Culture and Context Matter when Thinking about the Phenomena of Ownership

– by Ulises Espinoza

The evolutionary social sciences have long sought to comprehend human commonalities. Among these inquiries, a central focus revolves around identifying the traits that collectively compose the so-called “human nature” of our species, in both their psychological and behavioral dimensions. It prompts us to ponder whether certain traits, transcending cultural boundaries, are universally present during early childhood. This often involves the establishing of connections between these putative universal or prevalent traits and their evolutionary origins, shaped by the forces of natural selection in the distant past. One particularly intriguing arena of exploration is in the domain of ownership, and the conceivable underlying psychological and cultural norms and regulations that govern it.

It’s likely that all humans have the capacity to recognize ownership in themselves and others. However, it is an open question whether there is a specific, species-typical human psychology of ownership, and whether that psychology contains particular rules or principles. In principle, it is possible that ownership is a purely cultural phenomenon. But there may also be evolutionary roots to how we conceptualize ownership and to the domains to which ownership is extended. In a recent paper, H. Clark Barrett and I delve into the intriguing question of whether ownership has possible universal features. We explore a set of norms called “first mover norms,” which suggest that the person who takes the initial action or makes the greatest effort towards an ownable object is socially recognized as its rightful owner. These norms can apply to various tangible and intangible items. Studies have shown that children, in primarily Western samples, tend to develop these first mover intuitions during early to middle childhood, suggesting a potential universality. Cross-cultural research has also supported these findings, although with some variations in developmental patterns. However, when examining ethnographic evidence, the picture becomes more complex. While first possessor rules exist in non-Western legal systems, many societies have diverse ownership norms. Ownership rights can be communal, partial, or subject to negotiation based on principles like kinship, sharing, stewardship, use, and need. Even in cases where first mover norms appear to apply, they often don’t confer permanent, individual ownership, as other cultural principles determine rights.

Our investigation ventured into the realm of ownership within Achuar communities, renowned for their distinctive fusion of individual autonomy and robust communal values. To shed light on the subject, we conducted experimental scenarios involving ownership claims in two culturally pertinent domains: land and hunting. To ensure cross-cultural comparability, we also included participants from the United States. Among the American participants, the notion of “first possession” held considerable sway in their judgments across various scenarios, whether related to hunting or land. Their consistent preference for the first possessor as the rightful owner aligns with the historical and cultural influences in American and European societies, where the concept of first possession has exerted a profound influence on the development of legal and cultural norms. Conversely, Achuar participants showed a less consistent bias towards first possession, depending on the context. In hunting scenarios, they recognized the person who captured a game animal as the owner, reflecting their cultural practices. However, when it came to assigning ownership of land, they prioritized factors like use and improvement over mere first possession. This reflects their belief in land stewardship and the idea that ownership is not static but earned through active use and care. These results highlight the dynamic nature of the of the use of first-mover norms, particularly concerning their role in determining actual ownership across diverse cultural contexts. Americans, and potentially Westerners more broadly, appear to lean toward the heuristic of first possession, while other cultures, exemplified by the Achuar, consider a broader spectrum of factors when adjudicating ownership. The concept of ownership is nuanced and exhibits considerable divergence on a global scale, challenging the notion of a universally shared human comprehension of this concept.

Our findings underscore the necessity of exercising caution when extrapolating from specific cultural samples to the broader global population (Barrett, 2020). This holds particularly true for various facets of human psychology, including those, like ownership, that are profoundly influenced by cultural factors. It suggests that studies conducted in the United States and Europe may possess limited applicability when seeking to generalize findings to broader populations. It prompts us to reevaluate the notion that an evolved psychology of ownership, while potentially existing in humans, may be significantly influenced by cultural distinctions and the intricate tapestry of cultural history. Our study represents a modest and preliminary exploration of ownership intuitions within Achuar communities. We believe that future research endeavors in this community, as well as in other Indigenous communities characterized by distinct ownership traditions diverging from those of European-descendant communities, hold the key to presenting a more comprehensive portrait of the variations in human ownership psychology and the commonalities that may exist across diverse human societies. Each contemporary human community serves as a valid exemplar of the myriad potential configurations of evolved human psychology, each bearing an equally extensive cultural heritage. Rather than idealize certain communities as superior or inferior exemplars of evolved human nature, evolutionary social scientists can reap significant benefits from examining the complete spectrum of contemporary human psychologies. This approach provides valuable insights into the essence of human nature, elucidating both its defining characteristics and the boundaries that demarcate it.

Read the original paper: Espinoza, U., & Barrett, H.C. (2023). Cultural and contextual variation in first mover norms of ownership: evidence from an Achuar community. Evolution & Human Behavior, 44(6), 584-596.

This article is part of the Special Issue – Dispatches from the Field Part II.

Life in Chocó, Colombia

Human intergroup relations are profoundly flexible. Our science needs to catch up.

– by Anne Pisor

Is intergroup aggression part of human nature? Or is intergroup tolerance part of human nature?

Yes and yes.

While such simple headlines make great clickbait, they oversimplify – yet both have a grain of truth. Humans are both profoundly hostile and profoundly tolerant toward out-groups. We’re profoundly flexible.

Flexible intergroup relations have deep evolutionary roots. Though chimpanzees are often thought of as hostile toward out-group members and bonobos as tolerant, there is some variation in chimpanzee intergroup relations and quite a bit of variation in bonobos. Given the range of opportunities for conflict and cooperation in humans – from defending resources and protecting ourselves, to exchanging resources and ideas – the profound flexibility of human intergroup relations shouldn’t surprise us.

