It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Friday, February 06, 2026
‘Energy efficiency’ key to mountain birds adapting to changing environmental conditions
Research led by the University of East Anglia (UEA) sheds new light on how mountain birds adapt to changes in climate.
Scientists know that species diversity changes as you go up a mountain, but it is not clearly understood why this is the case.
One theory is that it is mostly because of long-term evolution, and the climate niches species have adapted to over millions of years. Another - the ‘energy efficiency’ hypothesis - suggests it is about how species today manage their energy budgets and compete for available resources that vary in space and time.
To test this, researchers looked at seasonal changes in the elevational distributions of birds - how high in the mountain birds go at different times of year - for nearly 11,000 avian populations across 34 mountain regions worldwide.
Publishing their findings today in the journal Science Advances, they found that many birds do not strictly follow the temperatures they are supposedly adapted to.
Instead, their movements match what would be expected if they were trying to use and acquire energy in the most efficient way based on today’s environments, with computer models simulating what birds should do to save energy corresponding with what they do in real life.
Lead author Dr Marius Somveille, of UEA’s School of Environmental Sciences, said: “A lot of mountain birds perform altitudinal migration - moving up and down the mountain with the seasons. This behaviour is common but not well-studied, and it has long been debated whether environmental conditions and biodiversity change with elevation in the same way they do with increasing latitude.
“We found that energy efficiency appears to drive both the seasonal distribution of birds across latitudes and along mountain slopes. This suggests that elevational gradients in avian distributions might be a condensed version of corresponding latitudinal gradients, and that altitudinal migration serves the same ecological purpose as long-distance migration, like flying towards the tropics for winter, saving energy and surviving in changing conditions.
“Understanding this is important as it helps us better predict how mountain birds will cope with global change.”
Dr Somveille added: “Human activity is affecting where energy and resources are available in mountain environments. Lower elevations are losing habitat due to human activity, while higher elevations stay more protected because they’re harder to reach. These shifts are likely to significantly change where birds can live and how they spread out across mountains.”
The team used publicly available participatory science data for 10,998 populations, belonging to 2684 species, to provide the most extensive quantification of seasonal distribution patterns of mountain birds to date.
Focusing on elevational gradients as natural replicates across mountain regions worldwide, and using seasonality as a natural experiment, the observed seasonal distribution of mountain birds was compared with computer model predictions based on energy efficiency.
The researchers found more than 30 per cent of the avian populations studied that live year-round on the mountain slopes are altitudinal migrants - defined as having average seasonal altitudes separated by more than 200 metres - confirming altitudinal migration to be a “notable phenomenon globally”.
Among these, only a few populations radically shift their distribution along the elevational gradient, for example by more than 1000 metres on average, mirroring the pattern observed for latitudinal migration, where few avian species migrate very long distances.
Altitudinal migration was found to be widespread - in 339 of 1852 populations - within the equatorial tropics despite minimal seasonal temperature changes in these regions.
However, the proportion of altitudinal migrants in a mountain region nonetheless increases with latitude, for example the further north of the equator that populations are, with the tropical Southern Ghats of India having approximately 20 per cent of bird species as altitudinal migrants, while the temperate Swiss Alps have about 57 per cent.
Located in subtropical mid-latitude, eastern Taiwan has approximately 43 per cent of bird species that are altitudinal migrants, such as the Taiwan Yuhina. Overall, this latitudinal pattern supports the idea that altitudinal migration is an adaptation to seasonality.
“Overall, our results suggest that the seasonal distribution of birds in mountains is largely shaped by a complex interplay between species minimising energy costs while maximizing energy acquisition and considering what competitors are doing,” said Dr Somveille.
“Also, that altitudinal migration is a behavioural mechanism allowing birds to optimise their energy budgets in the face of seasonality and competition. This explains the many populations that appear to engage in upslope migration during the colder season, as a distributional strategy that is energetically efficient for some species given the dynamics of competition for access to food.”
Dr Somveille, who started the research while at University College London, collaborated with scientists from the Georgia Institute of Technology and Yale University in the US, and Academia Sinica in Taiwan. It was supported by funding from the Wolfson Foundation and Royal Society.
‘Climate, ecological dynamics, and the seasonal distribution of birds in mountains’, Marius Somveille, Benjamin G Freeman, Frank A La Sorte and Mao-Ning Tuanmu, is published in Science Advances on February 6.
