Despite all the likes, literallys and dropped g’s, English isn’t decaying before our eyes

Source: The Conversation – USA (2) – By Valerie M. Fridland, Professor of Linguistics, University of Nevada, Reno

Fear not: There isn’t anything that needs saving. LisaStrachan/iStock via Getty Images

As a linguistics professor, I’m often asked why English is decaying before our eyes, whether it’s “like” being used promiscuously, t’s being dropped deleteriously or “literally” being deployed nonliterally.

While these common gripes point to eccentric speech patterns, they don’t point to grammatical annihilation. English has weathered far worse.

Let’s start with something we can all agree on: Old English, spoken from approximately A.D. 450 to 1100, is pretty unintelligible to us today. Anyone who’s had the pleasure of reading “Beowulf” in high school knows how different English back then used to sound. Word endings did a lot more grammatical work, and verbs followed more complicated patterns. Remnants of those rules fuel lingering debates today, such as when to use “whom” over “who,” and whether the past tense of “sneak” is “snuck” or “sneaked.”

The language went on to experience centuries of tumult: Viking invasions, which introduced Old Norse influence; Anglo-Norman French rule, which shifted the language of the elite to French; and 18th-Century grammarians, who dictated norms with their elocution and grammar guides.

In that time, English has lost almost all of the more complex linguistic trappings it was born with to become the language we know and – at least, sometimes – love today. And as I explain in my new book, “Why We Talk Funny: The Real Story Behind Our Accents,” it was all thanks to the way that language naturally evolves to meet the social needs of its speakers.

From dropping the ‘l’ to dropping the ‘g’

The things we tend to label as “bad” or sloppy English – for instance, the “g” that gets lost from our -ing endings or the deletion of a “t” when we say a word like “innernet” – actually reflect speech habits that are centuries old.

Take, for example, “often.” Originally spoken with the “t,” that pronunciation gradually became less favored around the 15th century, alongside that “l” in “talk” and the “k” in know. Meanwhile, the “s” now stuck on the back of verbs like “does” and “makes” began as a dialectal variant that only became popular in 16th-century London. It gradually replaced “th” whenever third persons were involved, as in “The lady doth protest too much.”

While dropping the “l” in talk may have been initially frowned upon, today it would be strange if you pronounced the letter. And the shift makes sense: It smoothed out some linguistic awkwardness for the sake of efficiency.

If people learned to look at language more like linguists, they might come around to seeing that there is more than one perspective on what good speech consists of.

And yes, that absolutely is a sentence ending with a preposition – something many modern grammar guides discourage, even though the idea only took hold after 18th-century grammarian Robert Lowth intimated it was a less elegant choice based on the model of Latin.

Though Lowth voiced no hard and fast rule against it, many a grammar maven later misconstrued his advice as an admonition. Just like that, a mere suggestion became grammatical law.

The rise of the grammar sticklers

Many of today’s ideas about what constitutes correct English are based on a singular – often mistaken – 19th-century view of the forces that govern our language.

In the late 18th century, the English-speaking world began experiencing class restructuring and higher literacy rates. As greater class mobility became possible, accent differences became class markers that separated new money from old money.

Emulation of upper-crust speech norms became popular among the nouveau riche. With literacy also on the rise, grammarians and elocutionists raced to dictate the terms of “proper” English on and off the page, which led to the rise of usage guides and dictionaries that were eager to sell a certain brand of speech.

Another example of grammarian angst reconfiguring the view of an otherwise perfectly fine form is the droppin’ of the “g.” It became so tied to slovenly speech that it was branded with an apostrophe in the 19th century to make sure no one missed its lackadaisical and nonstandard nature.

Up until the 19th century, however, no one seemed to care whether one pronounced it as “-in” or “-ing.”

In fact, evidence suggests that -ing wasn’t even heard as the correct form. Many elocution guides from the 18th century provide rhyming word pairs like “herring/heron,” “coughing/coffin” and “jerking/jerkin,” which suggest that “-in” may have been the preferred pronunciation of words ending with “-ing.” Even writer and satirist Jonathan Swift – a frequent lobbyist for “proper” English – rhymes “brewing” with “ruin” in his 1731 poem “Verses on the Death of Dr. Swift, D.S.P.D..”

Embrace the change

Language has always shifted and evolved. People often bristle at changes from what they’ve known to what is new. And maybe that’s because this process often begins with speakers that society usually looks less favorably on: the young, the female, the poor, the nonwhite.

But it’s important to remember that being disliked and bad are not the same thing – that today’s speech pariahs are driven by the same linguistic and social needs as the Londoners who started going with “does” instead of “doth” or dropped the “t” in often.

So if you think the speech that comes from your lips is the “correct” version, think again. Thou, like every other English speaker, art literally the product of centuries of linguistic reinvention.

The Conversation

Valerie M. Fridland 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. Despite all the likes, literallys and dropped g’s, English isn’t decaying before our eyes – https://theconversation.com/despite-all-the-likes-literallys-and-dropped-gs-english-isnt-decaying-before-our-eyes-279955

Placebo effect can work as well as real medicine – but your body may need permission to use it

Source: The Conversation – USA (3) – By Phil Starks, Associate Professor of Biology, Tufts University

From empty pills to homeopathy to sham surgery, placebos have powerful effects on the body. Irina Marwan/Moment via Getty Images

The first time the placebo effect really got under my skin was when I read that roughly one-third of people with irritable bowel syndrome improve on placebo treatments alone. Usually this statistic is presented as a fascinating quirk of medicine. My reaction was anger.

Humanity possesses an extremely effective treatment, with essentially zero side effects – and patients need someone else’s permission to use it.

The placebo effect refers to the improvements in symptoms that patients experience after they’re given an inert treatment like a sugar pill. Driven by expectation, context and social cues rather than pharmacology, the placebo effect is often dismissed as all in the mind. But decades of research have shown it is anything but imaginary.

Placebo treatments can trigger measurable changes in the brain, immune system and hormone function. In studies on pain, placebos cause the brain to release endorphins, the body’s natural opioids. In Parkinson’s disease, placebo injections increase dopamine activity in the brain. The placebo effect isn’t magic. It’s biology.

Having spent nearly a quarter-century teaching evolutionary medicine, I’ve come to see placebos not as curiosities of clinical trials but as windows into how human biology responds to social signals. And it’s that relationship that is exactly what makes the placebo effect unsettling.

Medicine works, even when it isn’t medicine

The placebo effect is so reliable that researchers must account for it in nearly every clinical trial.

When testing a new drug, scientists compare its effects to what patients experience on a placebo treatment like sugar pills, saline injections or sham surgery. If the drug doesn’t outperform the placebo, it rarely reaches the public. Placebo responses are common and powerful enough to rival active treatments.

Even surgery isn’t immune to the placebo effect. In several well-documented studies of knee procedures, patients who received sham operations – incisions without the full surgical repair – improved almost as much as those who received the real procedure.

Clinician in scrubs and gloves holding wrist of patient lying on a hospital bed
The experience of going under the knife can itself be healing.
Jacob Wackerhausen/iStock via Getty Images Plus

Clearly something real is happening inside the body. But the strangest part of the placebo effect is not that it works. It’s what makes it work.