Indeed, as Cody Ross and I write in a new piece in Evolution & Human Behavior, our behavior toward members of other groups is influenced by a whole pathway of things, starting with context (are resources scarce?) and individual characteristics (did my past interactions go poorly?) that affect our beliefs, attitudes, and motivations – our internal states. Context, individual characteristics, and internal states influence how we behave.

For example, take research led by Cody in rural Colombia, where indigenous Emberá and Afrocolombians live side by side – sometimes with discord, sometimes without. In one community, Emberá have more control over natural resources and there’s a history of intergroup tensions. Even though Afrocolombians are wealthier than Emberá in that community, Afrocolombians feel that intergroup tensions are high and cooperation low – and they share less money and food with Emberá households accordingly. In another community with less unequal resource control and less history of intergroup tensions, wealthy Afrocolombians share with poorer Emberá. The impact of context on our internal states and our subsequent cooperative behavior is not to be underestimated.

Capturing the profound flexibility in human intergroup relations requires methods that document it accurately. In our Evolution & Human Behavior article, Cody and I focus on a subset of intergroup relations called parochial altruism: in-group favoritism paired with out-group hostility. Variance in parochial altruism is best documented using a combination of methods, we argue, like experiments that measure who people prefer to share with, observations on who they actually share with in everyday life, and self-reported internal states.

Using just one method can generate bias. For example, as Cody has documented in Colombia, people may not reciprocate sharing in real life because they can’t afford it, but will preferentially repay real-life sharing in an experiment when researchers provide the money. In short, to triangulate reality, researchers must approach it from a variety of angles.

If intergroup behavior is so flexible in humans, why are simple headlines about it so common? One reason is that they often seem to either confirm or challenge our own internal states – “yes, of course humans are inherently violent”; “no, violence isn’t part of human nature!” Our own internal states are themselves products of our experiences and cultural contexts, among other things. Journalists know that headlines that confirm or challenge our internal states excite our emotions, making us more likely to click.

But these headlines are also common because researchers have their own internal states too, and these influence what research actually gets done. As Brian Hare and Vanessa Woods remind us in Survival of the Friendliest, research on intergroup violence ticked up after World War II: researchers wanted to understand how atrocities could be committed on such massive scales. Science can be guided by researchers’ own experiences or by history, which impact researchers’ beliefs about intergroup hostility, tolerance, and peace.

When there is a greater diversity of experiences among researchers, science is the better for it. It increases the diversity of research questions researchers ask, and having a range of research questions can better tap the range of the human experience – our flexibility in intergroup relations, for one. In turn, this data can be leveraged for policy recommendations and action – for example, what features of context, individual characteristics, and internal states have the greatest downstream influence on intergroup behavior? Which lever should we pull to intervene, reducing intergroup hostility?

As Cody and I highlight, answering these diverse questions about intergroup relations requires data that accurately reflect the diversity of human experiences – our profound flexibility. Ensuring data collection reflects research questions, triangulating across multiple types of measures, striving to ensure measures reflect reality – this will improve our understanding of human intergroup relations and the upstream factors that influence it.

War in Israel and Gaza, tensions over fossil fuels at COP28, impasses in parliaments and US Congress – these stories bring to mind humans’ profound intergroup hostility. Communities helping one another after a storm, organizations standing together on picket lines – these bring to mind humans’ profound intergroup tolerance. For researchers and non-researchers alike, our beliefs, attitudes, and motivations are affected by what’s around us and by our past experiences. When researchers bring that diversity of experiences to science, our understanding of human nature can also become more accurate – but only if researchers also get accurate measures of what humans are up to. Existing data already undercut the narrative that humans are doomed to favor in-groups and be hostile toward out-groups: the data instead reveal profound variability. Recognizing this variability can push scientists to challenge their own preconceptions about human nature and to draw upon a more diverse toolkit, improving our understanding of the flexibility of intergroup relations. The better we understand it, the better positioned we’ll be to address the pressing social issues of the 21st century.

Read the original article here: Pisor, A.C., & Ross, C. (in press). Parochial altruism: what it is and why it varies. In press at Evolution & Human Behavior.

Author’s note: the author thanks Cody Ross, Kris Smith, and Eleonora Zanetti for helpful comments on this piece. Photo credit: Karl Frost.

Unmaking egalitarianism

– By Christopher von Rueden

(Photo credit: Chris von Rueden. Tsimane man mediating a dispute over land)

The pre-agricultural past may have been more politically diverse than often assumed (see here), but it is likely that political egalitarianism predominated. As observed in many modern hunter-gatherers, political egalitarianism is a collectively-enforced emphasis on individual autonomy and freedom from coercion. A long-debated question, therefore, is why individuals in relatively egalitarian societies would acquiesce to greater political inequality, particularly where this wasn’t forced on them by outsiders.

In their recent tome The Dawn of Everything, the anthropologists Graeber and Wengrow argue that political transitions throughout history were the result of ideological experimentation, largely untethered to the material or demographic conditions of societies. Their argument gains apparent support from the fact that even some hunter-gatherers had chiefs and kept slaves. Hunter-gatherers from the Pacific Northwest coast of North America are the canonical example. Clearly, agriculture is not a necessary explanation of the “origins” of such inequality. Nor is it sufficient. Many societies that practice minimally intensive agriculture (i.e. horticulture) are relatively egalitarian.

