzeller (Luxembourg Institute of Health, Luxembourg), Carole Bedos (UMR ECOSYS, Université Paris-Saclay, INRAE, AgroParisTech, Palaiseau, France), Rémi Béranger (UMR1085 Inserm, Université Rennes, Irset, Rennes, France), Aurélie Berthet (Centre universitaire de médecine générale et santé publique, Unisanté, Lausanne, Suisse), Cécile Chevrier (UMR1085 Inserm, Université Rennes, Irset, Rennes, France), Fleur Delva (U1219 Inserm, Université de Bordeaux, Bordeaux Population Health Center, ISPED, Bordeaux, France), Marc Gallien (ULR 4477, Université Littoral Côte d’Opale, Université Lille), Emmanuelle Kesse-Guyot (U1153 Inserm, U1125 INRAE, CNAM, Université Sorbonne Paris Nord, CRESS, Bobigny, France), Laure Mamy (UMR ECOSYS, Université Paris-Saclay, INRAE, AgroParisTech, Palaiseau, France), Christian Mougin (UMR ECOSYS, Université Paris-Saclay, INRAE, AgroParisTech, Palaiseau, France), Maryline Pioz (INRAE, UR406 Abeilles et Environnement, Avignon, France).

The Conversation

Activité d’expertise à l’Anses

Activité d’expertise à l’Anses

Christian Mougin est membre de l’Académie d’Agriculture de France. Il a une activité d’expertise à l’Anses.

Laure Mamy ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d’une organisation qui pourrait tirer profit de cet article, et n’a déclaré aucune autre affiliation que son organisme de recherche.

ref. Pesticides : mieux les évaluer pour mieux protéger notre santé et limiter la contamination de l’air, des eaux et des sols – https://theconversation.com/pesticides-mieux-les-evaluer-pour-mieux-proteger-notre-sante-et-limiter-la-contamination-de-lair-des-eaux-et-des-sols-282323

Le cyborg, ce corps-machine qui nous invite à explorer l’histoire et le futur des hybridations

Source: The Conversation – in French – By Jessica Ragazzini, Chercheuse associée, Université de Strasbourg; Université du Québec en Outaouais (UQO)

Illustration de couverture de l’ouvrage _Arts et Cyborgs. Pensées et imaginaires des corps-machines_.

En proposant une archéologie des imaginaires du corps-machine – des mythes antiques aux pratiques féministes, queer, afrofuturistes et crip – l’ouvrage Arts et Cyborgs. Pensées et imaginaires des corps-machines retrace les usages esthétiques et politiques de l’hybridation, tout en situant les controverses contemporaines liées à l’intelligence artificielle dans une longue histoire des artefacts anthropomorphes.


Depuis plusieurs années, l’intelligence artificielle (IA) suscite une attention croissante, tant dans les pratiques artistiques que dans les travaux universitaires. Deux postures tendent à structurer, parfois de manière caricaturale, les débats qui l’entourent : d’une part, elle suscite l’enthousiasme pour les formes inédites d’interaction et de co-production entre humain et machine ; d’autre part, elle provoque une grande inquiétude face aux risques d’appauvrissement des interprétations du monde, de standardisation des formes et de réification du vivant.

Dans l’un comme dans l’autre cas, la proximité supposée d’une machine dont « l’intelligence » qui serait comparable à celle de l’être humain, voire susceptible de la dépasser, est au cœur de la polarisation. Or, cette fascination et les peurs qu’elle charrie ne surgissent pas ex nihilo. En effet, depuis l’Antiquité, les créations artificielles, les figures anthropomorphes et les récits de création constituent des réflexions privilégiées qui éprouvent les limites du vivant et permettent de repenser la définition de l’être humain.

Dans ce contexte, l’ouvrage Arts et Cyborgs. Pensées et imaginaires des corps-machines propose une synthèse de l’histoire longue de la fascination pour les objets et corps anthropomorphes. Ce projet retrace une généalogie à la fois artistique, philosophique et curatoriale de l’hybridation entre chair et technique, représentation centrale de la culture contemporaine et passée. Rejetant l’idée d’un inventaire exhaustif, cette publication présente les continuités et ruptures afin d’offrir des outils conceptuels permettant de situer les formes actuelles dans un réseau de références plus ancien et complexe.

Une figure-limite

Forgé en 1960 par les scientifiques Nathan S. Kline et Manfred E. Clynes, le terme « cyborg » désigne un organisme cybernétique susceptible d’adapter le corps humain aux conditions d’une vie extraterrestre. Au-delà de cette origine technoscientifique, l’imaginaire cyborg s’est rapidement constitué comme une construction du rapport à soi et aux mondes à titre de figure-limite, au sein de laquelle se rejouent les partages entre organisme et artefact, autonomie et contrôle, vulnérabilité et puissance.

Réinvestie par les luttes et mouvements sociaux à partir des années 1970, la figure du cyborg contribue à déstabiliser les catégories binaires, en particulier celles du genre, et à interroger les régimes de normalisation qui organisent les rapports sociaux et sociétaux.

Cette fécondité critique est théorisée de manière décisive par la philosophe et biologiste Donna Haraway dans son Manifeste Cyborg dans lequel le cyborg apparaît comme un paradigme politique qui remet en question les logiques de pouvoir fondées sur des oppositions naturalisées (corps/objet, vivant/machine, nature/culture). En ce sens, il ouvre un horizon spéculatif et prospectif qui mène à envisager des futurs possibles où les catégories mêmes par lesquelles nous décrivons l’humanité et la non-humanité se trouvent reconfigurées, dans un entre-deux instable entre biologie et technologie.

Échapper aux normes sociales et symboliques

Si la culture contemporaine attribue au cyborg une myriade de définitions parfois concurrentes ou même contradictoires, celles-ci s’inscrivent dans une histoire plus vaste des représentations de la figure humaine. Dès l’Antiquité, des récits tels que l’histoire de Pygmalion ou celle d’Hermaphrodite déplacent des frontières réputées stables entre être et matière (la pierre animée), entre masculin et féminin, entre fabrication et engendrement montrant la complexité des modes d’existence qui échappent finalement aux nomenclatures fixes et stéréotypées. Au fil des siècles, de tels mythes se sont multipliés devenant des matrices narratives par lesquelles les artistes ont pu imaginer des formes abolissant ou contestant les normes sociales et symboliques de leur époque.

Parallèlement, la philosophie a élaboré des cadres conceptuels visant à préciser ce qui distingue l’être humain du non-humain, mais aussi ce qui les relie tels que l’agentivité, la sensibilité, le langage, la technique, etc. Les controverses actuelles relatives à l’IA – notamment lorsque des systèmes génératifs produisent images ou sons à partir de corpus préexistants – réactivent ainsi des questions anciennes : ces productions relèvent-elles d’une forme de création analogue à celle d’un artiste mobilisant un bagage culturel ? Les deux types de productions sont-elles radicalement opposées du fait de l’impossible subjectivité humaine du programme génératif ? Ces débats ne sont pas sans rappeler ceux prononcés lors de l’apparition de la photographie qui révélaient déjà les craintes d’usage des dérives d’une image réaliste indirectement produite par l’être humain.

