Harvard University professor Joseph Henrich said many trends showing up at the same time across modern societies — rising competition, anxiety among younger people, weaker social ties, growing loneliness, lower marriage and fertility rates, and declining trust — may be different faces of the same shift: people are no longer embedded in stable networks of mutual dependence, but are instead being pushed to function as if they can operate on their own.
Henrich, a professor in Harvard’s Department of Human Evolutionary Biology and the author of The Secret of Our Success, made the argument in a conversation with He Peikuan, founder and editor of Edu Guide. The interview was originally published by the WeChat account Edu Guide and later carried by MarsBit.
Human advantage comes from culture, not isolated intelligence
Henrich said the central claim in his work is that human beings did not dominate the world because each individual is exceptionally smart. The edge comes from collective intelligence, built through cumulative cultural evolution.
He pointed to a case he often uses to explain the idea. When European explorers entered unfamiliar environments, including places where hunter-gatherer groups had already lived for thousands of years, they often could not survive on their own. Even with powerful brains and strong cognitive ability, they could not simply figure out how to make tools, build shelter, prepare medicines, or navigate the land.
For Henrich, that pattern reveals what is distinctive about the species. Humans depend heavily on learning, especially learning from previous generations that have already tested and refined solutions suited to local environments. Ideas, techniques, technologies and rules of thumb accumulate over time, generation after generation, creating a cultural toolbox far larger than anything one person could invent alone.
That toolbox, he said, is the real engine behind humanity’s spread across the globe and its ability to adapt to very different environments. Human populations may be relatively similar genetically, but behavior differs sharply from place to place because local customs have been adjusted to local conditions.
Cumulative cultural evolution becomes smarter than any single person
Henrich described cumulative cultural evolution as a process of intergenerational transmission and revision. One generation passes on its beliefs, practices and ways of doing things. The next generation adopts them, uses them in daily life, makes small adjustments, drops some outdated elements, and then passes the package along again.
After many generations, the result can be a tool, institution or body of knowledge whose complexity exceeds what any single individual could fully understand in one lifetime. In that sense, he said, culture itself becomes smarter than any one person.
He extended the point to smaller units as well. A well-functioning team can display its own form of collective intelligence. Research, he said, suggests that when team members communicate effectively and bring cognitive diversity — different ways of seeing a problem — the group’s performance often exceeds that of its smartest member. A team can work like a larger brain, with members sharing, testing, challenging and improving one another’s ideas.
IQ reflects a cultural setting, not a timeless measure of intelligence
Asked whether modern society overstates the role of genius and IQ, Henrich said the issue has several layers. In his view, the human brain is shaped to handle the cultural world humans themselves have created. That means people develop specialized neural circuits suited to the challenges of a given environment.
He cited findings from neuroscience showing that when children learn to read, the brain forms dedicated circuits and even affects regions involved in face recognition. The example, he said, shows that brains are adjusted and specialized through cultural practice.
Henrich and his colleagues treat IQ less as a universal measure of intelligence and more as a set of cognitive abilities shaped by a particular cultural environment. In the 20th century, those abilities matched the institutions and incentives of industrial society. But that does not make IQ a permanent, all-purpose standard that works equally well across eras and environments.
He offered a contrast: a highly skilled hunter-gatherer on the African plains might not score well on a modern IQ test, but that would not erase the person’s survival knowledge. He also referred to the Flynn effect, the rise in IQ scores during the 20th century that first appeared in the most developed countries and later spread globally.
That rise may look like evidence that humans simply became smarter, Henrich said, but he sees it more as a sign of increasing cognitive specialization, reinforced by cultural transmission. Schooling is deeply tied to the pattern. Children who go to school learn literacy, arithmetic and specific games, all of which train the kinds of abilities IQ tests measure. At the same time, some other abilities may weaken.
He said his colleague Helen Davis found that pastoralists with no formal schooling were exceptionally strong at spatial navigation, including pointing toward the direction of a city, but that ability deteriorated once they entered school. In his account, IQ measures something closer to one’s ability to be an effective cultural learner in a 20th-century industrial society, such as absorbing vocabulary at scale.
In the 21st century, especially after the arrival of generative AI, the mix of cognitive skills people need may be changing again. Treating IQ as an eternal and general standard of intelligence may therefore be a mistake, he said.
Generative AI may reshape social learning and authority
Henrich called generative AI a rich subject for future research. People who use it actively are clearly learning through it in various ways. The unresolved question is what role it plays inside social learning.
Do users accept its answers outright, or treat them only as a starting point? If AI advice conflicts with a doctor or another traditional expert, who will people trust? Henrich said he has not yet seen deep research answering those questions, and expects the outcome to differ across people and contexts.
That uncertainty connects to a broader change in who counts as a model worth copying. In Henrich’s framework, humans are inclined to learn from people who appear more successful or more skilled — those with prestige. Prestige usually comes from being respected and followed by others.