Models that focus less on subsistence type per se have greater power to explain why societies differ in political inequality. Different models emphasize different determinants of inequality, which include: (1) reduced dependence on widespread food-sharing to buffer risk, which can weaken motivations to enforce political equality (see here); (2) larger and denser populations, which can increase the appeal of formal leadership as a solution to interpersonal conflicts, coordination problems, and collective action problems (see here); and (3) disparity in control of productive land and other forms of wealth, which engenders relationships based on patronage and indebtedness (see here).

Debate over these and other models continues because studies that compare models are few. Furthermore, tests tend to rely on archaeological cases studies or cross-cultural comparison based on ethnographic databases like the Ethnographic Atlas. These approaches typically lack fine-grained data on changes in inter-personal relationships to directly test parameters of the relevant models.

In my paper recently published in Evolution and Human Behavior, I present another approach: longitudinal observation of a current small-scale society (Tsimane horticulturalists), who retain some independence from state institutions and whose politics remain fairly egalitarian. Most extant small-scale societies like the Tsimane have been increasingly exposed to the threats and opportunities associated with market integration and inter-cultural exchange, which I argue can generate the conditions upon which various models of political inequality depend.

The Tsimane people live in villages ranging from 30 to 700 individuals in the tropics of lowland Bolivia. Their economy is based on food-sharing and collaboration in horticulture (plantains, manioc, rice, and corn), hunting, fishing, and gathering, which tend to be concentrated within extended families residing in the same or nearby households. Average individual income for the Tsimane is <2 US dollars per day, largely from the sale of horticultural products and lumber and from sporadic wage labor with loggers or cattle ranchers. Income opportunities accelerated in the 1970s, with the arrival of roads to the nearest market town.

Tsimane politics is largely informal. Conflicts tend to be resolved by the parties directly involved, and sometimes third parties within a village may step in to help mediate. Villagers also hold occasional meetings, which are used to mediate more intractable conflicts or to plan collective action, such as maintenance of community trails, confrontation of illegal loggers or other colonists, and negotiation with merchants and outside political bodies.

For my recent paper, I describe variation in men’s political inequality across four Tsimane villages, as well as variation over time within one of these villages. I measure inequality as the Gini coefficients of villagers’ rankings of each other, according to “whose voice carries the most weight during community debates”. The focus on men is largely due to an absence of data on women’s political influence beyond a single village. In that village, men’s political influence was more variable and on average higher relative to women’s political influence (see here).

I found that market proximity matters. Inequality in men’s informal political influence is greater the closer the village is to the market town, and increased over a twelve-year period in the village closest to the market town. So what about market proximity could explain these trends? Villages closer to the market have higher average household incomes, which could undermine the incentives to widely share food as well as the status-leveling that helps maintain such sharing. However, I found no evidence consistent with this possibility: average number of food-sharing partnerships did not decline with greater political inequality.

There is greater evidence that Tsimane political inequality reflects demand for leadership, in order to more effectively deal with increased intra- and intergroup conflict. In the more market-proximate and politically unequal villages, men report more interpersonal conflicts, particularly conflicts with non-Tsimane, and the most influential men perform a much larger share of conflict mediations, like the man in the photo at the top.

While income inequality did not clearly associate with political inequality either cross-sectionally or longitudinally, men who use their income to hire or indebt others may gain political advantage. Closer to the market town, a small percentage of field labor help is now paid rather than reciprocated in kind. However, the most influential men are only slightly more likely to be labor patrons, and only in the final year of analysis did labor patronage predict men’s influence independent of other predictors, including conflict mediation.

Wealth differentials will likely increase in the future as some Tsimane further scale up their cash cropping via labor patronage, while others opt for more traditional lifestyles. Over the longer term, land may become de jure privately owned at the household level in response to escalation of land conflicts. These changes may precipitate a shift from more mutually beneficial political inequality–motivated by a demand for leadership– to ever-growing and elite-enriching political inequality–enabled by differential resource control. Indeed, such a shift may have been characteristic of inequality increases throughout the Holocene (see here). Studies of the Tsimane and other small-scale societies in transition will help us better understand how continuous change in political inequality can precipitate more qualitative shifts, such as the emergence of chiefs or other inherited positions of coercive authority.

Read the original paper here: von Rueden, C.R. (2023). Unmaking egalitarianism: comparing sources of political change in Amazonian society. Evolution & Human Behavior, 44(6), 525-652.

Author’s Note: The paper describing the above was published as part of the Evolution and Human Behavior special issue, “Dispatches from the field: insights from studies in ecologically diverse communities: Part 2”. The special issue is dedicated to the late John Patton, and also acknowledges the recent passing of John Tooby. Their influence on my paper and the others in the collection is enormous. I am equally indebted to my dissertation advisor and frequent collaborator Mike Gurven, Hillard Kaplan, and the Tsimane Health and Life History Project. We recently established a scholarship fund for the first Tsimane women and men to attend university, in disciplines like medicine, law, engineering, and business administration. Consider supporting us in building a generation of Tsimane leaders with the capacity to meet their many challenges to a sustainable future.

 

What is reciprocity, anyway?

– by Diego Guevara Beltrán, Jessica Ayers, Lee Cronk, & Athena Aktipis

Thirty-four experts on cooperation walk into a bar and begin to discuss the ‘true’ meaning of the term ‘reciprocity.’ A biologist offers one definition. She says, “we observe reciprocity when the gift of some food, or another favor, increases the probability for the donor to receive the same thing, or something else, from the receiver”.