The prescription of belief

Placebo treatments tend to be more effective when delivered by credible authorities. Pills work better when prescribed by doctors wearing white coats. Expensive pills outperform cheap ones. Injections produce stronger responses than tablets.

Some researchers have even removed the deception from placebo experiments entirely. In open-label placebo studies, patients are directly told they are receiving a placebo; and yet many still report significant improvement.

But look more closely at how these studies are run. Patients are not simply handed a sugar pill and sent home. They receive an explanation from a clinician, in a medical setting, within a structured ritual of care: a context that may be doing much of the biological work.

Even when the deception disappears, the social scaffolding remains. The permission to heal is still being granted by someone else.

The placebo effect extends beyond the patient

The placebo effect is often framed as something happening inside an individual. But it does not operate in isolation.

Consider what happens in veterinary medicine. Dogs and cats cannot believe a treatment they’re given will work; they have no concept of receiving medication. Yet when owners and vets believe an animal is being treated, they consistently report improvements in pain and mobility that medical tests do not confirm.

In one study of dogs with osteoarthritis, owners reported improvement roughly 57% of the time for animals receiving only a placebo.

Dog resting head against person's arm while vet inspects a front leg
Is Fido feeling better, or is the placebo effect working on you?
Chalabala/iStock via Getty Images Plus

The animals themselves may not have improved. But the humans caring for them perceived they had. The healing signal, it turns out, travels through the humans in the room.

When healing makes things worse

There have been times when going to the doctor made you less likely to survive. In the 19th century, mainstream medicine was built on bloodletting, purging and doses of mercury and arsenic – treatments that killed as often as they cured.

Homeopathy emerged in the late 18th century precisely in this context. Its founder, Samuel Hahnemann, was a physician horrified by the harm the conventional medicine of his time was causing. His highly diluted versions of contemporary remedies did nothing pharmacologically. But they also did not kill people, which put them decisively ahead of the competition.

Homeopathic patients not only survived but also reported dramatic recoveries from chronic ailments and acute infections alike. During the cholera epidemics of the mid-1800s, patients at homeopathic hospitals had lower death rates than those receiving standard care. Why was that?

The standard cholera treatment of the era was aggressive and exhausting; for a disease that already caused massive fluid loss, doctors often prescribed further bloodletting, along with toxic purgatives such as calomel – a form of mercury – to “flush” the system. In contrast, homeopathic care involved extreme dilutions of substances in water or alcohol, effectively providing hydration and a calm, structured environment without the physiological assault.

Death rates were lower not because homeopathy worked but because the placebo effect – combined with not poisoning patients – was more effective than the medicine of the day.

One principle of homeopathy posits that diluting a drug enhances its effects.

Healing is not free

The body needs resources to heal from injury and disease. Activating systems such as immune responses, tissue repair and inflammation at the wrong time can be dangerous.

A full-scale immune response is metabolically expensive, with fever increasing metabolic rate by roughly 10% per degree Celsius rise in body temperature. Triggered at the wrong time, this can deplete critical energy reserves needed for immediate survival, such as escaping a predator. Furthermore, misplaced or overzealous inflammation causes collateral damage to healthy tissues, potentially leading to chronic dysfunction.

Some researchers have proposed that placebo responses reflect a kind of biological health governor: a system that regulates when the body invests heavily in recovery. Cues from trusted individuals may be exactly the signal the body waits for before committing resources to recovery. A caregiver’s reassurance, a physician’s authority and the rituals of medicine may tell the body that conditions are finally stable enough to devote energy to healing.

If that interpretation is correct, the placebo effect is not a trick of the mind. It is an ancient biological system responding to social information.

Body under stress

The placebo effect resembles another system people struggle with today: the stress response.

Stress evolved to keep you alive in the face of acute danger – predators, famine, immediate physical threat. These days, this useful piece of biological engineering might fire when someone hasn’t replied to your email. The system that once saved people’s lives now makes many miserable over things that would have been unimaginable to their ancestors.

You can talk back to the stress response, consciously reappraising the threat – in other words, reframing a looming deadline not as a catastrophe but as a manageable challenge – to help quiet it. But notice what you cannot do: You cannot simply decide to activate your placebo response. You cannot will yourself to release pain-relieving endorphins by believing hard enough in a sugar pill. For that, you still need the ritual, the white coat, the authority figure. You need someone else.

The stress response, misfiring as it is, remains yours. The placebo response has been outsourced: not because it wasn’t always social, but because even now, people still can’t seem to access it on their own.

The uncomfortable implication

The placebo effect is not a trick of the mind. It is a feature of human biology that people have largely surrendered to whoever performs authority most convincingly.

If belief can activate biological healing pathways, belief can also be manipulated. Charismatic figures, elaborate medical rituals and expensive treatments may produce real improvement in symptoms even when the underlying treatment is physiologically inert. That is how wellness culture works. It leverages the same social scaffolding of care to trigger the body’s internal pharmacy, regardless of whether the treatment itself does anything.

The placebo effect is often celebrated as proof that the mind can heal the body. But I believe that may not be its most interesting lesson. It also reveals that human physiology evolved to take its cues from other people. Your brain, immune system and pain response are not isolated machines. They are deeply intertwined with social signals, expectations and trust.

In a world filled with doctors, advertisements, wellness influencers and elaborate medical rituals, that insight is both fascinating and profoundly maddening. People are walking around with one of the most powerful healing systems ever documented locked inside them, and they can reliably access it only when someone in a position of authority gives them permission.

The Conversation

Phil Starks 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. Placebo effect can work as well as real medicine – but your body may need permission to use it – https://theconversation.com/placebo-effect-can-work-as-well-as-real-medicine-but-your-body-may-need-permission-to-use-it-279923

Attending multiple places of worship is the norm for many Americans

Source: The Conversation – USA (3) – By Katie E. Corcoran, Professor of Sociology, West Virginia University

Many of the Americans who go to more than one congregation do so to experience a different worship style or because friends attend. Rawpixel/iStock via Getty Images Plus

Most U.S. adults who attend religious services attend multiple congregations, at least occasionally, according to our new research.

As sociologists who research congregational life in the United States, we fielded a nationally representative survey in 2023. We asked over 2,000 adults across many religious affiliations, and those with no religion, a variety of questions about their religious beliefs and activities.

Our analysis, which was published in the Review of Religious Research, found that roughly 12% of all adults who attend services go to multiple congregations “regularly” and 45% attend multiple congregations “occasionally.” Of those who attend multiple congregations, 73% attend two congregations and 27% attend three or more, at least occasionally.

Adults who attend multiple congregations are more likely to be politically liberal, whereas political conservatives are more likely to always attend one congregation. We also found that evangelical Protestants are less likely to attend multiple places of worship than Catholics. About 17% of those attending a single place of worship identified as evangelical Protestant, versus only 10% of people who attended more than one.

Catholics, on the other hand, are more likely to attend multiple congregations. Unsurprisingly, so are people who identify with multiple religious traditions.

Why attend multiple places of worship? Of those who do, 24% said it’s to experience a “different style of service,” and another 24% said “I have friends that attend.” Another common reason was to attend special events at another congregation.

Americans who attend multiple congregations generally give less time and money to each congregation they attend. Cumulatively, however – across all the congregations they attend – they donate and volunteer at similar levels to people who always attend the same house of worship.