How do children learn to cooperate with others? A new cross-cultural study suggests that the answer depends less on universal rules and more on the social norms surrounding the child.
In the study, researchers examined how more than 400 children ages five to 13 from the United States, Canada, Peru, Uganda and the Shuar communities of Ecuador behaved in situations involving fairness, trust, forgiveness and honesty. The team also surveyed children and adults in each community to understand what people believed was the “right” thing to do.
The results show that while young children across cultures begin with similar, largely self-interested behavior (what maximizes resources for them, individually), their choices diverge over time in ways that reflect local cultural norms.
“We wanted to try and map the regularities and variation in how cooperation develops, and what it looks like across different cultures, which was the impetus for the cross-cultural developmental angle,” said Dorsa Amir, assistant professor of Psychology and Neuroscience at Duke University. “We wanted to uncover the roots of human cooperation, which surpass those of all other species in scale and flexibility.” m
From shared beginnings to cultural pathways
To look at how children make choices, researchers played a set of four simple games with them, where the children were asked to make choices about sharing resources (in this case, Starbursts), returning favors, forgiving mistakes, and telling the truth, often at a cost to themselves. Together, the games measured how children think about fairness, trust, forgiveness, and honesty in everyday social situations. Across all five societies, younger children tended to prioritize their own interests. But as children entered middle childhood, defined as roughly between ages eight and 13, their behavior increasingly aligned with their community’s values.
In some societies, children became more likely to reject unfair advantages or share their candy with anonymous others. In Shuar hunter-horticulturalist communities in Amazonian Ecuador, children focused on not wasting resources and getting the most out of what they had, which matched up with how their society functioned. In those areas of Ecuador, where resources are sometimes scarce, it may be more important for people to minimize waste than spread resources out equally.
“In cross-cultural research, it’s common to measure behavior and then speculate about the causes,” said Amir. “But we wanted to contextualize the work: to actually talk to people in these communities and understand how those choices fit their environment. What we find is that in places like Ecuador, these behaviors aren’t breaking a norm, they are the norm.”
Importantly, the researchers emphasize that these differences should not be interpreted as some children being more or less “moral” than others. Instead, children appear to be learning what kinds of cooperation make sense in their social world.
Learning what’s ‘right’, and when to act on it
To better understand how social norms shape behavior, the research team compared what adults believed others should do with what children actually did when faced with cooperative tasks.
They found that, in many cases, children’s behavior gradually moved closer to adult norms over time, especially when it came to fairness and trust. However, for some behaviors, such as honesty, children often knew the “right” thing to do before consistently acting on it.
Forgiveness stood out as an exception. Across all five societies, both children and adults showed strong agreement that accidental mistakes should be forgiven.
Different strategies for cooperation
Rather than showing a single, general tendency to cooperate, children in the study followed one of three distinct strategies: maximizing personal gain, cooperating broadly with unknown others, or cooperating selectively depending on the situation.
The prevalence of these strategies changed with age and differed across societies. In more industrialized societies, children were more likely to cooperate with strangers, perhaps because that was rewarded in their everyday life. But in societies where people rely more on close relationships and resources are scarce, children were more likely to focus on using the resources they have more efficiently. This, researchers said, doesn’t mean one set of children is more or less ‘cooperative’; rather, cooperation itself is culturally constructed and can take many forms.
Why middle childhood matters
The findings highlight middle childhood as a critical period for social learning, because that’s when children refine both their behavior and their understanding of how they’re supposed to act in society.
“Children become increasingly sophisticated at learning and picking up on norms through middle childhood,” said Amir. “In addition to learning the norms around them, they also start to behave more and more in line with those norms, which is sometimes hard to do because it could involve paying a cost.”
According to researchers, this extended period of learning allows children to fine-tune their behavior to fit the expectations of their community, a process that may be key to human cooperation more broadly.
Broad implications
By studying children across a wide range of cultural contexts, the research demonstrates that behaviors observed in U.S. children shouldn’t be treated as the global standard, challenging the frequent and sometimes implicit assumption that findings from Western, industrialized societies apply universally.
“It’s important to remember there isn’t one single ‘normal developmental pattern’ when it comes to behavior, because whatever we observe is happening within a culture,” said Amir. “There’s no culture-free development. You cannot take culture out of the developmental process.”