Envisager des transformations sociétales

Ainsi, si la photographie est aujourd’hui largement reconnue comme un médium artistique à part entière, son histoire rappelle que les technologies visuelles ne sont jamais neutres. Au début du XXe siècle, l’usage volontiers patriarcal de la photographie de la part de certains artistes futuristes et surréalistes contraste avec les expérimentations de Hannah Höch ou de Claude Cahun, qui en font un outil de déstabilisation des identités, des normes de genre et des régimes de représentation.

De manière comparable, l’hybridation technologique contemporaine par laquelle la figure cyborg prend forme dans les œuvres féministes et queer constitue un contrepoint critique face à la circulation massive sur les réseaux sociaux, d’images d’IA reconduisant des stéréotypes sexistes et anti-LGBTQI2A+.

Dans ces pratiques, la figure cyborg ne se réduit pas à une iconographie de science-fiction, elle devient un dispositif de pensée pour envisager des transformations sociétales, renverser des hiérarchies corporelles et imaginer d’autres normes possibles. C’est aussi ce que montrent les artistes a frofuturistes qui articulent la spéculation politiquement engagée ou encore les artistes crip dont le corps perçu aujourd’hui en situation de handicap, pourrait se voir demain doté d’une mécanique surpuissante qui le transformerait en un nouvel idéal corporel à atteindre.

Faire place à l’erreur

Le corps cyborg ouvre un horizon de capacités « surhumaines » ou « surbiologiques ». Toutefois, il demeure simultanément exposé aux failles, aux incompatibilités et aux dysfonctionnements propres aux dispositifs techniques et aux vulnérabilités de la chair. Dans les pratiques artistiques, ces incidents constituent des matériaux heuristiques qui mettent en évidence les infrastructures, les normes et les idéologies inscrites dans notre monde contemporain. Le glitch, le bug ou la panne peuvent alors être revendiqués comme motifs esthétiques, en rupture avec les impératifs d’optimisation, de fluidité et d’hyperproductivité qui accompagnent souvent l’imaginaire technocapitaliste du progrès technoscientifique.

Faire place à l’erreur revient à ouvrir un champ de futurs possibles où l’altération devient souhaitable, précisément parce qu’elle introduit de l’indéterminisme qui échappe à toute tentative de contrôle humain ou technologique. Ce geste reconfigure les narratives historiques de réussites de l’inventivité et du génie de l’humanité, il ouvre des brèches dans les récits linéaires du progrès en perturbant sa frise chronologique. Les dysfonctionnements apparaissent ainsi comme étant des leviers critiques pour penser l’histoire autrement à travers ses trous, ses silences, ses répétitions, ou ses accélérations angoissantes.

Ouvrir le champ des possibles

L’intérêt des imageries cyborg réside dans leur polysémie et dans l’antagonisme possible de leurs usages, ces figures peuvent aussi bien perpétuer des fantasmes de maîtrise que soutenir des politiques de l’émancipation. C’est pourquoi elles requièrent une lecture contextualisée, attentive à la fois aux symboliques mobilisées, aux enjeux contemporains et aux dimensions spéculatives qui ouvrent la porte à des futurs pessimistes autant qu’optimistes. En ce sens, l’ouvrage Arts et Cyborgs. Pensées et imaginaires des corps-machines vise à proposer une histoire des imaginaires non hégémonique. En articulant archéologie des formes, analyse des discours et attention aux pratiques curatoriales, il ouvre la voie à de nouvelles recherches sur les manières dont les corps – réels, représentés ou fictionnés – deviennent des lieux d’une reconfiguration des sensibilités, des nomenclatures, des pouvoirs et des possibles.


Arts et Cyborgs. Pensées et imaginaires des corps-machines a été publié par les éditions Double Ponctuation.

The Conversation

Les auteurs ne travaillent pas, ne conseillent pas, ne possèdent pas de parts, ne reçoivent pas de fonds d’une organisation qui pourrait tirer profit de cet article, et n’ont déclaré aucune autre affiliation que leur organisme de recherche.

ref. Le cyborg, ce corps-machine qui nous invite à explorer l’histoire et le futur des hybridations – https://theconversation.com/le-cyborg-ce-corps-machine-qui-nous-invite-a-explorer-lhistoire-et-le-futur-des-hybridations-281085

Pensions for Botswana’s elderly are growing, but care services are lacking – study tracks 20 years

Source: The Conversation – Africa – By Elena Moore, Professor of Sociology, University of Cape Town

Botswana’s economy is projected to contract by 0.4% in 2026, driven largely by a slowdown in the diamond sector. Diamonds account for a third of fiscal revenues and a quarter of GDP. This means the government has less money to spend, even before making any policy choices.

At the same time, the government has set about reducing debt as a share of GDP by cutting expenditure to stabilise the economy. This combination is forcing difficult decisions about public spending.

A key one is investment in social protection for older people. Over the past two decades, the number of older persons aged 60+ has doubled to about 279,111 people (roughly 8% of the population). In coming decades, that number is set to rise even more sharply. While this reflects important gains in life expectancy, it also presents a policy challenge: how to support an ageing population in a context of tightening public finances.

We have between us expertise in long term care systems, public financing and budget analysis. Our recent study sought to tackle this question by examining how the Botswana government has funded elder care over the last 20 years.

We also obtained government data to examine how state spending on older people has evolved over time under various social protection measures. These included the old age pension, destitute programme, disability allowance and war veteran’s allowance, as well as care provision through the home-based care programme.




Read more:
Botswana’s hike of old age pensions hasn’t fixed the problem of who cares for the elderly – new study


Our final report looks at how spending in 2005 compares to spending in 2024-2025, adjusted for inflation to reflect real changes in today’s value, and how these trends correspond with the growth of the older person population.

The key insight of the new report is that while Botswana has significantly expanded its old age pension system, investment in care services for older people has not kept pace.




Read more:
Botswana’s hike of old age pensions hasn’t fixed the problem of who cares for the elderly – new study


The result is a system that provides income support but leaves many without the care they need and an underinvestment in the care economy in Botswana.

A pension success story: at a cost?

Botswana’s old age pension has long been one of the country’s most important social protection programmes. It is universal, meaning all citizens above a certain age qualify, and it has achieved broad reach across both urban and rural areas.

In 2025, the government made two major changes: it lowered the eligibility age from 65 to 60 and increased the monthly benefit.

These reforms have been widely welcomed. For many older people, the pension provides a crucial lifeline, helping to cover food, transport and other basic needs. In a country without unemployment benefits, it often supports entire households, not just individuals.

But this success comes with trade-offs.

The rapid expansion of the pension has absorbed a growing share of the broader social protection budget. This has left less room for other forms of public support, particularly those related to care.

A hidden crisis of care

Ageing is not just about income, it is also about health, disability and the need for care. As people live longer, they are more likely to experience chronic illnesses and multiple health conditions at once. This often leads to increased levels of disability and dependence.