In traditional societies, age often aligned with wisdom, because surviving to old age signaled competence and long experience. In fast-changing modern life, that link weakens. Grandparents grew up in conditions very different from those facing teenagers now, and that gap can lead younger people to see older experience as outdated.
Henrich said the shift does not lend itself to a simple positive or negative judgment. Some higher-level strategies for living — dealing with other people, handling adversity — may remain durable even when technical knowledge changes quickly. A younger person may be the best model for managing an Instagram account, while an older person may still offer better guidance on life problems.
How people decide whom to copy
Henrich said research on all age groups, including infants, shows that people use many cues when choosing whom to learn from. Success, skill and prestige are part of that set.
People also rely on cues of self-similarity. He said there appears to be a bias, already deeply rooted in young children, in which girls imitate girls and males imitate males. That tendency may be linked to labor division in human evolutionary history.
Language matters too. People are more likely to copy others who speak the same dialect and are easier to understand. The effect is not overwhelming in every setting, but he said it does show up at the population level.
Content itself affects transmission. Food-related information attracts attention in many parts of the world, which he said makes intuitive sense. Everyday reputation information also spreads easily. Gossip and negative information tend to move quickly, stick in memory and get repeated.
Another force is context. When differences are not large, people often follow the crowd. If most others are doing something, many individuals are more inclined to treat it as a good idea. Henrich did not describe that as blind conformity in every case, but he said the tendency appears across a range of domains.
Modern schooling weakens mixed-age learning
Henrich argued that one problem in modern education is the way schools cluster children by age while separating them from older and younger peers. He said that may be a mistake.
Anthropologists studying traditional societies have found that mixed-age play groups are crucial for child development. Older children imitate adults. Younger children imitate older ones. Older children also naturally take care of younger children. Those interactions create a direct setting for learning social skills, responsibility and empathy.
By contrast, age-segregated education may strip away those experiences. Henrich did not reject schooling itself, but he said this design changes the structure of social learning and removes part of the collective learning system that was once woven into everyday life.
Imitation is not the opposite of innovation
Henrich said a major insight from cultural evolution research is that humans rarely innovate from scratch. The important question is not whether people imitate, but under what conditions they rely on others rather than trying to solve everything alone.
Any invention starts from what already exists, and those starting points are themselves cultural products. Someone trying to invent a new communication device does not begin with branches and vines, he said, but with an existing phone or computer and then tries to improve it.
He added that if one examines major innovations or scientific discoveries closely, most turn out to be recombinations of existing ideas. A person can innovate through imitation by learning one idea from one source, another idea from someone else, and then joining them in a new way.
Asked how individuals can find good models to learn from, Henrich said the best approach is often to trust one’s intuition. Those intuitions, he argued, have been shaped by evolution and can be fairly reliable. He added one caveat: role models encountered in real life and face to face may have much greater influence than virtual figures seen on a screen.
Prestige and reproduction have split apart in modern life
When he spoke about “success,” Henrich first meant success at the species level. Humans are tropical primates by physiology and anatomy, he said, yet they have spread into all major ecosystems. In terms of accessible energy captured in terrestrial mammalian biomass, humans occupy a very large share. On that measure, he said, ants may be the only real competitor, especially once domesticated animals are counted. By that standard, humans are the world’s most successful species, or at least the most successful terrestrial vertebrate.
From the perspective of evolutionary biology, however, success ultimately comes back to survival rates and reproduction. Human learning capacities, in the final analysis, exist to improve both. In the modern world, Henrich said, those two aims have been short-circuited.
He pointed to the demographic transition that began roughly in the 19th century and drove fertility down sharply. In many countries today, fertility is below replacement level. Henrich and other cultural evolution researchers think one reason may be that prestige has come apart from genetic fitness.
In modern societies, the things that bring prestige — higher education, demanding careers — often lead people to have fewer children. In traditional agricultural settings, children could function as labor and a form of wealth. In a modern knowledge economy, children become a heavy commitment of time and energy. The kind of success pursued through cultural learning is no longer aligned with reproductive success in the genetic sense.
Low fertility may also slow innovation
Henrich said falling fertility should not be viewed only through household or family questions. It may also affect innovation. In cultural evolution, larger groups with tighter connections and greater cognitive diversity tend to innovate faster.
If population growth stops or populations begin to shrink, the growth rate of innovation may also slow. Stronger internal social ties could offset part of that effect, he said, but persistently low fertility may still carry a long-run cost in the form of lower overall innovation.
He noted that history has seen related patterns before. In ancient Rome, elite groups also faced low fertility. Later, the rise of Christianity increased fertility among believers by creating a different set of values and incentives. Henrich said future cultural or religious change could potentially alter current trends as well. For now, the global data still show that religious believers have higher fertility than nonbelievers.
Lower marriage, more solo living, more loneliness
Henrich said marriage decline is not his main research area, but he has noticed that lower marriage rates have moved in parallel with rising solo living. More people now live alone, and that increase overlaps with the spread of loneliness.