Perhaps because that approximates one of Robert Trivers’ definitions of reciprocal altruism, all experts nod in agreement with the biologist. However, not being quite content with this definition, an economist retorts “[that the] formulation is rather sloppy.” His colleague adds that “reciprocity should be conceptualized as reciprocal strategies in repeated games, normative obligations, and individual preferences to respond to kind acts with kind acts and to unkind acts with unkind acts.”

“Yes, yes, but how do we operationalize reciprocity?” asks one psychologist. He says, “The best statistical definition is the contemporaneous correlation of two individuals’ responses within time-series regression analyses and as partner effects among these variables.” Intrigued but bewildered, another psychologist adds “reciprocity is reciprocity, that’s what I was taught! Because he gave to him and he gave to me, then I gave to her, albeit indirectly. But I couldn’t keep track of who gave what to whom, what I owed to him, or who I should groom. Maybe we should just avoid this definitional animosity and just call all transfers something-something reciprocity!”

A review of the literature yields a proliferation of reciprocity-related terms – thirty-four at last count. That might lead you to believe that experts indeed agreed with the bewildered psychologist. Perhaps experts want to avoid definitional animosity and decided to call all transfers “something-something” reciprocity. With several conflicting, overlapping, and even a few redundant terms, it was clear there is no consensus among scholars regarding what truly constitutes reciprocity. In fact, these terms continue to proliferate, as evidenced by the preceding paper in the same issue of Evolution and Human Behavior (i.e., “dynamic indirect reciprocity”). This lack of consensus and the continued proliferation of terms motivated us to review the term reciprocity and survey cooperation experts about it.

In our study, we asked 85 cooperation experts to rate the extent to which they believe thirty scholarly definitions of the term reciprocity were truly reciprocity. Some of these definitions (e.g., indirect reciprocity: return is expected from someone other than recipient of benefit) are common in the literature, while others (e.g., homeomorphic reciprocity: exchange of things that are the same) not so much.

We first wanted to know whether experts’ responses would help us identify underlying dimensions of reciprocity (i.e., characteristics that cluster some, but not other, terms together). Applying factor analyses, we find that the scholarly definitions of the term reciprocity can be represented by four broad dimensions: (1) Balanced Transfers (i.e., transfers that are of equal or equivalent value), (2) Reputation-based Transfers (i.e., transfers where individuals give to others who have given in the past and receive from others if they have given in the past, (3) Debt-based Transfers (i.e., transfers where individuals keep track of, and expect repayment for, what they give to others), and (4) Unconditional Transfers (i.e., transfers that do not revolve around concepts of debt or account keeping). This four-factor framework captures greater variation in types, or dimensions, of transfers than previous frameworks (e.g., direct, indirect, and generalized reciprocity).

We encourage experts to consider adopting these terms. In doing so, we can provide specific qualifiers to a transfer while at the same time reducing the possible number of dimensions that describe a transfer based on whether, or the extent to which, they are balanced, debt-based, reputation-based, or unconditional. For example, we saw that several experts used the same term (e.g., indirect reciprocity) to describe multiple different reciprocity terms. Hence, our framework would allow experts to avoid using overlapping terms to describe different dimensions of transfers, ultimately improving communication within and between disciplines.

We then assessed the level of consensus among experts regarding what truly constitutes reciprocity. There was no consensus regarding what should be considered reciprocity. However, over 90% of experts agreed that unconditional transfers (e.g., generalized reciprocity I: non-conditional sharing and giving of assistance) should not be considered reciprocity. So, although experts do not yet agree on what truly constitutes reciprocity, these findings suggest that the scholarly community can move beyond discussions of whether unconditional transfers should or should not be considered reciprocity. They should not be.

Instead, the scholarly community might consider focusing on outstanding disagreements, such as those identified in our study. For example, some experts believe that transfers are reciprocity only if agents have the intention to reward a giver or incentivize a receiver to give back, while others do not think intentionality is a defining feature of reciprocity. Similarly, some experts believe that reciprocity must involve a cost, while others believe that reciprocity does not involve cost or transfers with negative utility.

Focusing on these issues might help experts reach a consensus regarding what truly constitutes reciprocity. However, we might also supersede these disagreements by adopting the language of Balanced, Debt-based, Reputation-based, and Unconditional transfers. Does it matter for the study of evolution and human behavior whether unconditional giving is or is not reciprocity? We think not. What matters is that we reach a deeper understanding of the ultimate causes and proximate mechanisms underlying the diversity of transfers that have shaped the evolution of human behavior. While our framework does not include information about the ultimate causes of behavior, it provides information about the proximate mechanisms underlying an individual’s decision to engage in a transfer. Overall, we hope our study allows the scientific community to gauge the current level of consensus, or lack thereof, regarding the term reciprocity, and ease communication across academic fields.

Read the original article: Guevara Beltrán, D., Ayers, J.D., Munoz, A., Cronk, L., & Aktipis, A. (2023). What is reciprocity? A review and expert-based classification of cooperative transfers. Evolution & Human Behavior, 44(4), 384-393.

Are parents naturally biased towards their sons or daughters, depending on their conditions?

– by Valentin Thouzeau

According to Robert Trivers and Dan Willard’s hypothesis, in many species, parents in good condition should favour male offspring, while parents in poor condition should favour female offspring. Why? First, parents with more resources can support more offspring. Second, in polygynous species, males with more resources are more likely to have many offspring. Natural selection should therefore favour investment in male offspring when parents are in good condition, since their sons will have a chance to have many children in turn. Conversely, natural selection should favour investment in female offspring when parents are in poorer condition, since their daughters have a high chance of having children even if they do not have many resources (see Figure 1 for a schematic representation of this hypothesis). This prediction was tested in a numerous non-human species. For instance, in ungulates, the results showed that when a female’s partner can invest more resources in her offspring, she does indeed produce more sons.