Yet Botswana’s spending patterns suggest that these realities are not being fully addressed.

Pension coverage has expanded. But access to other support programmes has stagnated or even declined. The proportion of older persons receiving the destitute allowance has fallen significantly over the past decade, and disability support reaches only a small fraction of those who need it. While there has been an increase in total spending, there has not been an increase in total spending in real terms per person.

At the same time, spending on community home-based care, a key service that supports older persons in their homes, has decreased in real terms. This is happening despite clear evidence that demand for such services is rising.

Families under pressure

Care for older people in Botswana has traditionally been provided by families. This model is under increasing strain. A previous report on caregiving indicated how the long-term impact of HIV/Aids, combined with migration and rising female employment, has reduced the availability of family caregivers.

Moreover, between 2012 and 2023, female labour force participation increased from 54.9% to 63.4%, meaning fewer women are available to provide full-time care at home.

At the same time, many households face significant economic and infrastructural challenges. Older-people households are often large and multigenerational, yet resources are limited. Nearly half report experiencing food insecurity, and many lack access to basic services such as piped water and sanitation.

In a few isolated cases there are “voluntary” carers supporting older persons. But serious questions remain about their long-term sustainability.

In rural areas, where most older persons live, these challenges are even more pronounced.

Poverty persists despite pensions

Poverty among older people remains a serious concern. Around 11.9% live in extreme poverty, and they are more likely to be poor than any other age group. One reason is that the pension is often stretched across entire households.

At the same time, access to additional assistance is limited. Programmes such as the destitute allowance and disability grant often rely on discretionary assessments by social workers. Many older persons report that these programmes are difficult to access or simply unavailable.

This points to a broader issue: Botswana’s social protection system for older people is becoming increasingly narrow, centred on a single programme while other forms of support fall away.

These challenges are unfolding in a context of fiscal austerity. As the government seeks to reduce deficits and stabilise the economy, public spending is under pressure. But cuts to social services come with risks. Botswana is already one of the most unequal countries in the world. Reductions in social protection and care services are likely to exacerbate these inequalities.

Public services are also under strain. The country faces shortages of healthcare workers and infrastructure. In this context, reducing investment in care could have long-term consequences for both social and economic development.

Rethinking social protection

The current moment calls for a shift in how social protection is understood. Rather than focusing narrowly on pensions, policymakers need to take a broader view, one that includes care as a central component. Investing in care services is not just about meeting immediate needs. It can also create jobs, support households, and contribute to economic growth. Community-based care programmes, disability support, and partnerships with local organisations all offer pathways to strengthen the system.

Across Botswana, community initiatives are already stepping in to fill the gaps. But without stronger public support, these efforts cannot meet the scale of need.

What’s needed is a more balanced approach to spending priorities, one that protects income security while also investing in the public services that enable people to age with dignity.

The Conversation

Elena Moore receives funding from Welcome Trust 225910/Z/22/Z and the International Development Research Centre, Grant No. 110536 – 001

Thokozile Madonko does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

ref. Pensions for Botswana’s elderly are growing, but care services are lacking – study tracks 20 years – https://theconversation.com/pensions-for-botswanas-elderly-are-growing-but-care-services-are-lacking-study-tracks-20-years-281644

How AI can lead to false arrests and wrongful convictions

Source: The Conversation – USA – By Maria Lungu, Postdoctoral Researcher of Law and Public Administration, University of Virginia

AI algorithms such as facial recognition systems produce probabilities, not facts. Matthew Horwood/Getty Images

In Baltimore on Oct. 20, 2025, a 17-year-old student named Taki Allen was sitting outside his high school after football practice when an artificial intelligence-enhanced surveillance camera falsely identified the Doritos bag in his pocket as a gun. Within moments police cars arrived, officers drew their weapons and Allen was forced to his knees and handcuffed while they searched him. All they found was a crumpled bag of chips. The AI’s misidentification and the human decisions that followed turned a normal evening into a traumatic confrontation.

On Dec. 24, 2025, Angela Lipps, a Tennessee grandmother, was released after spending five months in jail because facial recognition software had incorrectly connected her to fraud crimes in North Dakota, a state she had never visited. Police had arrested her at gunpoint while she was babysitting her four grandchildren.

These are unfortunate examples of how AI can lead to mistreatment of people because of technical flaws as well as misplaced human faith in the technology’s supposed objectivity. These cases involve different tools, but the underlying issue is the same. AI systems produce probabilities, and people treat them as certainties.

We are researchers who study the intersection of technology, law and public administration. In researching how police departments use AI and how digital technologies operate in a democratic society, we have seen how quickly the shift from probabilistic prediction to operational certainty happens in practice.

AI policing tools are used in dozens of U.S. cities, although no public registry tracks the full footprint. The tools ingest historical crime data and score neighborhoods on predicted risk so officers can be routed toward the resulting hot spots. The mechanism is straightforward, but its consequence is not. Once a system signals a possible threat, the question is no longer how certain the prediction is but what to do about it. A statistical output turns into a deployment decision, and the uncertainty that produced it gets lost on the way.

A matter of probabilities

When generative AI models such as ChatGPT or Claude respond to human requests, they are not searching a database and pulling out facts. They are predicting the most likely answer based on patterns in data they have been trained on. When asked, “Who invented the light bulb?” the models do not go to a source or fact-check a finding. They generate a statistically probable answer which is “Thomas Edison.” The reply might be right, but it might not capture the full story – such as Joseph Swan’s parallel invention at the same time as Edison’s. The danger arises when people believe that the model is retrieving truth rather than generating likelihoods.

This distinction matters. The most probable response is not the same as a factually verified answer, complete with context.

Police handcuffed teenager Taki Allen at gunpoint after an AI camera system incorrectly indicated he had a gun.

This reality can be highly problematic for policing and law. For example, when law enforcement agencies use AI systems trained on geographical data to estimate where criminal activity is likely to occur, the algorithms analyze historical crime data and geographic patterns. These systems generate statistical risk scores or heat maps for locations based on prior incidents. But such predictions may have little bearing on who was involved in a new crime in the area, even if an algorithm generates information that sounds authoritative.

Some researchers have argued that predictive policing systems do not increase the likelihood that racial minorities will be arrested more often relative to traditional policing practices. The broader concern, however, is not limited to measurable disparities in arrest outcomes alone. It is about how probabilistic predictions can become standardized operational decisions absent further verification.

Artificial intelligence researchers caution against using these models in isolation for crime and legal proceedings or decision-making. Research at the University of Virginia’s Digital Technology for Democracy Lab with police chiefs shows that some law enforcement groups follow strict policies that dictate when technology is used in tandem with, or in place of, human discretion, while others have no such policy.

What most users do not realize is that AI systems rarely produce binary answers: yes or no, a positive identification or a negative one. They generate probabilities. Some systems assign scores that assess the system’s confidence in a prediction. In those cases, engineers set a confidence threshold, a level of certainty that determines when the system should trigger an alert about a possible threat. You can think of this threshold as settings on a control knob. A 95% confidence level, for example, indicates that the model considers its interpretation to be highly likely.