Why it matters

Historians and social scientists sometimes refer to religion in the U.S. as a “marketplace” in which different places of worship compete for members. That theory assumes that when people begin attending a new place of worship, they stop attending their old one – that their loyalties are exclusive.

Instead, our research shows that many individuals across regions and religions take a more flexible approach. They might attend one place because they appreciate its worship style, but they also attend another to hang out with a particular friend group.

For researchers, this complicates how we measure and track changes in American religion. Many surveys, for example, ask people only a single question about how often they attend religious services. How do people who attend multiple congregations respond? Do they only report how often they attend their most frequent place of worship, try to add up across the different congregations they attend, or something else?

If surveys are not asking about multiple attendance, then they are likely missing pieces of the puzzle.

What’s next

Our survey results suggest that researchers need to move away from thinking about congregational attendance as exclusive.

While our survey focused on the characteristics and behaviors of individuals, we would like to see future surveys examine what types of congregations are more likely to have exclusive versus nonexclusive attenders. Similarly, our research did not distinguish between in-person versus virtual service attendance, which could provide additional insights into why people attend multiple congregations.

The Research Brief is a short take on interesting academic work.

The Conversation

Katie E. Corcoran receives funding from the National Science Foundation, the John Templeton Foundation, and the Patient-Centered Outcomes Research Institute. This article was made possible through the support of Grant 62630 from the John Templeton Foundation. The opinions expressed in this publication are those of the author(s) and do not necessarily reflect the views of the John Templeton Foundation.

Christopher P. Scheitle receives funding from the National Science Foundation and the John Templeton Foundation. This article was made possible through the support of Grant 62630 from the John Templeton Foundation. The opinions expressed in this publication are those of the author(s) and do not necessarily reflect the views of the John Templeton Foundation.

ref. Attending multiple places of worship is the norm for many Americans – https://theconversation.com/attending-multiple-places-of-worship-is-the-norm-for-many-americans-277484

Why understanding autism means looking beyond spoken language – two autistic researchers of communication explain

Source: The Conversation – UK – By Lou Harvey, Associate Professor of Education, University of Leeds

The idea of the “autism spectrum” is widely used in diagnosis, education and public discussion. First developed by the psychiatrist Lorna Wing in the 1980s, the term was intended to reflect the wide range of autistic experiences and needs.

But a growing body of research is questioning whether the concept still helps us understand autistic lives.

We are autistic researchers of communication, education and neurodiversity. Our research focuses on paying attention to how people express knowledge and experience when communication does not fit mainstream expectations, particularly when it goes beyond spoken language.

Across this work, one finding is consistent: both autistic and non-autistic people communicate meaningfully in various ways. But this variety is often overlooked or misunderstood by traditional models of autism.

These models tend to come from cognitive science and clinical practice, where autism is defined primarily as a communication “disorder”. They suggest that autistic people have difficulty speaking, maintaining eye contact, or engaging in back-and-forth conversation.

Diagnosis is typically based on external observation by doctors, rather than on autistic people’s own accounts of their experience.

When different perspectives are dismissed

Critics argue that this approach reflects what is known as “neuronormativity”. This is the belief that there is a standard or “normal” way to communicate, think and behave. It is rooted in an assumption that language, especially speech, is what makes us fully human. Therefore, when people communicate differently, their knowledge can be treated as less valid or harder to access.

Autistic scholar M. Remi Yergeau has argued that autism has often been framed as a “narrative condition” by cognitive scientists. In other words, it is assumed that autistic people are unable to express meaningful self-knowledge.

If someone’s way of communicating is already judged incoherent or unintelligible, their perspective can easily be dismissed. This means autistic people are not considered to be reliable sources of knowledge about their own lives.

Our research, and that of other autistic scholars, challenges this assumption.

Communication is more than words

There is increasing evidence that autistic people express themselves in a wide range of ways that are not always recognised as communication. Chris’s research, for example, shows how autistic people often communicate through deep engagement with particular interests. These interests can be a way of expressing identity, connection and meaning, rather than simply being a “symptom”.

Many autistic people also use rhythmic or repeated movement and sound – often referred to as “stimming” – or repetition of words and phrases, known as echolalia. These forms of expression can communicate comfort, distress, humour, joy or focus. They can also provide sensory regulation or pleasure. They may not fit conventional ideas of language, but they are meaningful.

However, because of the deeply ingrained belief that “real” communication must be verbal, these forms of expression have received little attention within mainstream science. Yet they point to something important: communication and knowledge are not just about words. They are also about feeling, and the things we cannot say.




Read more:
What autistic people – and those with ADHD and dyslexia – really think about the word ‘neurodiversity’


Research by the neuroscientist Antonio Damasio has shown that emotion is not separate from thinking but fundamental to it. Feelings shape attention, decision-making and understanding. In this sense, feeling is part of how we know the world. If we are to take people’s knowledge about themselves seriously, we must pay attention to it.

Our research builds on this idea, showing that communication and knowledge are not limited to what can be clearly spoken or measured.

Aerial view of crowd people connected by lines
Language has limits.
Master1305/Shutterstock

From diagnosis to paying attention

Clinical diagnosis remains necessary because it enables access to support and services. But diagnosis alone may not fully capture how autistic people experience and communicate their needs.

We suggest a shift in emphasis. Rather than asking, “What is wrong with this person?” we may ask, “How can we pay attention to this person?”

Paying attention means taking feeling seriously as a way of knowing and recognising that language has limits. Research by Lou and colleagues has found that when spoken language is not available or not sufficient, other forms of interaction – such as art, play, care and simply being with others – can become more meaningful. These forms of communication are often harder to observe or measure than language, which may explain why they have received less attention in traditional research.

But they are fundamental to how many people, autistic or not, experience connection and understanding. Recognising this has practical implications. It means that decisions about education, support and policy are shaped by how autistic people actually experience the world.

In schools, this could lead to better identification of barriers and more responsive teaching practices. In policy, it could inform more effective approaches to special educational needs provision, diagnosis and employment support.

More broadly, it suggests that expanding how we understand communication could benefit everyone. All of us – regardless of whether we are autistic – have experiences that are difficult to express in words.




Read more:
Why it’s time to rethink the notion of an autism ‘spectrum’


The concept of the autism spectrum was originally intended to reflect diversity. But if it continues to rely on narrow assumptions about communication and knowledge, it may not fully capture that diversity in practice. Our work is part of a growing area of research exploring how to better recognise different forms of expression and understanding, including those that fall outside conventional definitions of language.

Taking these forms seriously does not mean abandoning science. It means broadening what we consider to be valid evidence, and who we recognise as knowledgeable about autistic experience. If we do this, we may find that approaches designed to support autistic people can support many others too.

The Conversation

Lou Harvey has received funding from the UK Arts and Humanities Research Council, the former Higher Education Funding Council for England, and the Society for Research into Higher Education.