Figure 1 – a) Example of a group in which males with many resources (represented by large circles) are likely to have more offspring than females with many resources, since they can have children with multiple females. b) Representation of the optimal choice in terms of investment by parents in a population represented in a. Parents with few resources should favour their female offspring, while parents with many resources should favour males. c) Prediction of the Trivers-Willard hypothesis arising from the choice in b. The sex ratio of offspring from parents with few resources should favour females, while it should favour males for parents with many resources.

But can this prediction be applied to humans? We often think we are above biology – yet some results seem to contradict this: one study showed that American millionaires have an average of 60% sons and 40% daughters! Does this prediction apply to how we treat our children? In another U.S. study, no difference was found between parents based on socioeconomic status in the amount of time they spend with their sons or daughters. So the results are uncertain.

At present, there are literally hundreds of studies testing the hypothesis in humans, and it is difficult to get a comprehensive view. Also, can we trust the proportion of results that support the Trivers-Willard hypothesis? It may be that researchers were more inclined to publish results that supported the hypothesis rather than those that invalidated it, which may have led to publication bias. We were surprised to find that results from studies involving many groups of animals were synthesised (this is the case, for example, for ungulates and non-human primates), but no synthesis of the work done in the human species had been undertaken until now. This is why we started this work.

We collected 87 studies reporting a total of 821 tests of the Trivers-Willard hypothesis. Although the majority of the samples were based in North America, the geographic coverage was considerable. The analysis of all these studies reveals that the results are largely compatible with the Trivers-Willard hypothesis and that there is no publication bias in this scientific literature that could alone explain the compatibility of the results with this hypothesis.

We then tested whether the hypothesis held true in the birth bias of boys and girls, in the investment bias that boys and girls receive after birth, or in both. We found that tests for both versions are equally prevalent in the scientific literature. However, the results indicate that birth bias is better supported than investment bias. Putting together the last 50 years of research on the Trivers-Willard hypothesis thus allows us to conclude that parents in good condition have, on average, more sons, while parents in poor condition have more daughters.

We have to keep in mind that even if the Trivers-Willard hypothesis is validated for the birth bias, this bias is very small (the correlation coefficient is 0.037). There is simply a very small additional probability of giving birth to sons when conditions are favourable, and to daughters when conditions are less favourable. Nevertheless, these results show how the theory of evolution leads to surprising predictions that allow us to discover unsuspected phenomen.

Read the original paper: Thouzeau, V., Bollée, J., Cristia, A., & Chevallier, C. (2023). Decades of Trivers-Willard research on humans: What conclusions can be drawn? Evolution and Human Behavior, 44(4), 324-331.

What’s punishment like in small-scale societies?

by Léo Fitouchi (Image credit Frans Huby, Creative Commons 3.0)

Humans want wrongdoers to suffer. From the justice courts of modern societies to the biblical “eye for an eye,” people everywhere have rules for punishing transgressions including theft, murder, assault, or property damage. Why do human societies punish wrongdoers? You might think the answer is simple: to teach offenders a lesson so that they don’t offend again and the group can function well.

This intuition—that punishment serves to enforce collective norms—reflects in many strands of social science. Émile Durkheim, the French founder of sociology, argued that punishment serves to reaffirm the sacred values of the group, thereby reinforcing group solidarity. More recently, evolutionary social scientists assume that humans feel the need to punish norm-violators even when their behavior doesn’t harm the punisher directly—a behavior called third-party punishment. We humans would be normative animals, deeply committed to getting deviants back in line, for the good of the group and at a cost to oneself.

In this view, third-party punishment is not only a universal feature of human psychology; it also explains why humans are so cooperative compared to other species. By imposing costs on antisocial actors, third-party punishment would have selected for higher levels of cooperation during human evolution.

Despite these wide-ranging claims, however, few recent studies have examined how punishment operates in the social contexts where our punitive psychology is assumed to have evolved—namely, small-scale, politically decentralized societies (for notable exceptions, see here, here, and here). Most studies of punishment rely on participants from large-scale societies or, if they include participants from small-scale societies, on artificial experiments such as economic games.

In a recent paper, Manvir Singh and I examine the concrete enactment of punishment in three small-scale societies: Kiowa bison hunters (North America), Mentawai horticulturalists (Indonesia), and Nuer pastoralists (South Sudan). We code ethnographic reports of 91 offenses among the Kiowa, analyze first-hand interviews about 276 offenses among the Mentawai, and review punitive procedures documented among the Nuer.

With find that punitive procedures are often inconsistent with a norm-enforcement function. Most notably, people don’t bother punishing violations that don’t harm them directly. The quasi-totality of the punishments we observe, whether they involve fines, killing the offender, or destroying their property, are administered by the victim themselves or their family in retaliation for the harm suffered. Contrary to the idea that third-party punishment is universal and has shaped the evolution of human cooperation, people often seem indifferent to transgressions that do not affect them directly, even for serious transgressions such as murder.

If people do not punish to enforce collective norms or group cooperation, then what is punishment for? A useful analogy here is the distinction, made in some large-scale societies, between criminal law and civil law. Criminal law deals with violations of the society’s norms, which are punished by third-party officials on behalf of society as a whole. Civil law, by contrast, deals with dyadic disputes between private parties, requiring the offender to compensate the victim for the tort inflicted. Punitive justice in small-scale societies, we argue, serves only the civil function of resolving private disputes between offender and victim and restoring their cooperative relationship that was broken by the offense.