A low threshold catches more potential threats but increases false alarms. A high threshold reduces mistakes but risks missing real dangers. Either way, these algorithmic thresholds are often invisible to the public and are set quietly by vendors or agencies, even though they shape when police action begins.

Angela Lipps was unjustly jailed for more than five months based on a mistake by a facial recognition system.

Where to draw the line

In medicine, these kinds of trade-offs are explicit. Diagnostic tools are calibrated on the relative harm of different errors. In infectious disease settings, for instance, systems that detect infections are often designed to accept more false positives to avoid missing contagious individuals. Then medical professionals look into the human cases. And the algorithm-based decisions are subject to professional standards, ethics reviews and regulatory oversight.

In policing, an AI system must balance false positives, where the system flags a threat that does not exist, and false negatives, where it fails to detect a real danger. The trade-off carries significant consequences. A lower threshold may generate more alerts and allow officers to intervene earlier, but it also increases the risk of mistaken identifications, which happened to Angela Lipps, or escalated encounters like the one Taki Allen experienced. A higher threshold may reduce wrongful interventions but could allow legitimate threats to go undetected.

Some law enforcement agencies argue that acting on imperfect signals is preferable to missing serious risks. But lowering the bar for algorithmic alerts based on probabilistic estimates effectively expands the number of people subjected to police attention. It is important to realize that these thresholds are not neutral features of the technology; they are choices embedded by the creators in the model’s code. Decisions about where to draw the line determine when an algorithmic suspicion becomes a real-world police action, even though the public rarely sees or debates how those thresholds are set.

Limits of optimization

Developers often use several methods to determine where to set a confidence threshold. Techniques such as “receiver operating characteristic curve analysis” examine how changing the threshold for an alert alters the balance between correctly identifying real events and mistakenly flagging harmless ones. Precision–recall analysis examines a similar trade-off, asking how accurate the system’s alerts are relative to the number of incidents it successfully detects.

These approaches could help calibrate systems more responsibly by testing how often an algorithm wrongly flags people or locations. Fine-tuning can improve system performance. But the techniques cannot resolve the underlying question of how much algorithmic uncertainty society is willing to tolerate.

In law, legal standards of proof determine how convincing evidence must be before a judge or jury can rule in favor of a plaintiff or defendant. Courts use formal standards of proof depending on the stakes, such as probable cause, preponderance of the evidence and beyond a reasonable doubt. These standards reflect a societal judgment about how much uncertainty is acceptable before exercising legal authority. A court does not accept a guess or a prediction; it follows a process to weigh evidence. Unlike humans, an AI model does not usually say, “I’m not sure.” A model typically has confidence in its reply, even when the answer is incorrect.

Stakes are rising as AI enters the courtroom, law enforcement, the classroom, the doctor’s office and the public sector. It is important for people to understand that AI does not know things the way many assume it does. It does not distinguish between “maybe” and “definitely.” That is up to us. We believe that technologists should design systems that admit uncertainty and need to educate users about how to interpret AI outputs responsibly.

The Conversation

Maria Lungu is affiliated with the Digital Technology for Democracy Lab at the University of Virginia, Kennesaw State University, and the Center for DI and Digital Policy (CAIDP).

Steven L. Johnson is affiliated with the Digital Technology for Democracy Lab at the University of Virginia.

ref. How AI can lead to false arrests and wrongful convictions – https://theconversation.com/how-ai-can-lead-to-false-arrests-and-wrongful-convictions-281102

How does your brain decide between the road not taken or the same old route? Resolving conflicting memories is key to navigation

Source: The Conversation – USA – By Paulina Maxim, Ph.D. Candidate in Psychology, Georgia Institute of Technology

Which route should you take? The familiar or the unknown? francescoch/iStock via Getty Images Plus

When was the last time you paid attention to your commute? And I don’t mean a couple of feet in front of you, at the car merging into your lane without a blinker. I mean really paid attention to the route you take.

Did you see the landmarks in the distance that make up the city skyline? Did you drive right past the grocery store you promised to stop by at the corner of this Peachtree Street or that Peachtree Street, a struggle Atlanta locals know well?

“Oops! Force of habit,” you might say to yourself as you miss your turn and begin to think about when and where you can turn around.

Relying on familiarity can either facilitate or impede daily navigation. As a researcher studying memory and navigation, I aim to understand how the brain supports spatial navigation and what happens if the cognitive mechanisms for choosing the best route home begin to decline, such as during stress or with aging.

Humans are creatures of habit – at least that’s what people tell themselves when wary of trying something new. But what if a new route is faster or safer than the one you usually take? Would you try it?

Research from my team suggests that people balance between exploration and habit – that is, trying something new or sticking with the familiar – when deciding what route to take. Which navigation strategy someone chooses depends not only on their spatial abilities but on their network of brain regions that support navigation.

Close-up of side view mirror reflecting city skyline and other cars on the road
When was the last time you paid attention to the scenery of your usual commute?
Boonchai Wedmakawand/Moment via Getty Images

A spatial blueprint

Spatial navigation refers to the cognitive ability that helps you travel from one location to another. It may sound simple, but it requires using cognitive functions such as memory, attention, decision-making and assessing potential rewards – never mind the ability to simply perceive the environment itself.

Spatial navigation uses memories of things you consciously experienced. Two types of memory relevant to navigation are what scientists call episodic and semantic.

For example, you might retrieve an episodic memory about a specific event: remembering a detour you took a week ago to drop a package off at the post office, including the traffic and weather that day.

You might also retrieve a semantic memory that’s more factual and knowledge-based: remembering how many blocks away the post office is from the park and the turns you need to make to get there.

Together, these kinds of memory inform your spatial memory, which allows you to retrieve location information. This could be where buildings are in relation to each other or where objects are situated in your house. Spatial memories help form your cognitive map, which is essential for getting around in the world.

Often, these different ways of remembering interact, and you can use one type of memory to inform the other. For example, you’ve become accustomed to your commute to work and know it’s relatively short (semantic memory), but over the past three days you’ve been arriving late due to heavy traffic (episodic memory), so you choose to take a different route next time.

Research from my team has found that disagreements in your brain over possible routes can happen. Different types of memory can come up with different solutions for what route you can take, and this conflict is a big factor in how hard your brain needs to work when navigating an environment.

Responding to new and familiar memories

Habits stem from what researchers call stimulus-response memories. These include the knee-jerk reaction you might have to familiar landmarks – when you perceive these places, your brain signals you to make a turn along your commute without needing to consciously think about it.

Habits are rigid, but they can also be beneficial: By taking care of the navigation for you, habit frees up your brain to have a conversation with someone or plan what to make for dinner when you get home.

When navigating less familiar routes or environments, where habit doesn’t kick in automatically, you rely on brain regions such as the hippocampus to call on detailed memories from recent experiences to help guide the way.