Chris Bailey received academic funding from the UK Literacy Association (UKLA) to to total of £1400 for the Ruling Passions project that is mentioned in this article.

ref. Why understanding autism means looking beyond spoken language – two autistic researchers of communication explain – https://theconversation.com/why-understanding-autism-means-looking-beyond-spoken-language-two-autistic-researchers-of-communication-explain-278633

How school grades can affect mental health – particularly for girls

Source: The Conversation – UK – By Anna Linder, Researcher in Health Economics, Lund University

LightField Studios/Shutterstock

Schools increasingly rely on testing, grading and performance accountability. In England, Ofsted inspections and school league tables sharpen the focus on measurable performance. Similar developments have taken place in Sweden, where repeated reforms have introduced earlier and more detailed assessments.

Performance-driven school environments shape young people’s wellbeing. Yet despite frequent reforms to evaluation systems, their psychological consequences rarely take centre stage in policy debates.

Our new study connects these trends with rising youth mental health issues. Our research shows that earlier and more formal grading can increase clinically diagnosed mental health problems, particularly among girls.

Our research examined a Swedish reform introduced in 2012 that moved the start of formal grading from grade eight (around age 14) to grade six (around age 12). This meant official grades and clearer signals of relative performance arrived two years earlier than before.

To estimate the effects, we compared children born just before and just after the reform cut-off. Because exposure depended strictly on date of birth, students on either side were similar in background but differed in whether they received earlier grades. We also accounted for certain underlying trends across this time period, such as an overall increase in mental health diagnoses over time. Comparing cohorts in this way allows us to isolate whether earlier grading itself led to changes in mental health diagnoses.

Our analysis draws on nationwide linked education and health registers covering more than 520,000 children born between July 1992 and June 2000. We examined psychiatric diagnoses recorded in outpatient and inpatient care during the year students entered grade nine (the end of lower-secondary school).

Earlier grades affect girls’ mental health

Earlier grading increased diagnoses of depression and anxiety among girls, with the largest effects among girls whose academic achievement ranged from low to average. Effects for boys were smaller and less consistent.

Among girls, the share diagnosed with depression or anxiety increased from 1.4% to 2.0%. While the absolute change (0.6 percentage points) may appear modest, psychiatric diagnoses at this age are relatively uncommon. The change represents roughly a two-fifths increase compared with before the reform.

A young teen girl with her face in her hands being comforted by adults
Depression and anxiety were shown to be more common in girls who received grades at earlier ages.
SeventyFour/Shutterstock

Our findings point to academic pressure and social comparison as likely reasons for this increase in mental health problems. Formal grades make performance more visible at a younger age, clearly signalling how a child ranks among their peers. At a stage when young people’s understanding of themselves is still developing, this may heighten their sensitivity to comparison and perceived failure.

One plausible explanation is greater sensitivity to performance feedback among girls. In earlier research, we found that when girls received grades more favourable than their measured performance would predict, their mental health improved. This suggests they may be particularly responsive to evaluative feedback, and therefore more vulnerable when grading intensifies.

Wider consequences

Our findings indicate that academic pressure may contribute to gender gaps in adolescent mental health. If girls are more likely to internalise the pressure and stress of academic evaluation, earlier grading may unintentionally widen the well-documented existing gender disparities in mental health.




Read more:
Making sense of the widening gender mental health gap: what teenage girls told us


We do not argue that grading is inherently harmful. Grades can motivate, guide learning and inform parents and teachers. But timing and design matter. When evaluation becomes more formal earlier in schooling, unintended psychological costs can emerge alongside academic goals.

As grading systems continue to evolve, questions of timing and intensity deserve careful thought. Schools are not only institutions for measuring performance, but environments where young people form their identities. Designing education systems that support both learning and healthy development requires taking both aims seriously.

Education policy inevitably involves trade-offs. Systems designed to measure and raise standards also shape students’ daily experience. Our findings suggest that when policymakers move formal evaluation to younger ages, they should weigh mental health impacts alongside academic benefits.

Accountability policies should consider psychological effects. This does not mean abandoning grading, but evaluation systems should be sensitive to the development stage of students and accompanied by relevant support that helps students interpret feedback constructively.

Students respond differently to evaluation. Reforms that work well for some may create strain for others, particularly those already vulnerable to performance pressure. Monitoring wellbeing alongside academic outcomes can help identify unintended consequences early.

The Conversation

Anna Linder receives funding from the Swedish Research Council for Health, Working Life and Welfare and the Public Health Agency of Sweden.

Gawain Heckley currently receives funding from Swedish Research Council , Swedish Research Council for Health, Working Life and Welfare and Jan Wallanders och Tom Hedelius stiftelse.

Ulf Gerdtham receives funding from Swedish Council for Working Life and Social Research.

ref. How school grades can affect mental health – particularly for girls – https://theconversation.com/how-school-grades-can-affect-mental-health-particularly-for-girls-277907

Alzheimer’s drugs offer little benefit, major review finds – and the reasons go deeper than the science

Source: The Conversation – UK – By Simon Kolstoe, Associate Professor of Bioethics, University of Portsmouth

PeopleImages/Shutterstock.com

How is it possible to spend tens of billions of dollars developing drugs to treat a serious disease that affects millions of people, and yet end up with something that does not work? This is a mystery that has bedevilled Alzheimer’s research for years.

A new review of the evidence has concluded that the leading class of Alzheimer’s drugs “probably result in little to no difference” in a range of measures, including reducing dementia severity. This finding was quickly used to further justify the NHS’s decision two years ago not to fund these drugs.

These findings are disappointing, not just for researchers and drug companies, but also for the tens of millions of people and their families suffering from the effects of a devastating disease.

Medical research is often reported through success stories, but Alzheimer’s disease has remained stubbornly resistant to the development of life-changing breakthroughs. This has not gone unnoticed. A couple of years ago, investigative journalists uncovered significant fraud in important studies underpinning some of the science behind the leading Alzheimer’s drugs.

While this fraud is not solely responsible for the lack of progress in Alzheimer’s research, it does reveal how vested interests can distort science and how commercial interests can sometimes override indications that a specific approach may not actually be working. It also reveals how social, political and economic factors can distort and hold back entire fields of research.

A century of science and still no answers

The German psychiatrist Alois Alzheimer first identified the disease that bears his name in 1906. Over the subsequent years, it was found to be characterised by abnormal protein deposits in the brain called amyloid “plaques” and similarly misfolded protein tau tangles.

As these misfolded proteins are not found in healthy brains, it was assumed that they were the cause of the disease. But subsequent studies showed that the amounts of these protein deposits did not correlate well with disease severity, unlike similar diseases, where misfolded protein deposits occurring in other parts of the body led directly to organ failure.

This complex relationship between the pathological changes in the brains of people with Alzheimer’s and the psychological progression of the disease has split the research field for many years.

At one point, those proposing that amyloid deposits (or at least the molecular processes leading to them) were the main cause of the disease were even referred to as “Baptists”, while those holding tau as responsible were called the “Tauists”. Although these have been the main two theories as to the cause of the disease, there have been numerous others, such as linking the disease to the abnormal behaviour of neurotransmitters, inflammation, presence of pollutants, age-related changes, DNA damage, viruses and even sleep disturbance.

In situations like this, when there are many competing theories, researchers who start working on one theory can start to become entrenched. This is an unfortunate byproduct of competitive funding models, where research money tends to flow to the researchers who are most successful at arguing that their approach is the most promising and therefore worthy of receiving more research money. This is an interesting example of how science is not always an entirely objective endeavour.