Around the world, children’s cooperative behaviors and norms converge toward community-specific norms in middle childhood, Boston College researchers report
Boston College researchers examined four cooperative behaviors—fairness, trustworthiness, forgiveness, and honesty—in children from Canada, Ecuador, Peru, Uganda, and the United States
Researcher Dorsa Amir, at the time a post-doctoral research fellow at Boston College, works with a child in Uganda completing a “fairness task” as part of a five-country study of the how cooperation develops in children.
Chestnut Hill, Mass. (2/6/2026) – Children across the globe engage in a constellation of behaviors that support cooperation, an action critical to the survival of the human species, a team of Boston College researchers report today in the journal Science Advances.
The team from Associate Professor of Psychology Katherine McAuliffe’s Cooperation Lab surveyed children in the urban United States, rural Uganda, Canada, and Peru, and the hunter-horticulturalist indigenous Shuar of Ecuador.
The researchers found there are cross-cultural regularities in some aspects of the development of cooperation — namely, that younger children tend to be self-interested, and that as children get older their behavior starts to reflect local norms, according to the report.
The researchers examined the development of four cooperative behaviors — fairness, trustworthiness, forgiveness, and honesty — in more than 400 children aged 5 to 13 from five societies. They also collected normative judgments from more than 160 peers and nearly 90 adults from each community.
“Cooperation is crucial to the success of our species,” said McAuliffe. “We were interested in how behaviors related to cooperation—fairness, trustworthiness, honesty, and forgiveness—emerge with age across diverse populations. We found some similarities, such as fairness and trustworthiness behaviors aligning with adult norms over age across societies. And we found some differences, such as variations in the norms themselves.”
The norms themselves contained cross-cultural differences. For instance, adults across cultures have different ideas of what constitutes “fair" behavior.
“There are cross-cultural regularities in some aspects of the development of cooperation — namely, that younger children tend to be self-interested, and that as children get older their behavior starts to reflect the norms of their broader society,” said co-author Dorsa Amir, a former post-doctoral researcher in McAuliffe’s lab and now an assistant professor of psychology and neuroscience and Duke University.
“We find cross-cultural differences in the norms themselves,” Amir said. For instance, adults across cultures have different ideas of what constitutes ‘fair’ behavior. Our study shows that children seem to be sensitive to those specific differences and tend to bring their behavior in line with them over time.”
The team worked with 5- to 13-year-old children and adults in Canada, Ecuador, Peru, Uganda, and the U.S. They designed four different child-friendly activities to measure fairness, trustworthiness, forgiveness, and honesty. For example, in the fairness activity, children used an intuitive wooden apparatus to make decisions about whether to accept or reject uneven divisions of candies between themselves and a peer.
The research found substantial variation in cooperative behaviors and norms across populations, but, more generally, that children’s behaviors and norms tend to converge toward community-specific norms in middle childhood.
The team also identified three cooperative strategies – maximization, generic cooperation, and partner-contingent cooperation – that become more prevalent with age and differ across societies. All told, the findings show how the differences and similarities present as cooperative behavior develops within and across cultures.
McAuliffe said the study, undertaken with funding from the John Templeton Foundation, built on previous work that had looked at children’s sharing and fairness behavior across societies to understand a broader suite of cooperative behaviors.
“By including a ‘cooperative task battery’ we were in a good position to explore how cooperative behaviors relate to one another,” said McAuliffe, referring to the collection of activities and tasks they administered during their sessions with participants in the study.
McAuliffe said the researchers were most surprised by the findings about the role of forgiveness.
“Our lab has done a lot of work on punishment behavior, finding punishment to be a common response to transgressions across societies,” she said. “Yet, here, both adults and children seemed to endorse forgiveness over punishment. It’s possible that, in past work, we have overestimated how much people want punishment because we haven’t given them alternative options such as forgiveness.”
McAuliffe and her team are working on a follow-up report from four of these same countries that looks at the mechanisms of norm transmission.
“Specifically, we are comparing the influence of adult and peer models in influencing children’s fairness and trustworthiness behavior,” she said. “This is an important extension of the current work because it goes beyond showing that children vary in their cooperative behavior and looks at how that variation may come about.”
Researcher Gorana González, at the time the coordinator of the Cooperation Lab at Boston College, works with a child in Uganda completing a “fairness task” as part of a five-country study of how cooperation develops in children.