Aerial view of a busy intersection in a city, crowds of people milling about and buildings lit with animated billboards
When visiting a new city, you might rely on your existing mental map of urban environments.
Francesco Riccardo Iacomino/Moment via Getty Images

But let’s say you’re shopping at a new grocery store where most things are where you expect them to be, even though you’ve never been in this particular store before. What happens when your brain experiences both something new and something familiar about an environment?

Researchers have shown that when something about an environment is familiar and aligns with your prior experiences, the prefrontal regions of your brain – those responsible for executive functions such as decision-making – become more active. They can bypass or even inhibit your hippocampus’s ability to form new memories about specific events.

In other words, your brain can weave information about a new experience into your database of existing knowledge, rather than storing it as completely new information with little relation to the past. This process may help fast-track your understanding about new experiences.

Updating cognitive maps

Researchers know that cognitive maps of the environment depend on the hippocampus and its database of memories about specific events. However, I and other researchers argue these maps can also function as a schema – a collection of memories made up of associations between environmental details. You can add new information to these collections and use it to infer new relationships.

Say a new pedestrian bridge is built between the park and the post office. Your brain can more easily weave this new route information into your existing memories compared with learning a new environment from scratch. Similarly, if you just moved to a new town and know very little about the spatial layout, you might rely on your past experiences of towns to infer where something is.

Schemas help you interpret and incorporate new information more quickly.

Using neuroimaging techniques as well as virtual reality programs designed to test a participant’s ability to navigate different routes, my team found that there is likely an interdependent relationship between the brain areas that store memories of specific events and areas that store related information across memories when planning to navigate less familiar places.

New routes are more difficult to follow when they differ from your prior experiences. Thus, a stronger schema helps integrate your knowledge of the spatial relationships between locations and landmarks (such as the distance between the post office and the park) with more general knowledge (such as prior route difficulty). This all informs how you choose to navigate.

Navigating daily life

These memory principles help explain why inconsistencies with your previous experiences can make it so difficult to navigate many aspects of daily life.

Imagine you woke up tomorrow and the GPS on your smartphone was no longer available. How will you plan your route to get to your destination?

You might be used to navigating north from your home to the grocery store – but have you ever tried to navigate to that grocery story from a different location? It’s much harder!

Factors such as stress, aging and general cognitive decline can affect brain function and human behavior. Imagine how much harder that new route to the grocery store is for an older adult.

Relating new information to your prior experiences may help strengthen your schema and make navigation easier. And understanding what processes the brain needs to go through to solve these navigation problems can help you understand why getting around can be challenging.

The Conversation

This work was supported in part by grants from the National Institute on Aging of the NIH.

ref. How does your brain decide between the road not taken or the same old route? Resolving conflicting memories is key to navigation – https://theconversation.com/how-does-your-brain-decide-between-the-road-not-taken-or-the-same-old-route-resolving-conflicting-memories-is-key-to-navigation-279435

Why did ‘Tyrannosaurus rex’ have such short arms?

Source: The Conversation – USA – By Sarah Sheffield, Assistant Professor of Earth Sciences, Binghamton University, State University of New York

Teeth? Big. Arms? Not so much. William_Potter/iStock via Getty Images Plus

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to CuriousKidsUS@theconversation.com.


What did the T. rex use its little arms for? – Aurora, age 11, Pemberton Township, New Jersey


One of the most famous dinosaurs to ever roam across Earth, Tyrannosaurus rex, has filled people’s minds with wonder since the first skeleton was discovered in the early 1900s.

Scientists believe T. rex, or King of the Tyrant Lizards, as its name translates, was a fearsome predator. An adult T. rex was massive in size – approximately 40 feet (12 meters) long and 20 feet (6 meters) tall, weighing as much as an African elephant. Each of its enormous sharp teeth could be near a foot (0.3 meters) in length from the root to the tip.

I’m a paleontologist, and I use fossils to study how animals lived and evolved over long periods of time. One of the coolest things about being a paleontologist is that there are always new questions to ask and new things to learn – even about a super-well-known dino like T.rex, which went extinct just over 65 million years ago.

One T. rex mystery has to do with this giant predator’s relatively tiny arms. Why would it have arms so short that it couldn’t even reach its own mouth? How did it use them?

How ‘short’ is short?

First, let’s define what we mean by “short.”

The biggest T. rex could measure 45 feet (14 meters) from the snout to the tip of the tail, but their arms were only about 3 feet (1 meter) long. On average, a T. rex’s arms were just about 30% of the length of its legs.

In comparison, humans have, on average, arms around 66% of the length of their legs. If people had the same arm proportions as a T.rex, a 6-foot (1.8 meters) tall person would have arms only 10 or 12 inches (25 to 30 centimeters) long!

T. rex isn’t the only dinosaur with such short arms. The evolutionary trend toward shorter arms in theropods – the larger group of meat-eating, two-legged dinosaurs that T. rex belongs to – happened multiple times. Similar to how wings separately evolved in different animals – like birds and bats – traits can emerge many times in evolutionary history.

You can see the shortening of T. rex arms as a pattern in its family tree, as earlier relatives had proportionally longer arms.

Lots of schoolchildren gathered around a T. rex skeleton on display in a museum
Fossil skeletons of Tyrannosaurus rex make clear that the dinosaur itself was very big, even if its arms were proportionally small.
John Zich/AFP via Getty Images

How did they use their mini-arms?

Short arms don’t seem to have been a problem for these mighty dinosaurs. T. rex was a successful carnivorous species that existed for over a million years. They only went extinct when an asteroid hit the Earth, causing a global mass extinction.

Scientists have suggested a few ideas to possibly explain how T. rex used their arms. Maybe they were used as some kind of social display that could impress other T. rex – kind of like the bright feathers of a peacock that can attract potential mates.

But male and female T. rex skeletons don’t show the major differences that paleontologists would take as clues that they relied on social displays to attract mates. And while animal behavior can sometimes be preserved, such as in bite marks or fossilized footprints, it’s rare to have enough fossil data to draw clear conclusions.

Maybe T. rex used their arms as weapons to attack or hold down prey. But these options seem unlikely since T. rex’s huge jaws would have made contact with an enemy or prey before the short arms would have been able to reach it.

Some scientists have recently hypothesized that T. rex‘s short arms were an adaptation to competition with other carnivores. If multiple predators were feeding on a carcass, one could get hurt by accidental bites or even intentional warning bites for getting too close. Shorter arms would be less likely to get chomped. Similar things occur today with territorial carnivores, like Komodo dragons.

Two Tyrannosaurus dinosaurs face off over a downed prey carcass
Scientists have suggested that in a feeding frenzy, shorter arms would potentially be easier to keep out of the way of chomps from other T. rex.
Mark Garlick/Science Photo Library via Getty Images

Maybe the arms didn’t have a purpose

Another possibility is that the arms served little or no purpose at all, so over time, they became vestigial. That’s the scientific term for body parts that don’t have clear purposes anymore, but are still passed down through evolution.

One example is a whale’s hindlimbs. Whales evolved from mammals that lived on land that had large legs to move around. The bones are still present in today’s whales, but have gotten much smaller over millions of years and have no function.