An illustration of amyloid plaques clogging up a brain's neurons.
Amyloid plaques (in orange) are a hallmark of Alzheimer’s. But are they the cause?
Kateryna Kon/Shutterstock.com

This pressure on researchers to publish papers and attract funding is probably a contributing factor to the significant fraud linked specifically to some working on the amyloid hypothesis for Alzheimer’s. In one case, a researcher in the US was forced to resign from his university following the retraction of a much-cited paper, and the discovery that over 20 other papers may have similarly questionable data.

In a separate case, an academic faced fraud charges, while a pharmaceutical company they worked with came under investigation for allegedly misleading investors. Both of these cases were in connection with a different approach to treating Alzheimer’s, namely, targeting a protein called filamin A.

Indeed, controversies within Alzheimer’s research have become so frequent that they have inspired an entire book dedicated to examining the issue.

Matthew Schrag, a neuroscientist who played a key role in exposing elements of fraud in Alzheimer’s research, said: “You can cheat to get a paper. You can cheat to get a degree. You can cheat to get a grant. You can’t cheat to cure a disease. Biology doesn’t care.”

While scientific breakthroughs undoubtedly underpin much of modern life, the example of Alzheimer’s research serves as a reminder that the path from defining a problem to discovering a solution is rarely straightforward.

It would be nice to think that the main incentive for most researchers might be solving a problem or curing a disease, but the actual situation is far more complex. Research relies on funding, and researchers get jobs based on reputation, often in the form of publications. Because of this, the wrong behaviour can become incentivised.

The complexity of Alzheimer’s disease and the lack of obvious answers or cures make this field particularly susceptible to distortion by the social factors that can influence science.

As researchers and pharmaceutical companies compete for funding and investment, the science starts to get lost behind the games that are played. The end result is not only financial loss and lack of progress, but in the case of this devastating disease, millions of people also end up suffering through a lack of effective treatments.

The Conversation

Prior to moving into Bioethics Simon Kolstoe spent 17 years working on protein folding diseases (including Alzheimer’s) on grants funded by the MRC, BBSRC, Wellcome Trust and with a number of pharmaceutical companies. He receives no income from his former research in this area.

ref. Alzheimer’s drugs offer little benefit, major review finds – and the reasons go deeper than the science – https://theconversation.com/alzheimers-drugs-offer-little-benefit-major-review-finds-and-the-reasons-go-deeper-than-the-science-280833

L’IA générative ne détruira pas votre emploi mais elle va changer profondément votre métier

Source: The Conversation – France (in French) – By Hugo Spring-Ragain, Doctorant en économie / économie mathématique, Centre d’études diplomatiques et stratégiques (CEDS)

L’intelligence artificielle ne détruit pas tant des emplois qu’elle modifie profondément les compétences nécessaires pour les accomplir. De cette confusion entre emploi et compétences risquent de naître des erreurs dans les politiques d’accompagnement des mutations en cours.


Chaque grande vague technologique a produit son lot de prédictions contradictoires sur l’emploi. L’intelligence artificielle (IA) ne fait pas exception. Mais avant de savoir combien d’emplois l’IA va créer ou détruire, il faudrait s’accorder sur ce qu’elle automatise réellement. La réponse oblige à distinguer trois notions que le débat public confond régulièrement : l’emploi, la compétence et la tâche.

Les grandes vagues d’automatisation ont suivi une logique remarquablement stable en deux siècles : vapeur, électricité, robotique industrielle ont déplacé les tâches physiques répétitives et épargné le travail cognitif non routinier. Cette régularité empirique a été formalisée par Autor, Levy et Murnane dès 2003 sous le nom d’« hypothèse de polarisation des tâches ».

Une illusion persistante

L’automatisation ronge les emplois intermédiaires, ceux des cols bleus qualifiés et employés de bureau exécutant des tâches routinières, mais épargne les deux extrémités. D’un côté, les tâches manuelles non routinières, comme la plomberie ou les soins, de l’autre, les tâches cognitives non routinières, comme l’analyse, le conseil ou la rédaction experte. Ces dernières constituaient le cœur des professions du tertiaire qualifié, et la conviction s’était solidement installée qu’elles resteraient hors d’atteinte.




À lire aussi :
Pourquoi l’IA oblige les entreprises à repenser la valeur du travail


Cette conviction reposait sur une confusion conceptuelle qu’il faut dissiper avant tout. Ce n’est pas l’emploi de juriste ou d’analyste financier qui était protégé, c’est un ensemble de tâches précises qui composaient cet emploi et qui résistaient jusqu’ici à l’automatisation. La distinction entre ces trois niveaux est fondamentale.

Un emploi désigne un poste occupé dans une organisation, avec un contrat, un salaire, une fiche de poste. Une compétence est une capacité cognitive ou technique mobilisable dans plusieurs contextes professionnels. Une tâche est une action précise, délimitable, dont on peut évaluer si elle est ou non automatisable à un coût donné. C’est à ce troisième niveau que se joue réellement la transformation en cours, et c’est précisément ce niveau que le débat public ignore.

Rupture dans la longue histoire du capitalisme industriel

L’IA générative constitue une rupture dans cette longue histoire. Pour la première fois depuis l’industrialisation, les tâches cognitives qualifiées, rédaction, analyse documentaire, synthèse, production de premiers jets, se retrouvent directement exposées. Eloundou, Manning, Mishkin et Rock estiment qu’environ 80 % de la population active états-unienne pourrait voir au moins 10 % de ses tâches affectées par les grands modèles de langage, et que cette exposition croît avec le niveau de salaire. C’est l’exact inverse du schéma observé lors de toutes les vagues précédentes.

Le cadre analytique développé par Acemoglu et Restrepo permet d’aller plus loin. Leur modèle distingue deux effets opposés produits par toute vague d’automatisation :

  • l’effet de déplacement, d’abord : des travailleurs perdent des tâches au bénéfice de la machine, ce qui réduit mécaniquement la demande de travail et pèse sur les salaires des groupes affectés ;

  • l’effet de réintégration, ensuite : l’automatisation produit de nouvelles tâches où la valeur humaine est décisive, générant une demande compensatrice.

L’histoire longue du capitalisme industriel peut se lire comme une succession de ces deux effets, le second finissant généralement par compenser le premier.

Le cas de la traduction permet de voir très concrètement comment déplacement et réintégration se combinent, l’IA générative peut produire en quelques secondes un premier jet dans une autre langue, ce qui déplace une partie du travail auparavant effectué par des traducteurs humains vers la machine. Mais cette automatisation réintègre simultanément d’autres tâches ou renforce leur importance, telles que la vérification des contresens, l’adaptation au contexte culturel, l’harmonisation de la terminologie, le contrôle de la qualité et la validation finale.

Potentiel déséquilibre

Ce qui est préoccupant avec l’IA générative, c’est le déséquilibre potentiel entre ces deux dynamiques. Le déplacement s’opère à une vitesse que les marchés du travail et les institutions de formation peinent à absorber, tandis que la réintégration reste encore largement à construire.

Cependant, le phénomène le plus important n’est pas sectoriel, mais il est interne aux métiers eux-mêmes. Dans ses « Perspectives de l’emploi », l’OCDE met en évidence que les professions les plus exposées à l’IA générative sont précisément celles à forte densité cognitive : finance, droit, conseil, enseignement supérieur. Contrairement aux vagues précédentes qui frappaient les zones rurales et les bassins industriels, l’exposition est désormais plus forte dans les grandes métropoles et chez les travailleurs hautement qualifiés, un renversement géographique et social inédit.