Offenses such as theft, murder, or adultery typically trigger retaliation on the part of the victim—a behavior evolved to deter future exploitation. Yet unrestrained retaliation can trigger counter-punishment on the part on of offender, which risks escalating into destructive feuds that end up harming not only disputants themselves, but also their kin or allies, who often get embroiled in the conflict. People have thus had a mutual interest in designing and retaining punitive procedures that seemed well-suited to reconciling disputants and limiting conflict between offender and victim after offenses.

Our results show that the justice systems of the Kiowa, the Mentawai, and the Nuer exhibit many features consistent with this restorative function. First, punishment was entangled with compensation: the offender had to pay costs, yes, but often while providing the victim with material benefits such as pigs, cattle, horses, or other valuables. This allows the victim to experience forgiveness and appeases their urge for revenge, preventing harsh retaliations that could spark destructive feuds. Second, the prescribed level of punishment and compensation was proportionate to the tort inflicted on the victim. This, again, is well suited to satisfy the victim’s urge for revenge while avoiding disproportionate retaliation that could spark counter-revenge. Third, while third parties rarely punished, they often intervened to mediate, pacify disputants, and help them achieve peaceful resolution.

Our results echo longstanding observations of legal anthropologists. For decades, researchers working in small-scale, politically decentralized societies have insisted on the rarity of third-party punishment, the private nature of law, and the compensatory logic of justice. Yet these features of punishment have been largely ignored by evolutionary social scientists and psychologists, leading to misleading assumptions about the evolution of punishment and cooperation. Rather than third-party punishers enforcing cooperation, as often occurs in large-scale, anonymous societies, social order in most human societies may have been far more decentralized, emerging from individuals and families negotiating over how to best treat each other.

Read the original paper: Fitouchi, L., & Singh, M. (2023). Punitive justice serves to restore reciprocal cooperation in three small-scale societies. Evolution & Human Behavior, 44(5), 502-514.

Long-distance friends are good friends to have around

– by Kristopher Smith

(Image description: Women in a Tanzanian fishing village “planting” shared algae lines during low tide.)

Long-distance relationships, whether they be friends, family, or colleagues, are found across the world. And while you might think that long-distance relationships are products of planes, phones, or the internet, long-distance relationships have actually long been an important component of human sociality. For example, obsidian trade networks in East Africa stretching hundreds of kilometers indicate humans were maintaining long-distance relationships as early as 700,000 years ago. Why do people bother being friends with people who live so far away from them?

Friends are one strategy people use to manage risk. Life is unpredictable, and while today you might be well-fed and in good health, tomorrow you might find your fortunes down. Friends help deal with this uncertainty by providing help to one another during down times, giving each other support whenever they need it, regardless of who helped whom last – that is, engaging in need-based sharing. Tracking debts between close-distance friends is a faux pas across cultures, and friends are expected to help each other as long as they are able to help–denying help because a previous act of support has not been reciprocated can be a quick way to end a friendship. Need-based helping is more robust compared to tit-for-tat reciprocity; if friends only helped each other when they can be paid back, then when someone was most in need of help, their friend would be unwilling to help due to concerns of not being repaid. By always helping each other when one of them is in need, friends can be assured they have the support to get through hard times.

But risks in the environment are often clustered in time and space, hitting everyone in a given area at the same time. In these cases, close-distance friends might not be able to provide help. For example, if you are a fisherman depending on a daily catch to feed your family, a large storm that stops you from going out to the ocean for days can spell trouble. And your friends might literally be in the same boat, unable to help you because they too need help. However, if you have friends further down the coast where the storm has not hit, you can reach out to them for support. In other words, long-distance friends are useful for providing access to resources not available in your local environment. Even when times are good, these friends can get you resources you cannot get locally, such as a place to stay while traveling or information about job opportunities in another city.

While long-distance friends can be useful for supplementing help from close-distance friends by providing access to non-local resources, they also present additional challenges. First, long-distance friends are seen less frequently. This makes it harder to monitor whether a friend is declining to help because they are intentionally refusing to help–and thus defecting on their cooperative partner–or are simply unable to help at the time. Second, they are unlikely to belong to the same cooperative institutions, which among close-distance friends can help smooth over disagreements and provide outside enforcement of cooperative agreements. For example, when friends attend the same religious congregation, they can appeal to their religious leader to mediate conflict between them, such as by reminding a stingy friend of the virtue of helping. Taken together, it is easier for long-distance friends to cheat the need-based sharing common among friends, and it is harder to encourage them to help via institutions. As a result, long-distance friends may be less likely to rely on need-based sharing and more carefully track debts between each other, only providing help when accounts are nearly balanced between each other.

Rural villages along the coast of the Western Indian Ocean in Tanzania primarily rely on small-scale fishing for their food and income. The productivity of different fishing spots changes across seasons, and to access better fishing spots, fishermen must travel to different villages, where they meet and befriend locals. Other professions connected to fisheries, such as fish processors and fishmongers, also travel to where business is booming, forming useful relationships beyond their home villages. As a result of people following the fish, they build a sprawling network of long-distance friendships between villages. Do these long-distance friends provide the same kind of need-based support as friends living in the same village?

To answer this, my collaborators and I interviewed 917 people in 21 fishing villages in the Tanga Region of Tanzania, asking participants about their friendships in their village and neighboring villages. We randomly chose one friend in their village and one friend in another village to ask about different kinds of help the participant had received from each friend, such as advice, loaned tools, and cash help in the form of loans and gifts. Loans and gifts offer interesting insight into account keeping because loans have an explicit expectation that the help is repaid in the future–it is literally tracking debts between friends, which is usually not the case for gifts.