Some scientists have suggested a different idea: T. rex’s arms may have evolved to be smaller as another body part grew larger. The fossil record reveals that arms got shorter as theropod skulls got larger across many different dinosaur groups, including T. rex. Larger skulls likely would have made it easier to hunt and eat larger prey.

Researchers can use mathematical equations to accurately predict theropod arm length if they know the animal’s skull size and length of its upper leg bone, the femur. It turns out that larger skulls are strongly linked to shorter arms in theropods.

The reason for the change in arms, however, isn’t as clear. Some scientists have argued that the smaller arms could have helped with balance as the head got larger, but others aren’t so sure. In evolution, there isn’t always a reason why a change occurs – sometimes, changes just happen. In this case, we don’t yet know if there was a benefit for the arms to get smaller as heads got larger.

Artist's rendition of a T. rex in a misty forest.
However they got that way, small arms don’t seem to have been an issue for these big predators.
Orla/iStock via Getty Images Plus

So for now, we don’t really know how T. rex used its arms or why they evolved to be so small, proportionally. As scientists find new data, we will continue to test hypotheses to better understand why this tiny-arm trend occurred so many times in theropod evolution. That’s what makes science so exciting – a future fossil discovery could be the missing puzzle piece that helps us answer these questions.

Sarah Sheffield describes – and her students act out – some of scientists’ hypotheses about T. rex arms.

Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to CuriousKidsUS@theconversation.com. Please tell us your name, age and the city where you live.

And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.

The Conversation

Sarah Sheffield does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

ref. Why did ‘Tyrannosaurus rex’ have such short arms? – https://theconversation.com/why-did-tyrannosaurus-rex-have-such-short-arms-273438

Delta-8, delta-9, THCA? What sets the different THC forms available in regulated cannabis products apart

Source: The Conversation – USA – By Aaron W. Harrison, Assistant Professor of Chemistry, Trinity University

Commercially available THC products are displayed at a dispensary in New York. AP Photo/Angelina Katsanis

Hemp products have exploded across the United States, even in the majority of states where recreational marijuana remains illegal. This surge came after the 2018 Farm Bill removed hemp from the Controlled Substances Act and made cannabis products derived from hemp, defined as those containing less than 0.3% delta-9 tetrahydrocannabinol – commonly known as THC – legal. But the types of THC products available and the regulations around them, which vary by state, can be confusing.

A common question I get as a chemist is about the differences between the various delta THCs, and about the actual amounts of THC in the available products. There’s delta-8, delta-9, delta-10 and THCA. The amounts of THC in legally infused drinks and edibles also varies, with products most often containing 5 or 10 milligrams.

Knowing the difference between these compounds, and how much THC is in what you’re buying, goes a long way toward making informed choices as a consumer.

THCA and delta-9 THC

THC compounds are a subset of cannabinoids, which include any compound that interacts with the cannabinoid receptors in your body. THC is technically a family of compounds including delta-8, delta-9 and delta-10 THC, which all have similar chemical structures and are psychoactive – meaning they can alter your mood and perception and produce a “high.”

However, not all cannabinoids are psychoactive. For example, cannabidiol, or CBD, interacts with the same receptors, but through different mechanisms, so it does not produce a high.

9-tetrahydrocannabinolic acid, THCA, is the major cannabinoid found in the cannabis plant. THCA itself does not produce a high, however. It first needs to undergo a chemical reaction that generates a psychoactive compound: delta-9 THC.

These two compounds have different chemical structures. THCA has an extra group of atoms attached that must be removed to produce delta-9 THC. Under heat, this group breaks away from the rest of the compound, creating delta-9 THC. So, when the plant is burned or cooked, THCA transforms into delta-9 THC.

The 2018 Farm Bill measured only the delta-9 THC – not THCA – present in a hemp plant. So a hemp plant could have, say, 25% THCA and only 0.2% delta-9 THC and still be legal, as it has less than 0.3% delta-9 THC. But as soon as you heat it, the THCA will convert to psychoactive delta-9 THC.

However, in November 2025, the Agriculture Appropriations Act redefined hemp by limiting the total THC, including THCA, to 0.3% on a dry weight basis.

Changing regulations

This new rule will go into effect in November 2026 and significantly affect the potency of smokable hemp products. In the plant itself, the cannabinoids make up a large percentage of the flower’s dry weight. High-potency cannabis strains have THCA concentrations from 20% to 30% by dry weight – far above the 0.3% total THC threshold. This redefinition would effectively render the majority of these products illegal under federal law.

The math for edibles like gummies and seltzers is different, so the dry weight rule alone does not affect these products.

Consider a 12-ounce THC-infused drink: The total dry weight of the product would only need to be about 3.3 grams per 10 milligrams of delta-9 THC – a common higher-end dosage – to fall at exactly the 0.3% threshold. A 12-ounce can of seltzer weighs around 355 grams, so 10 milligrams of delta-9 THC in a 12-ounce drink easily passes the weight threshold.

Even a very small edible like a gummy easily meets this weight threshold. For instance, a single Starburst candy weighs 5 grams, well above the 3.3-gram minimum needed for a 10-milligram dose to be under the 0.3% limit.

To close this loophole, the new law adds a separate rule: Any final hemp-derived product containing more than 0.4 milligrams of THC per container is no longer legal. That’s well below a single dose of any commercially marketed THC beverage or edible.

However, the debate isn’t over. Lawmakers introduced amended legislation in April 2026 that will give states autonomy in hemp regulation as opposed to a blanket federal ban.

What about delta-8 and delta-10 THC?

Delta-8 and delta-10 THC are what chemists call isomers of the delta-9 THC. They have the same chemical formula but different chemical structures. It’s hard to even tell the difference looking at the molecules. One of the double bonds just shifts its position by one spot in the ring.

Like delta-9, delta-8 and delta-10 THC are also psychoactive and bind cannabinoid receptors in the body in a similar way.

While they do occur naturally in cannabis plants, the concentrations are far lower than THCA and delta-9 THC. For commercial products, they must be produced synthetically, which has raised concerns about chemical contamination from manufacturing.

Some evidence suggests that these alternate forms are less potent than delta-9, but scientists will need to conduct more research to determine whether that’s true.

These compounds fell outside the original calculation in the 2018 Farm Bill, which limited only delta-9 – effectively acting as another loophole. But the recently proposed total THC standard closes it by accounting for all types of THC. State legislation still varies substantially when it comes to hemp-derived products.

In April 2026, the Trump administration rescheduled medical marijuana from Schedule I to Schedule III. This move could potentially add to the regulatory confusion, but it will lower research barriers and help scientists address basic questions about THC’s potency, how the body metabolizes it and its therapeutic potential.

Underlying all these complex debates around the legality of hemp versus marijuana and recreational versus medical uses at the state and federal levels lies a single molecule: delta-9 THC.