Redistribuer les tâches

Ce renversement se joue concrètement au niveau de la tâche.

Dans un même poste d’analyste financier ou de juriste, certaines tâches migrent vers l’IA (produire un résumé exécutif, générer une première analyse de contrat, synthétiser une revue de littérature), tandis que d’autres se revalorisent mécaniquement : définir le cadre d’analyse pertinent, évaluer la qualité d’un raisonnement automatisé, détecter une erreur factuelle dans un output, assumer la responsabilité juridique ou éthique d’une décision. Ce ne sont pas des emplois qui disparaissent. Ce sont des bouquets de tâches qui se redistribuent entre humains et machines, transformant de l’intérieur ce qu’un employeur attend d’un salarié qualifié.

Cette redistribution des tâches a une implication directe sur les compétences qui seront réellement valorisées dans les années à venir, et elle renverse une partie des évidences habituelles sur la formation professionnelle.

Former les travailleurs à utiliser l’IA au sens instrumental, maîtriser un outil, rédiger des prompts efficaces, s’approprier une interface, est utile à court terme, mais c’est insuffisant si la compétence réellement demandée demain n’est pas de produire avec l’IA, mais de superviser et de critiquer ce qu’elle produit.

Un enjeu de formation

Or, superviser efficacement un output d’IA requiert exactement ce que les formations courtes et techniques peinent à développer : une culture générale solide permettant de détecter une erreur de fond, une capacité argumentative pour évaluer la cohérence d’un raisonnement, une connaissance des biais cognitifs pour identifier les angles morts d’une analyse automatisée. Ce sont des compétences que les sciences de l’éducation regroupent sous le terme de métacompétences : apprendre à apprendre, à exercer un jugement critique, à mobiliser des savoirs dans des situations inédites.

Arte, 2025.

Le paradoxe devient alors le suivant. À mesure que l’IA automatise les tâches routinières de la connaissance, elle valorise précisément ce que les formations généralistes et les cursus de sciences humaines cultivent de longue date et que les débats sur l’employabilité ont eu tendance à déconsidérer au profit de compétences techniques plus immédiatement mesurables.

Non par nostalgie des humanités, mais par logique économique pure. Si la machine produit le texte, l’analyse et la synthèse, la valeur marginale de l’humain réside dans sa capacité à juger si ce texte dit vrai, si cette analyse est pertinente au regard du contexte réel, si cette synthèse sert l’objectif poursuivi.

The Conversation

Hugo Spring-Ragain 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. L’IA générative ne détruira pas votre emploi mais elle va changer profondément votre métier – https://theconversation.com/lia-generative-ne-detruira-pas-votre-emploi-mais-elle-va-changer-profondement-votre-metier-279911

Apple chief executive Tim Cook resigns after 15 years. What’s next for the tech giant?

Source: The Conversation – Global Perspectives – By Rajat Roy, Associate Professor, Bond Business School, Bond University

Today, Apple announced the tech company’s longtime chief executive Tim Cook will step down and transition to the role of executive chairman of Apple’s board of directors.

This change will take effect from September 1 2026. John Ternus, currently Apple’s senior vice president of hardware engineering, will take over as chief executive.

However, Cook will remain in place until then to ensure a “smooth takeover”. As chairman, he’ll then take on a more strategic role of engaging with policy makers and corporate governance.

Ternus is a 25-year-veteran at Apple. He is widely seen as an internal replacement shaped by long-term succession planning. His appointment marks Apple’s first leadership transition since Cook took over from Steve Jobs in 2011.

Rather than signalling a dramatic shift, this transition is likely going to be more subtle, without a major strategic reset.

A rich legacy for Cook

Cook was only the second chief executive in Apple’s history, after cofounder Steve Jobs resigned in 2011 and died six weeks later.

Cook is widely recognised for his strengths in operations, scale and business model innovation. Under his leadership, Apple became one of the most successful global supply chain organisations reaching more than 200 markets worldwide. The company’s value grew from about US$350 billion in 2011 to US$4 trillion today.

Importantly, Cook drove a decisive shift towards service monetisation – charging users fees for Apple’s digital services and subscriptions, rather than just making money from selling devices such as iPhones, iPads and laptops. Cook’s strategy capitalised on Apple’s already massive base of 2.5 billion active devices.

Service monetisation led to high-margin revenues from Apple’s offerings such as iCloud, Apple Music and the Apple store. Consequently, Apple made more than US$100 billion in 2025 from this business, providing a stable and predictable income beyond cyclical hardware sales.

Who is John Ternus?

In contrast to Cook, Ternus has a deeply technical, product-oriented background shaped by more than two decades in hardware engineering.

At Apple, he has overseen the development of key product lines that include many iterations of the iPhone, iPad, AirPods and the Apple Watch, among others. He’s been closely associated with advances in materials, durability and performance.

Ternus spearheaded the recent introduction of the relatively affordable MacBook Neo and the radically thin yet durable iPhone Air. He also led the way on incorporating an unprecedented active noise cancellation feature into AirPods, which the company described as “world’s best”.

The difference in background between Cook and Ternus suggests a subtle but important shift in emphasis for the technology giant.

While Cook focused on transforming Apple into a highly monetised ecosystem anchored in services and global scale, Ternus is likely to reassert the importance of product-led innovation. In his current role, he’s been focusing on engineering excellence and integrating fresh technologies into Apple devices.

With Ternus at the helm, it’s likely the company will try to balance an optimised ecosystem of revenue (that is, service monetisation) with reinvigorating the hardware products that sustain it. That would make a lot of sense.

Apple faces numerous pressures

A stronger product focus under Ternus may also become the company’s response to multiple structural pressures facing Apple.

In the Cook era, Apple was often criticised for incremental innovation, in contrast to Jobs’ visionary leadership that was credited with changing modern consumer tech.

Major competitors Google and Microsoft are making rapid advances in cloud-based artificial intelligence (AI), with Apple seemingly lagging behind (although some experts say not investing as heavily in AI could be a worthwhile response to the AI hype bubble).

Apple’s device-centric approach will ensure products are meaningfully distinct from competitors through partnerships. For example, the company will be using Google’s Gemini AI as the basis for an enhanced Siri assistant. At the same time, consumers are upgrading their devices more slowly, so Apple will need more compelling product innovation to drive demand.

The company is also vulnerable to global supply chain disruption due to geopolitical tensions. This can negatively impact Apple’s timelines of product delivery, and even lead to lower-quality products if suppliers can’t fulfil Apple’s expectations. In recent years, Apple has already been addressing this by moving some of its manufacturing from China to Vietnam.

Time will tell, but so far everything suggests Ternus succeeding Cook as Apple chief executive will represent a logical and necessary calibration of strategy, rather than a radical shakeup.

The Conversation

Rajat Roy 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. Apple chief executive Tim Cook resigns after 15 years. What’s next for the tech giant? – https://theconversation.com/apple-chief-executive-tim-cook-resigns-after-15-years-whats-next-for-the-tech-giant-281122

Comment aider les enfants à passer de l’anxiété climatique à l’action ?

