Tuesday, September 29, 2026

Children from six cultures reliably help their peers – but in different ways

New study shows that helping others is a universal part of childhood, shaped by local upbringing

Max Planck Institute for Evolutionary Anthropology

Children from Kenya’s Kikuyu community — image:
Although the ways in which children help their peers show subtle local nuances, the foundations of this behaviour are shared across cultures.
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Credit: © Henriette Zeidler

A new study by an international research team provides the first systematic, cross-cultural comparison of how children help their peers. While previous research has mainly focused on how children help adults, often within the family, peer interactions play an equally important, yet far less studied, role in children's social lives across many cultures.

Researchers from the Max Planck Institute for Evolutionary Anthropology, Sapienza University of Rome, Leipzig University, the University of Portsmouth, the University of Plymouth and Duke University studied 336 children aged four to nine from six different cultural groups: Germans, Wichí (Argentina), ≠Akhoe Hai||om (Namibia), Samburu and Kikuyu (Kenya) and Quechua (Bolivia). Spanning large-scale industrialised societies and small-scale foraging, farming and pastoralist communities, the sample allowed the team to examine children's helping behaviour across a wide range of social and economic contexts.

A simple game reveals a universal instinct

To capture children's spontaneous helping behaviour, the researchers designed a playful experimental setup that would feel natural across all settings. Pairs of children of the same age took turns playing a marble game. One child would observe the other encountering difficulties, such as a box that would not open or a container that spilled its marbles onto the floor. Having already learned how to solve both problems, the observing child could choose to help by explaining the solution, solving the problem hands-on, or doing both at once.

“This task showed us in a very direct and comparable way how children choose to help their peers when given the chance,” says Henriette Zeidler, a researcher at Sapienza University in Rome and the study's lead author. “What stood out immediately was how similar children's responses were, regardless of where they grew up.”

Helping that fits the need

Across all six cultures, children consistently helped their partners, doing so more often when help was genuinely necessary. For example, they were more likely to help a peer who was struggling to open a box than a peer who was picking up scattered marbles, a task that could easily be done alone. This sensitivity to their partner's actual needs became even more pronounced with age. While younger children helped in both situations at similar rates, older children increasingly reserved their assistance for moments when it clearly made a difference.

The way in which children helped also changed over time. Younger children mostly relied on providing practical assistance, doing the task for their peer, while older children increasingly offered information, explaining how a problem could be solved rather than solving it themselves.

Cultural fine-tuning within a shared pattern

Despite this overall consistency, the study revealed subtle yet reliable cultural differences in helping styles. German children were far more likely than those in any other group to provide both types of help simultaneously, solving the problem while explaining it. Kikuyu children, on the other hand, were somewhat less inclined to provide practical assistance than children in other cultures.

"These patterns mirror the everyday interactions that children are familiar with," Zeidler explains. "In many rural, subsistence-based communities, children learn largely by observing and helping out, with little verbal explanation involved. In Germany and similar places, however, parents tend to combine hands-on demonstrations with detailed verbal instructions, and children seem to apply the same approach when helping their peers."

Importantly, the researchers found no meaningful differences in helping behaviour between boys and girls, and the cultural differences that did emerge were modest in scale. None of the six populations stood out as clearly different from the overall cross-cultural pattern.

A shared foundation, locally expressed

Combining a carefully standardised experimental task with a uniquely diverse cross-cultural sample offers rare insight into how deeply rooted yet flexible children's helping behaviour really is. “Helping is one of the clearest expressions of our species' capacity for cooperation,” says Daniel Haun, one of the study's senior authors and a director at the Max Planck Institute for Evolutionary Anthropology. “Our data show that this capacity reliably emerges in children everywhere, but it is fine-tuned by the specific social world in which each child grows up. Children don't just learn whether to help; they also learn how to help in ways that make sense within their own community.”

Journal

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2515233123

Article Title

Children from six cultures reliably help their peers - but in different ways

Article Publication Date

28-Sep-2026

In the standardised game used in the study, children could help their peers by doing a tricky part of the task for them, explaining how to do it, or doing both — tailoring their help to what was needed.
Credit
© Henriette Zeidler

Largest-ever study of its kind shows California’s rodenticide restrictions are working, and flags new rodenticides rising in their place

A seven-year, 1,000-plus owl study gives some of the clearest evidence yet that science-based policy is reducing wildlife exposure to pesticides, even as researchers warn a second, less-regulated compound may be moving in.

Integral Ecology Research Center

Two Barred Owls — image:
An adult Barred Owl perches next to a juvenile.
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Credit: Daniel Hoftader

BLUE LAKE, Calif. September 25, 2026 - New research from the Integral Ecology Research Center (IERC) offers some of the clearest evidence yet that California’s efforts to restrict dangerous rodenticides are paying off in the wild, while also flagging a new contaminant that deserves close attention going forward.