The Conversation

Aaron W. Harrison does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

ref. Delta-8, delta-9, THCA? What sets the different THC forms available in regulated cannabis products apart – https://theconversation.com/delta-8-delta-9-thca-what-sets-the-different-thc-forms-available-in-regulated-cannabis-products-apart-280008

What to do if someone you know in Philadelphia or elsewhere is detained by ICE

Source: The Conversation – USA – By Jennifer J. Lee, Associate Professor of Law, Temple University

A handout photo provided by U.S. Immigration and Customs Enforcement of a worksite enforcement operation at a car wash in Philadelphia on Jan. 28, 2025.
U.S. Immigration and Customs Enforcement via Getty Images

If someone you know is detained by U.S. Immigration and Customs Enforcement, it can be incredibly challenging to find and communicate with them.

For example, it can take several days just to confirm where they are. Even after locating a loved one, it is possible to lose track of them again, as ICE regularly moves people between facilities without notice.

I’m a law professor at Temple University in Philadelphia, where I work with immigrant rights organizations on issues of ICE arrest and detention.

Here’s what we know about how and where ICE is holding people as of May 2026.

A confusing web of detention facilities

When a person is arrested by ICE, the lack of a centralized immigration detention system makes it hard to figure out where they are.

For ICE detention, the federal government can contract with counties for county jail space or to execute service agreements with private prison companies. ICE also contracts with the Federal Bureau of Prisons to hold immigrants in their facilities.

Pennsylvania is no exception to this patchwork system. Four county jails – in Pike, Clinton, Cambria and Franklin counties – have contracts with the federal government to detain immigrants for ICE. Pike County, for example, received US$16 million from ICE in 2024 and 2025 for use of its jail.

Further, ICE contracts with Centre County so the county can serve as a pass-through for payment to the private prison company, the Geo Group, which runs the Moshannon Valley Processing Center. Moshannon is the largest detention center in the Northeast with 1,876 beds. This pass-through system allows the federal government to avoid the burdensome Federal Acquisition System for contractors. That purchasing system is governed by uniform policies that apply to all federal agencies that enter into contracts for services to ensure that business is conducted with integrity, fairness and transparency.

ICE pays millions of dollars each month to operate the Moshannon Valley facility.

Most recently, ICE set up contracts with two Bureau of Prison facilities in Pennsylvania to hold immigrants: the federal detention center in Philadelphia and the federal prison FCI Lewisburg.

Over 2,000 immigrants in detention in PA

After a person has been arrested by ICE, major federal policy changes that are intended to keep people locked up or have them deported make it difficult to get that person released.

For example, ICE has issued new guidance that expands who is subject to mandatory detention without access to a bond hearing to include anyone who entered the U.S. without a visa. This policy is currently being legally challenged by the ACLU along with other groups.

Additionally, ICE releases many fewer people. Under federal law, ICE has the discretion to release most people, unless they fall into a specialized category of “criminal aliens.” Previously, people were released on parole or on their own recognizance, sometimes with an order of supervision or bond.

As a result, immigration detention has reached unprecedented levels.
Over 70,000 people were held in immigration detention in January 2026. As of April 2, 2026, over 2,000 people were held in immigration detention in Pennsylvania.

Crowd of people with one holding a sign that reads 'Sergio is one of us' and another holding a sign that reads 'We stand with Sergio'
Residents of Danville, Pa., hold a candlelight vigil for local business owner Sergio Chavez Jimenez after he was arrested by ICE on Dec. 27, 2025, and detained at the Clinton County Correctional Facility.
Paul Weaver/SOPA Images/LightRocket via Getty Images

Isolated from family and legal advice

Once arrested, ICE detainees have a hard time contacting the outside world.

Upon arrival at a facility, they are stripped of their belongings, including their cellphone. They must pay for telephone calls to their family or get others to pay by putting money in their commissary account.

Further, ICE detention facilities are often outside of major urban areas and far from legal services and community support. Moshannon, for example, is over 100 miles from any nonprofit immigration attorneys who provide representation to people in immigration removal proceedings.

Previously, the federal government funded a Legal Orientation Program where nongovernmental legal services offered information, referrals and representation to those in detention. In 2025, the Department of Justice ended the program, justifying its termination based on the executive order entitled “Protecting the American People Against Invasion.” Section 19 of that executive order relates to reviewing, pausing or terminating contracts, grants or other agreements with nongovernmental organizations that support or provide services “to removable or illegal aliens.”

Out-of-state transfers are common

ICE’s movement of people without notice across different facilities is a long-standing practice. However, a recent UCLA study found that out-of-state transfers of noncriminal Latino detainees jumped from 18% to 55% after President Donald Trump’s reelection in 2024.

Transfers are mostly about ICE’s own efficiency in maximizing the filling of bed space. Some advocacy organizations have alleged that transfers are conducted for retaliatory reasons against people who make requests or complain. Transfers are not only disorienting for the person involved but also impede communication with family and access to counsel.

How to find someone in ICE detention

Several online guides provide information about how to locate someone after an ICE arrest and how to prepare their family in case of future arrest.

Here are some key tips.

1. Use the ICE online detainee locator.

The locator requires either a person’s country of birth and alien registration number – called an “A number” – or their full name and date of birth. A person might have an A number if they have a past or present case with the government, including having applied for a green card or asylum. It can take 48 hours for ICE to enter information about the person into its database so it can be picked up by the online locator. The name must be an exact match with what was entered into the system.

Webpage of U.S. Immigration and Customs Enforcement
This online search tool can help locate an adult detainee in ICE or Customs and Border Protection custody.
U.S. Immigration and Customs Enforcement

2. Contact the ICE field office.

The Philadelphia field office covers Delaware, Pennsylvania and West Virginia. If you are a noncitizen, you might want a U.S. citizen to do this for you out of an abundance of caution, because ICE records information about the person calling. Call 215-656-7164 or email Philadelphia.Outreach@ice.dhs.gov.

3. Contact the consulate.

In many instances, ICE is supposed to notify the consulate of the arrested person’s home country within 72 hours.

4. Reach out to community groups, attorneys and elected officials.

In Philadelphia, community groups such as Asian Americans United, Juntos and New Sanctuary Movement, or the statewide Pennsylvania Immigration Coalition, might be able to help you. An attorney might also be able to help you. Here is a list of nonprofit legal service providers in Pennsylvania.

Further, you can ask for help from your federal elected officials, such as your congressional representative or Sens. John Fetterman or Dave McCormick. If you have a more direct relationship with a local elected official, such as your city council member, it cannot hurt to see whether they can also help you.

How to prepare in advance

If you know someone who is at risk of arrest by ICE, you can help them prepare in advance. Tell them to:

1. Keep copies of their documents in a secure space.

This includes their A number as well as immigration documents, passport, birth certificate, marriage certificate, tax returns and any employment and medical records. If they have children, make sure to include their passports, birth certificates and medical records.

2. Memorize important phone numbers.

They should know the numbers of family members and their attorney in case their cellphone is taken from them.

3. Have an emergency plan.

A family preparedness plan includes designating a caregiver for children in case a parent or guardian is arrested. They should also consider filling out documents that may help a family member or friend to care for their children if they are unavailable because of detention or deportation. These include forms that provide temporary guardianship or custody of minor children, consent for medical care of minor children and information for the Philadelphia School District.