Source: The Conversation – France (in French) – By Sanae Okamoto, Senior Researcher in Behavioural Science and Psychology, United Nations University – Maastricht Economic and Social Research Institute on Innovation and Technology (UNU-MERIT), United Nations University

Les méthodes d’enseignement jouent un rôle essentiel pour aider les enfants à comprendre qu’ils peuvent agir et avoir une influence sur le monde qui les entoure. Rawpixel.com/Shutterstock

Plutôt que de se focaliser sur ce qui ne va pas, l’éducation au climat peut aider les enfants à se demander ce qu’ils peuvent faire. En cultivant leur agentivité, c’est-à-dire leur capacité à être maîtres de leur existence, et leur esprit critique, elle peut faire émerger une génération prête à agir pour un avenir plus durable.


Les enfants sont ceux qui ont le moins de prise sur l’avenir de la planète, mais ils seront aussi parmi les plus touchés par ses transformations. Ils peuvent ainsi ressentir le poids psychologique de ce que l’on appelle le « fossé de la futilité » : le sentiment que les actions individuelles n’ont guère de sens face à l’inaction plus large de la société face à la crise climatique.

Dans ce contexte, il est essentiel de favoriser une agentivité psychologique saine – c’est-à-dire la conviction que nous avons prise sur notre propre vie. Des leviers existent pour agir contre la crise climatique. Les enfants doivent être accompagnés afin qu’ils ne perdent pas espoir.

Avec notre collègue Kariũki Werũ, nous avons élaboré un guide expliquant comment les adultes peuvent soutenir le développement psychologique sain des enfants.

Notre approche reconnaît la gravité du changement climatique tout en ancrant les enfants dans l’espoir. L’objectif est de transformer les sentiments d’impuissance en sentiment d’efficacité personnelle – la conviction qu’ils peuvent agir.

À la maison

Pour protéger le bien-être émotionnel des enfants tout en abordant les réalités du climat, les adultes doivent aussi apprendre à parler du changement climatique avec les enfants. Cela suppose d’écouter les enfants, d’apprendre avec eux et d’utiliser un langage adapté à leur âge et à leur capacité de compréhension. Les écoles et les communautés pourraient également aider les parents en proposant des conseils pour mener ces conversations.

Surveiller l’activité en ligne d’un enfant peut aussi le protéger d’informations traumatisantes. Les parents peuvent mettre l’accent sur les progrès et les solutions, et aider leurs enfants à passer du temps à observer et apprécier l’évolution de la météo et de leur environnement.

En classe

Les écoles, les méthodes pédagogiques ainsi que les relations des enfants avec leurs enseignants et leurs camarades jouent un rôle central dans le développement de leur agentivité psychologique. Renforcer leur résilience face au changement climatique pourrait passer par un dépassement de l’apprentissage traditionnel fondé sur la mémorisation, au profit d’une « éducation critique au climat » adaptée à leur âge.

L’objectif est de donner aux élèves les moyens de questionner les systèmes existants et d’imaginer des transformations profondes, plutôt que de se sentir vaincus par l’ordre établi.

L’apprentissage en plein air, au contact de la nature, peut également renforcer ce développement. Il peut à la fois améliorer la santé mentale et transformer des notions abstraites liées au climat en expériences concrètes. Apprendre dehors peut favoriser des discussions plus constructives sur le climat et établir un lien direct entre les actions humaines, l’environnement et les solutions durables. Les observations sur le terrain et les projets d’enquête permettent ainsi de combler l’écart entre l’apprentissage et l’action.

Sur le Web

L’apprentissage du climat par l’intermédiaire des outils numériques constitue un puissant levier pour l’éducation contemporaine. Il offre des perspectives interactives et globales sur la crise climatique. Mais il doit être encadré afin de limiter les effets des « bulles de filtres » sur Internet – lorsque les algorithmes ne montrent aux utilisateurs que des informations correspondant à leurs intérêts passés. Ce phénomène peut isoler les enfants et les submerger de contenus répétitifs qui nuisent à leur bien-être.

Utilisés correctement, les outils numériques peuvent au contraire élargir la perspective des enfants sur les solutions face au changement climatique au-delà de leur environnement local.

En combinant les approches

Une éducation climatique efficace peut associer apprentissage numérique et expériences concrètes sur le terrain. Lorsqu’elle est accompagnée par des enseignants et des adultes qui jouent un rôle de guides – tout en laissant aux enfants l’espace nécessaire pour explorer et créer de manière autonome – ceux-ci peuvent bénéficier d’une éducation à la fois réaliste et équilibrée. Des programmes pionniers combinent déjà les sciences enseignées en classe, les outils numériques et des expérimentations en extérieur afin de transformer les idées des élèves en projets concrets au service de leur communauté.

À une échelle plus large, l’éducation au climat doit aussi combler l’écart entre responsabilité individuelle et pouvoir collectif. Le récit autour du climat devrait passer de la question « Qu’est-ce qui ne va pas ? » à « Que pouvons-nous faire ? » Ce changement peut donner aux enfants un sentiment d’agir sur le monde plutôt que de nourrir leur anxiété climatique. Les réseaux sociaux constituent un espace clé où cette évolution peut se produire.

Lorsqu’ils sont utilisés avec l’accompagnement d’adultes et une bonne éducation aux médias numériques, ces outils peuvent favoriser des dialogues constructifs et des actions fondées sur des données. Un usage modéré et positif des outils numériques peut aider les enfants à relier leur propre prise de conscience au monde qui les entoure et à encourager des actions à une échelle plus large pour réellement faire face à la crise climatique.

À terme, cela peut permettre aux enfants de partager leurs connaissances sur le changement climatique et d’inspirer des actions au sein de leur famille et de leur entourage. Ils peuvent ainsi devenir des acteurs influents à l’école et dans leur communauté.

Pour faire face à la crise climatique tout en préservant le bien-être des jeunes, il est essentiel d’aider les enfants à reconnaître leur capacité d’agir. Ils peuvent devenir des acteurs du changement, capables de lutter contre la désinformation et de développer une résilience psychologique durable.

Les écoles peuvent travailler avec les familles, les communautés et les responsables publics pour créer un environnement favorable à l’apprentissage du climat. Une telle approche pourrait combler l’écart entre les connaissances scientifiques sur le climat et les expériences vécues, en apportant le soutien émotionnel et les compétences pratiques nécessaires pour donner aux générations du climat les moyens de construire ensemble un avenir durable.

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. Comment aider les enfants à passer de l’anxiété climatique à l’action ? – https://theconversation.com/comment-aider-les-enfants-a-passer-de-lanxiete-climatique-a-laction-280294

L’alimentation de la mère pendant l’allaitement pourrait jouer un rôle clé pour la santé future de son bébé

Source: The Conversation – France in French (3) – By Ivette Caldelas, Investigadora Senior, UDIT – Universidad de Diseño, Innovación y Tecnología

À l’heure actuelle, il n’existe pas encore de recommandations cliniques fondées sur le microbiome du lait. Natalia Deriabina/Shutterstock

Des données récentes suggèrent que le bébé reçoit, par le lait maternel, un écosystème microbien, et notamment certaines bactéries bénéfiques qui s’avèrent essentielles à son développement en particulier au niveau immunitaire. Plutôt que de faire peser la responsabilité sur les seules mères, ces recherches doivent inspirer des politiques publiques pour les accompagner, au bénéfice des nourrissons.