Unsurprisingly, people were more likely to receive help in general from close-distance than long-distance friends. However, contrary to our prediction, long-distance friends were actually a little less likely to give loans than gifts, while close-distance friends were a little more likely to give loans than gifts. Long-distance friends did give larger loans than gifts, which at first glance is consistent with our predictions, but looking at why these loans were given revealed that long-distance friends were much more likely to give a loan for business investments compared to close-distance friends. And help as a business investment was the largest kind of help given, for both loans and gifts and for close- and long-distance friends. That is, long-distance friends are often providing loans for big-ticket items like new boats or ring nets. In many of these villages, that kind of cash is just not available to give out, and people are likely piecing together investments from their wider social network, receiving support that is unavailable locally.

While there were some differences between close- and long-distance friends, more notable was the similarity between them. Regardless of distance, the biggest kinds of help given by friends was advice, help when sick, and help with getting work done. And even among cash help, the differences between close- and long-distance friends were small. Previous research on long-distance relationships have focused on ritual relationships, such as osotua among the Maasai, where social and supernatural sanctions help reinforce the cooperative relationships, making them robust sources of support. Here, even among friendships with no special status, distance does not impede support flowing freely between friends.

The fact that long-distance friends provide the same quality support as close-distance friends has important implications for cooperation more broadly. Many collective action projects, such as managing open-access fisheries, require people to cooperate at a distance with people living in other communities. This can be a hard obstacle to overcome. Just like cooperation between friends, difficulty in monitoring others and lack of shared institutions can breed a lack of trust and interest in cooperating with people who live in other communities, causing between-community collective action efforts to fail. But if long-distance friends provide support to one another, then this can foster interdependence between them–their fortunes are tied together, such that a person providing help to their friend indirectly benefits because their friend is more able to help them in the future. This interdependence makes it more likely for them to participate in between-community collective action because of their mutual benefits from it. Long-distance friends then can be a foundation to build-up larger cooperative efforts, bridging communities with their shared interest, an idea my collaborators and I are currently testing in this context.

A friend in need is a friend indeed. And as it turns out, this is true regardless of whether your friend is your neighbor or lives a world away. People lean on their friends to get through hard times and long-distance friends can provide some kinds of help that close-distance friends might not be able to provide, no strings attached.

Read the original article: Smith, K.M., Pisor, A.C., Aron, B., Bernard, K., Fimbo, P., Kimesera, R., & Borgerhoff Mulder, M. (2023). Friends near and afar, through thick and thin: comparing contingency of help between close-distance and long-distance friends in Tanzanian fishing villages. Evolution & Human Behavior, 44(5), 454-465.

Learning Evolution & Games conference

The Learning, Evolution and Games 2024 conference will take place in Brisbane in July 2024. The LEG conferences bring together researchers who are interested in the evolutionary foundations of economic and social behaviour, evolutionary game theory, and learning in games.
Location: Queensland University of Technology, Brisbane
Time: 8-9 July 2024
Keynote speakers:

Ingela Alter (Toulouse)
Nichola Raihani (UCL)
You are most welcome to submit your papers and participate to the conference. In addition to the LEG conference, two other associated events will take place shortly before in Brisbane and Sydney.
Twinned conference: FUR 2024 conference
Since 1982, FUR gathers every two years researchers in economics, psychology and other behavioural sciences interested in the study of decision-making. For the first time of its history, FUR will take place in the Asia Pacific area in 2024.
Location: University of Queensland
Time: 3-6 July
 
Keynote speakers:
We are glad to announce a great list of speakers for the conference:
Ingela Alter (Toulouse)
Paul Glimcher (NYU)
John Quah (JHU-NUS)
John Quiggin (UQ)
Nichola Raihani (UCL)
Michael Woodford (Columbia)
Pre-conference workshop: Neuroeconomics of disadvantage
Location: University of Sydney
Time: 27-28 June
We look forward to receiving your submissions and seeing you in Brisbane!
Lionel Page
Behavioural and Economic Science Cluster
School of Economics

Evolutionary faculty job in Oklahoma

Oklahoma State University’s Psychology Department has a faculty position available in social neuroscience and/or evolutionary approaches to social behavior. Join the existing group of evolutionary researchers at the Oklahoma Center for Evolutionary Analysis (OCEAN)! Applications due Nov 1st.

See here for more information: https://apply.interfolio.com/134660

Tit for tattling: Communication, cooperation, and how each could stabilize the other

– by Victor Vikram Odouard

Driving my Fiat 500 convertible through the Swiss countryside surrounding Geneva, a sign caught my eye. In large hand written letters, it read “CAiSSE” – “CHeCKOUT” in French. Behind the sign, a heap of pumpkins lay on a threadbare canvas blanket. But unlike most checkouts, no one was there. And unlike most self-checkouts, there were no cameras in sight. No, this little Hofladen relied on the honor system.

Why wasn’t there a horde of pumpkin bandits raiding our humble farmstand?

Scientists have proposed many mechanisms to explain the evolution of altruistic behavior, such as kin altruism, punishment, and direct & indirect reciprocity. These all share a common characteristic: they provide a second-order benefit to altruists, that compensates for the initial cost.