Philadelphia Legal Assistance provides free downloadable packets in English and in Spanish to build a family preparedness plan.

Read more of our stories about Philadelphia and Pennsylvania, or sign up for our Philadelphia newsletter on Substack.

The Conversation

Jennifer J. Lee does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

ref. What to do if someone you know in Philadelphia or elsewhere is detained by ICE – https://theconversation.com/what-to-do-if-someone-you-know-in-philadelphia-or-elsewhere-is-detained-by-ice-281406

When you don’t have the facts, argue the law: How Trump’s EPA is limiting its own ability to protect public health far into the future

Source: The Conversation – USA (2) – By Janet McCabe, Visiting Professor of Law and Environmental Affairs, Indiana University

The Trump administration is trying to tie the hands of future administrations when it comes to regulating pollution, including greenhouse gas emissions. Chris Sattlberger/Tetra Images via Getty Images

As the Trump administration moves to weaken America’s air pollution rules, it is deploying new legal interpretations that are intended to tie the hands of future administrations for years to come.

In practice, the changes limit the Environmental Protection Agency’s authority under the Clean Air Act. The result allows EPA officials to ignore science, data and the adverse effects their decisions will have on public health and the environment.

But the new interpretations are also designed to apply not just to the rule in which they are first set forth but into the future.

If affirmed by the U.S. Supreme Court in inevitable legal challenges, these interpretations could make it harder for future administrations to restore the public health protections that the Trump administration eliminates. They could also make it difficult to update rules to respond to new information about health risks.

Typically, moves to weaken pollution regulations through novel legal interpretations would have a good chance of being overturned in court. But the EPA’s new interpretations are strategically designed to appeal to the current U.S. Supreme Court’s view of federal agencies’ authority, especially in light of the court’s 2024 ruling in Loper Bright v. Raimondo. In that case, the court overturned what’s known as the Chevron doctrine. A 1984 Supreme Court ruling had established that courts should defer to executive agencies’ legal interpretations of their governing statutes when the text of the law was ambiguous or left gaps. That deference no longer applies.

As a former EPA appointee who helped write and review dozens of regulations under the Clean Air Act during the Obama and Biden administrations, I find these efforts to prevent the EPA from doing its job of protecting public health and the environment to be alarming. Here are two examples of how the new interpretations are playing out.

Blocking future climate regulations

In February 2026, the EPA rescinded its 2009 endangerment finding, a determination under the Clean Air Act that carbon dioxide and five other greenhouse gases “may reasonably be anticipated to endanger public health or welfare” because they contribute to climate change.

The endangerment finding was the scientific and legal basis for EPA rules requiring automakers, power plants and oil and gas operations to cut their greenhouse gas emissions. Erasing it would make it easier for the Trump administration to eliminate greenhouse gas regulations.

Rather than try to challenge the science of climate change, which would be difficult given the growing mountain of evidence, the Trump EPA relied on legal arguments that were intended to dispense forever with the EPA’s ability to regulate greenhouse gas pollutants under the Clean Air Act.

Two men walk toward a podium. One of them, Zeldin, is grinning. The promotional sign reads 'Largest Deregulation in History
President Donald Trump and U.S. Environmental Protection Agency Administrator Lee Zeldin arrive for a White House event to announce a rollback of the 2009 Endangerment Finding on Feb. 12, 2026.
Anna Moneymaker/Getty Images

Among the administration’s numerous arguments, two stand out:

First, the Trump EPA says the Clean Air Act should be read to limit the EPA’s authority to regulate air pollution only if its harm to the public is “through local or regional exposure.”

That would mean contributions from U.S. sources to global air pollution, no matter how demonstrable or how much they endanger Americans, are not covered by the Clean Air Act.

Second, the Trump EPA says that reducing greenhouse gas emissions from motor vehicles and engines would be “futile.” It points to global climate modeling that suggest these reductions would not meaningfully reduce the harm to public health and welfare.

What that argument fails to mention is that actions by people around the world to reduce emissions across different sectors add up. Motor vehicle emissions are the No. 1 contributor of U.S. emissions. If this sector is too small to regulate, then nothing is big enough.

Each of these interpretations is contrary to positions that the EPA took in the original endangerment finding, which the D.C. Circuit Court of Appeals upheld in 2012.

Allowing more toxic air pollutants

A second example involves the EPA’s proposal on March 17, 2026, to weaken pollution restrictions on businesses that sterilize medical equipment using ethylene oxide, a known carcinogen.

In that proposal, the EPA is also changing a legal interpretation in a way that would constrain the agency’s ability to protect human health into the future, this time from emissions of toxic air pollutants.

The Clean Air Act, under Section 112, establishes a methodical program for the EPA to regulate industries that emit significant quantities of air pollutants that can cause cancer, birth defects, genetic mutations or neurological harm, or harm reproductive health.

The EPA reviews how facilities control their emissions and sets standards that require all facilities to meet what the best-controlled sources are doing. But Section 112 has an important provision called “residual risk” review: Eight years after the EPA sets the first technology-based standards, it must determine whether the public health risk posed by emissions from the facilities after controls are added is acceptable.

In 2024, the EPA updated its hazardous air pollution rule for facilities that use ethylene oxide to sterilize medical equipment sensitive to steam heat, such as devices containing plastic, rubber or electronic components. Because recent research showed that ethylene oxide posed a much higher risk of cancer than previously thought, the EPA also updated its 2006 residual risk finding and required additional safeguards.

The Trump EPA is now arguing that the agency can assess residual risk only once, even if more recent information shows that the health risk is unacceptably high.

By constraining its own authority, the EPA is withholding standards that would protect thousands of people from a higher risk of cancer. It is also creating a legal precedent that will justify weakening other standards. Those include standards for chemical manufacturing facilities that the Biden EPA updated in 2024 through residual risk review.

That precedent would also prohibit the EPA in the future from taking into account new information about the health effects of any regulated hazardous air pollutant from any type of industry the EPA regulates under Section 112 of the Clean Air Act, including petroleum refineries, chemical manufacturing and paper mills.

Arguing the law

These rules are just two examples of the administration’s “if you don’t have the facts, argue the law” approach.

If the administration’s strategy works, the American public may be living, and dying, with the consequences of these industry-friendly regulations for years to come.

The Conversation

Janet McCabe is a volunteer with the Environmental Protection Network and has held several appointed positions at the United States Environmental Protection Agency. Consistent with the Indiana University Statement of Policy on Institutional Neutrality, the comments contained in this communication are solely my views and are not intended to be construed, and shall not be construed, as the views of Indiana University or comments made on behalf of or by Indiana University.

ref. When you don’t have the facts, argue the law: How Trump’s EPA is limiting its own ability to protect public health far into the future – https://theconversation.com/when-you-dont-have-the-facts-argue-the-law-how-trumps-epa-is-limiting-its-own-ability-to-protect-public-health-far-into-the-future-282351