He linked the pattern, at least in part, to the rise of individualism. As people focus more heavily on personal traits and individual careers, they may become less willing to build traditional families or long-term stable relationships.
From a cultural evolution perspective, the deeper issue is that humans are a highly interdependent species. Research on hunter-gatherers shows that survival depends heavily on others in the group. Sharing food, defending one another and caring for the injured are ordinary parts of life.
Modern institutions now handle many of those functions, but Henrich said human emotional systems still want the feeling of interdependence and the experience of truly belonging to a group. Children who grow up without feeling that they contribute to family, friends or community may struggle more psychologically.
Even so, he said he remains optimistic. Cultural evolution may eventually solve the problem by creating new forms of interdependent community. Those forms may not look like traditional extended families or old neighborhood structures. They could be volunteer communities built around common interests, or circles of friends who help one another and even raise children together.
Henrich said people can reshape communities to meet the need for rich social interaction and genuine care. He also mentioned AI friends and AI romantic partners, calling the phenomenon strange and saying he is unsure how it fits into the broader story of cultural evolution.
From crowded Lunar New Year gatherings to the small urban family
When asked about the shift from large family gatherings during the Lunar New Year to smaller city households, Henrich said his view comes from many years of accumulated observation rather than one complete empirical case. A mix of reasonable economic incentives and the rise of individualism, he said, helps explain why extended families and clan structures have weakened.
But he added that this does not mean the new arrangement necessarily maximizes human flourishing. People tend to do better when they are part of an interdependent social world. There should be some people, he said, who truly rely on you, whose lives would be harder without you because you are part of the network they live in.
That sense of being needed can create warmth and security. Henrich said he expects societies to find ways to cultivate such networks again, perhaps not through a grand plan, but through social forms that still support flourishing, warmth and a sense of safety for people who might otherwise feel lost in big cities.
Individualism can help, but only up to a point
Henrich said the word “individualism” covers different ideas, and moderate individualism is not necessarily hostile to collective intelligence. It can support it. Encouraging people to develop their own traits and achievements can build confidence grounded in personal capability, making it easier to trust strangers and work with them.
In high-trust individualist societies, he said, people can meet in a bar, become collaborators, and exchange ideas freely. Scholars can share thoughts more openly. That social pattern has driven innovation and economic development over the past few centuries.
The problem starts when individualism drops below even the level of the nuclear family — what he described as an “atomic” or sub-atomic condition — leaving people to live alone, detached from any interdependent network and reliant only on impersonal institutions. When social trust is falling at the same time, mental health problems become more likely.
Online interaction still falls short of in-person contact
Henrich said current evidence does not support the idea that online social media can serve as a full substitute for offline life. Trust and creativity rely on many subtle elements present in face-to-face encounters: chance meetings, direct eye contact, shared laughter and the dense, immediate feedback that comes with being physically together.
As mammals, humans also depend on touch, hugging and other sensory experiences that may not even register consciously, he said. Those elements matter for emotion and memory. At least with today’s technology, virtual spaces do not reproduce them.
Anxious young people are losing real roles and collective support
Asked whether intense competition and anxiety among young people are inevitable features of modern life, Henrich said the issue connects directly to the broader discussion. Many young people now have very few chances to care for younger children or make concrete, adult-like contributions to the household.
He referred to his experience in Fiji, where 10-year-old children would go fishing after school, provide food for the family and help look after younger siblings. That sense of contribution to family and community can build confidence and create a deeper bond with other people, which in turn reduces stress and anxiety.
When people feel satisfied and happy, he said, their anxiety about competition tends to drop. One reason modern competition feels so intense is that these emotional supports have weakened or disappeared, leaving everyone focused on competing by themselves.
Henrich also referenced psychologist Jonathan Haidt’s idea of “the anxious generation,” saying social media captures one important factor. But he added that other forces matter too, including changes in child-rearing and the disappearance of collective structures. Children evolved, in his account, to grow up in mixed-age play groups and community settings. If a child is raised in a monogamous nuclear family with no siblings and very few neighboring children, that child is not really growing up inside a community.
His practical advice: invest in friends, relatives and real ties
At the close of the interview, Henrich’s advice was simple. Focus on building relationships and circles of friends. Invest time and effort in friends, relatives and other real social ties.
He said that kind of investment supports well-being and physical and mental health. It can also cultivate creativity and related abilities through the process of building and sustaining human relationships.
Across the conversation, Henrich did not argue against technology, education or modern institutions in any simple sense. His point was narrower and deeper: human beings should not think of themselves as self-sufficient units that can thrive once detached from other people. In his view, many of today’s pressures around anxiety, loneliness, marriage, fertility, trust and generational distance lead back to the same place — the collective learning system and interdependence that long supported human flourishing are being weakened.
This article was originally published by the WeChat account Edu Guide and credited to Edu Guide.