The study, published in the journal Environmental Pollution, analyzed liver tissue from 1,003 Barred Owls collected across northwestern California between 2019 and 2025, the largest rodenticide biomonitoring dataset ever assembled for a single wildlife species in North America. Because the owls were removed as part of an ongoing regional conservation program rather than recovered as sick animals or dead carcasses, the sample is a far more representative picture of the population as a whole.

The findings are a mix of a genuine policy win and a new warning.

The policy win: Among young owls sampled in the study area, exposure to the most lethal class of rodenticides, known as second-generation anticoagulants, fell from about 50% of birds in 2019 to about 20% in 2024. That decline lines up closely with California’s phased statewide restrictions, most notably the California Ecosystems Protection Act (AB 1788), passed in 2020, along with a 2024 law extending restrictions to older-generation compounds (AB 2552). It also reflects a feedback loop central to IERC’s work: supplying the science that informs policy decisions, and then documenting the real-world benefit that policy delivers within just a few years.

The new concern: At the same time, the study screened for cholecalciferol (vitamin D3), a different type of rodenticide, for the first time in this species. It turned up in nearly one in five owls (18.5%), and detections rose over the same period that anticoagulant exposure was falling, a pattern suggesting product substitution as older compounds become harder to access. Overall, when all rodenticides were counted, as much as 46% of the owls sampled carried at least one rodenticide compound in their system.

The Spotted Owl connection: Female Barred Owls and older adults carried the highest exposure and the widest mix of compounds, consistent with pesticides accumulating over a lifetime. These are exactly the individuals, breeding-age females and established territory holders, that a population depends on most to sustain itself. Because Northern Spotted Owls are a closely related species with a higher proportion of rodents in their diets, this pattern may indicate added risk for Spotted Owl recovery.

“Nearly all rodenticide surveys rely on animals that turned up sick or dead, so they tend to capture the worst cases,” said Dr. Vitek Jirinec, lead author of the study and research scientist at IERC. “Our owls were apparently healthy birds going about their lives. That gives us a much truer picture of what’s circulating in the population, and more confidence that the trends we see are real.”

Dr. Greta M. Wengert, co-founder and co-director of IERC and principal investigator on the study, has tracked rodenticide contamination across the region for more than a decade. She said the results demonstrate something rare in conservation science, a policy translating directly into a measurable outcome for wildlife:

“We’ve watched illegal use and unregulated products drive rodenticide exposure in these forests for more than a decade,” said Wengert. “Seeing anticoagulant exposure actually decline within a few years of California’s regulations taking effect is proof that policy, when it’s grounded in good data from effective biomonitoring efforts, can improve outcomes for wildlife.”

The study also reinforces and extends findings from earlier IERC research. A 2012 IERC study first documented widespread anticoagulant exposure in Pacific fishers linked to trespass cannabis cultivation on public lands, and a 2018 IERC study found rodenticides in 70% of sampled Northern Spotted Owls in the same region. Barred Owls, Spotted Owls, fishers, and other sensitive wildlife all feed from the same contaminated food web, so this much larger dataset adds substantial weight to that earlier evidence. Across more than a decade of IERC research, the same underlying threat has persisted in multiple old-growth-dependent species, and it is now, for the first time, responding to policy.

The authors caution that the exact source of ongoing exposure is not fully resolved. State pesticide-use records only capture licensed commercial applicators, not household purchases or illegal use. Trespass cannabis cultivation, long documented by IERC as a major source of rodenticide contamination on public and tribal lands, remains untracked by any regulatory database, and legacy contamination from past illicit grow sites may also continue cycling through these forests well after active cultivation has stopped. Researchers say these hidden and historical sources likely explain at least part of the exposure that remains even as legal, regulated use declines.

About the Integral Ecology Research Center

Founded in Blue Lake, California, in 2004, IERC is a woman- and minority-founded nonprofit conservation science organization dedicated to conserving wildlife and the ecosystems they rely on across northwestern California and beyond. IERC partners with tribal, state, and federal agencies to conduct field research, from GPS telemetry and forensic wildlife science to toxicology and habitat monitoring, that translates directly into on-the-ground conservation action for species. Learn more at iercecology.org.

Publication: Jirinec, V., Gabriel, M.W., Peery, M.Z., Higley, J.M., Hofstadter, D.F., Varian, C.P., Rex, A., Franklin, A.B., Poppenga, R.H., Woods, L.W., Volker, S.F., Wengert, G.M. 2026. Forest food web contamination by rodenticides is pervasive but responsive to regulation: Insights from Barred Owl biomonitoring. Environmental Pollution, https://doi.org/10.1016/j.envpol.2026.129205

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