Nous savons que le lait maternel est l’aliment idéal pour les nouveau-nés grâce à l’équilibre subtil de ses composants : il contient des micro et macronutriments, des facteurs immunitaires et de croissance, ainsi que des hormones indispensables au bon développement des nourrissons à chaque étape de leur croissance.




À lire aussi :
Le colostrum, premier lait maternel : bénéfices, méconnaissance et croyances


Cependant, des études récentes révèlent quelque chose de bien plus profond : le lait ne se contente pas de nourrir, il transmet également un écosystème vivant au bébé. Il contient des bactéries, des métabolites et des composés bioactifs qui peuvent façonner la santé du nouveau-né dès ses premiers jours de vie. Ces découvertes pourraient transformer notre compréhension de la pédiatrie moderne.

Le lait n’est pas stérile : il est biologiquement actif

Il y a encore un peu plus d’une décennie, selon l’idée dominante, le lait maternel était considéré comme un aliment stérile ; toute présence bactérienne était considérée comme une contamination. Cependant, des études de séquençage à grande échelle menées sur des échantillons de lait provenant de diverses espèces ont démontré que le lait contient des communautés microbiennes complexes. Parmi celles-ci, on peut citer les bactéries appartenant aux genres Bifidobacterium sp., Lactobacillus sp. et Streptococcus sp., qui sont étroitement liées à la colonisation saine de l’intestin néonatal.

Ce transfert bactérien intervient à un moment critique, quand le développement du système immunitaire du nouveau-né dépend en grande partie de la modulation immunitaire apportée par le lait maternel. Ce microbiote apporté par la mère joue un rôle important dans la maturation de la barrière intestinale, la régulation de l’inflammation et la programmation métabolique du nouveau-né.

En d’autres termes, le lait maternel n’apporte pas seulement des calories : il contribue également au développement du système immunitaire.

Un dialogue biologique entre l’intestin et le sein

Des données récentes mettent en évidence un phénomène fascinant, que les scientifiques ont baptisé « voie entéro-mammaire ». Grâce à ce mécanisme, certaines bactéries présentes dans l’intestin maternel seraient capables de migrer vers la glande mammaire, où les cellules immunitaires joueraient le rôle de transporteurs.




À lire aussi :
Dialogue autour du microbiote : comment la mère et le bébé communiquent à travers le lait maternel


Si cela venait à être pleinement confirmé – les résultats obtenus dans les modèles animaux et les études chez l’humain soutiennent de plus en plus cette hypothèse-, cela signifierait que le microbiome intestinal maternel serait capable d’influencer directement celui présent dans le lait maternel. Et cela soulève une question inévitable : quel rôle joue réellement l’alimentation maternelle ?

L’alimentation, modulateur du premier écosystème du bébé

Il ne fait aucun doute que la composition du microbiome intestinal est étroitement liée à l’alimentation. Plusieurs études ont démontré qu’une alimentation riche en fibres, en fruits, en légumes et en légumineuses favorise une plus grande diversité microbienne et la production d’acides gras à chaîne courte. Ces derniers favorisent la perméabilité intestinale et ont des effets anti-inflammatoires.

À l’inverse, les régimes riches en sucres raffinés ou en graisses sont associés à une moindre diversité bactérienne, à une présence réduite de bactéries bénéfiques ou à une augmentation des bactéries pathogènes. Cela entraîne un déséquilibre dans la production de métabolites, ce qui favorise le développement d’inflammations et de complications métaboliques.

Certaines études scientifiques indiquent une corrélation entre la qualité de l’alimentation de la mère et la composition bactérienne du lait, ainsi qu’avec la présence de certains métabolites lipidiques et immunomodulateurs. Il a également été établi que la consommation d’acides gras oméga-3 peut influencer le profil inflammatoire et, éventuellement, la communauté microbienne transmise au nourrisson.

Effets à long terme

À l’heure actuelle, il n’existe pas encore de recommandations cliniques fondées sur le microbiome du lait. Cependant, le consensus scientifique tend à indiquer que l’alimentation maternelle peut avoir des effets qui vont au-delà des aspects nutritionnels, car elle pourrait également moduler le premier écosystème intestinal du bébé et influencer son développement et sa santé tout au long de sa vie.

Plus précisément, la colonisation intestinale précoce peut avoir un impact sur le risque ultérieur d’allergies, d’obésité, de maladies métaboliques et même de troubles neurocomportementales.

Des études longitudinales (menées sur la durée) suggèrent que les premiers mois de vie constituent une période critique de programmation biologique. Cela ne signifie pas que l’allaitement est le seul facteur déterminant : d’autres facteurs tels que le type d’accouchement, le recours à des d’antibiotiques, l’environnement familial et les déterminants sociaux de santé ont également une influence décisive. Néanmoins, cela implique le fait que nous sommes face à un aspect de l’allaitement qui, jusqu’à présent, avait été clairement sous-estimé.

Des données scientifiques aux politiques publiques

La pédiatrie moderne qui, traditionnellement, se concentrait uniquement sur des aspects tels que la nutrition et la croissance, commence à intégrer une perspective écologique. Selon cette approche, le bébé n’est plus un organisme isolé : il doit désormais être considéré comme un métaorganisme qui cohabite avec des milliards de microorganismes. Il existe un dialogue bidirectionnel entre le nouveau-né et le microbiote grâce à la production de molécules spécifiques qui ont un impact sur son développement et sur le fait que le bébé soit en bonne santé ou déclare une maladie. Et ce mécanisme commence à peine à être élucidé.

Ces nouvelles données autour de la composition du microbiote dans le lait maternel ne doivent pas devenir une nouvelle source de pression sur les mères : toutes ne peuvent pas allaiter et toutes n’ont pas accès à une alimentation équilibrée. Si la science confirme que la qualité nutritionnelle de la mère influence directement la colonisation microbienne du nouveau-né, la réponse ne peut être une responsabilité individuelle. Elle doit plutôt se traduire par des politiques facilitant l’accès des femmes en âge de procréer à une alimentation saine, ainsi que par un soutien à l’allaitement et des environnements de travail compatibles avec la maternité.

Sans aucun doute, investir dans la santé maternelle, c’est aussi investir dans la santé infantile. Et désormais, nous savons que cet investissement doit également tenir compte de l’alimentation de la mère. L’invisible – c’est-à-dire les bactéries, les métabolites et l’interaction entre l’alimentation et le microbiome – pourrait bien redéfinir la médecine de demain.

The Conversation

Juan Pablo Ochoa Romo a reçu des financements du secrétariat dédié aux sciences, aux sciences humaines, à la technologie et à l’innovation (SECITHI/Mexique).

Ana María Salazar Martínez, Erika Navarrete Monroy et Ivette Caldelas 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 poste universitaire.

ref. L’alimentation de la mère pendant l’allaitement pourrait jouer un rôle clé pour la santé future de son bébé – https://theconversation.com/lalimentation-de-la-mere-pendant-lallaitement-pourrait-jouer-un-role-cle-pour-la-sante-future-de-son-bebe-280878