Most of these mechanisms require knowledge of who is cooperating (I will sometimes call altruistic behavior cooperation in this post). Sometimes that knowledge can come from observation, as is the case with reciprocity (I know who did me a favor in the past). But other mechanisms, like third party punishment and indirect reciprocity, require that knowledge of who has cooperated spread to those who were unlikely to observe the interactions in question. This requires a faithful communication system (read: gossip!) that accurately transmits the relevant information.

And here we arrive at the question we pose in this paper: why should we even have such a communication system, when it might be in people’s interests to lie?

The question echoes the original cooperation question – “why should people benefit society by acting altruistically when it can come at a personal cost?” Here, we simply replace “acting altruistically” with “communicating truthfully”. The parallel points to a solution – perhaps the same mechanism that keeps people cooperative can also keep people communicative.

In our paper, we analyze a model of indirect reciprocity to determine whether such a mechanism can exist. Imagine an agent, Ariel. She meets someone else, Blake, and she can make a choice: she can cooperate or defect. If Ariel cooperates, she pays a cost in order to produce a benefit for Blake. Let’s say she does cooperate. Afterwards, Blake can “gossip” about Ariel’s behavior, in this case, “Ariel good”, since she cooperated. In the next interaction, when Ariel meets Corina, and Corina is deciding whether to cooperate with Ariel, Corina is aware of Blake’s gossip – in this case, that Ariel cooperated. Blake’s gossiping thus produces Ariel’s reputation. Corina can then, for example, decide to cooperate with Ariel since she cooperated with Blake. This is indirect reciprocity.

The twist in our model is that the indirect reciprocity “twists back” on itself: instead of reputations being based solely on how agents act, they can also be based on how agents gossip. How does this work? Returning to our previous scenario, let’s say Ariel cooperates with Blake, but Blake nonetheless says that “Ariel bad”. Perhaps someone, Diana, saw the whole thing go down, and she communicates “Blake bad”, because he lied. In Blake’s next interaction, with Ed, Ed could therefore decide not to cooperate with Blake.

In this scenario, the machinery being used to maintain cooperation (accurate communication) is being co-opted to maintain itself! In our paper, we ask whether such a self-referential system can actually lead to a stable, high-cooperation state, and we found that yes, it could, in the case where (1) agents made occasional (but not too frequent) errors and (2) the norm punishes defection while nonetheless being self-consistent. Both of these conditions will require further explanation.

The first condition reflects an important fact about many complex systems, which is that heterogeneity can enhance stability: for instance, a virus often has a harder time sweeping through a population with many diverse immune responses to its infection, as it must circumvent many different types of defenses. Taking this one step further, if a population has been infected by many different sorts of viruses in the past, it can mount a diversity of different immune responses to any new pathogen – thus, a diversity of past “disturbances” (viruses, in this case), can make a population more robust by diversifying its immune defenses. This is exactly what we see in our model, where error introduces diversity by causing, for instance, some defections, or some untruthful gossip, where they wouldn’t usually occur. We found that this diversity of small-scale disturbances inoculates the system against more serious destabilizing forces.

As for the second condition, a norm in our setting is a determination of whether a given action is good or bad. A gossip system can encode such a norm: for instance, it might call cooperation and truthfulness “good” and defection and untruthfulness “bad”. Agents can then respond to those judgments: for instance, in one of the above examples, Blake was deemed “bad” for having lied about Ariel, and Diana therefore refused to cooperate with him. But a question arises: does the norm judge Diana’s action, which is in effect enforcing the norm (cooperating with those who followed the truthfulness norm, defecting with those who didn’t), as good? In this simple case, no – defection is considered bad. So Diana is judged as “bad” under the very norm that she is enforcing! This norm is therefore not self-consistent – a norm is self-consistent if it does reward the actions enforcing it. A self-consistent norm instead might deem cooperating with “good” agents good, and defecting with “bad” agents good, and everything else “bad”. This norm, called stern judging, is self-consistent, because it rewards the behaviors that enforce it. For instance, there are some societies that consider theft to be permissible if committed against people in bad standing in the community (for instance, people who unjustifiably stole from someone else). This is a self-consistent norm, as the punishment of individuals in bad standing is permissible under the norm’s own rules.

In our analysis, we find that maintenance of cooperation and communication requires such a self-consistent norm. This highlights that for decentralized norm enforcement, self-consistency is critical. If norm enforcement is centralized, self-consistency need not apply, as different rules may exist for judging the centralized body of enforcers and everyone else. For instance, most people judge killing to be bad, but in some countries, this judgment does not apply to a government doling out the death penalty. However, with decentralized norm enforcement, the people who enforce the norms are the people, and therefore no such distinction can exist. Self-consistency is thus needed.

Our study is fundamentally about whether a self-contained norm-enforcement system, not buttressed by anything external, can maintain high levels of cooperation. The external buttress that provoked our study was communication – most indirect reciprocity models assume an already-truthful communication system. But by noticing here that communicating truthfully is not so different from cooperating (in that both provide a public good), we hypothesized that the same indirect reciprocity mechanism enforcing cooperation could enforce truthful communication, without relying on a preexisting communication. The two conditions under which such a state was stable emphasize other important properties of a self-contained norm enforcement system. First, that it can “create its own diversity”, through error, allowing the system to function without being propped up by some external source of diversity. And second, that the norm is able to “reward its own enforcers”, by being self-consistent – this allows enforcement to occur without requiring a separate body of enforcers, operating under different rules.

Read the original article: Odouard, V.V., & Price, M.H. (2023). Tit for tattling: cooperation, communication, and how each could stabilize the other. Evolution & Human Behavior, 44(4), 359-372.