Pat Barclay

Partner choice creates competitive altruism in humans

Reciprocal altruism has been the backbone of research on the evolution of altruistic behaviour towards non-kin, but recent research has begun to apply costly signalling theory to this problem. In addition to signalling resources or abilities, public generosity could function as a costly signal of cooperative intent, benefiting altruists in terms of (i) better access to cooperative relationships and (ii) greater cooperation within those relationships. When future interaction partners can choose with whom they wish to interact, this could lead to competition to be more generous than others. Little empirical work has tested for the possible existence of this ‘competitive altruism’. Using a cooperative monetary game with and without opportunities for partner choice and signalling cooperative intent, we show here that people actively compete to be more generous than others when they can benefit from being chosen for cooperative partnerships, and the most generous people are correspondingly chosen more often as cooperative partners. We also found evidence for increased scepticism of altruistic signals when the potential reputational benefits for dishonest signalling were high. Thus, this work supports the hypothesis that public generosity can be a signal of cooperative intent, which people sometimes ‘fake’ when conditions permit it.

Do people differentially remember cheaters

The evolution of reciprocal altruism probably involved the evolution of mechanisms to detect cheating and remember cheaters. In a well-known study, Mealey, Daood, and Krage (1996) observed that participants had enhanced memory for faces that had previously been associated with descriptions of acts of cheating. There were, however, problems with the descriptions that were used in that study. We sought to replicate and extend the findings of Mealey and colleagues by using more controlled descriptions and by examining the possibility of enhanced altruist recognition. We also examined whether individual differences in cheating tendencies were related to cheater and altruist recognition. In the first experiment, 164 undergraduates saw 40 faces that were paired with character descriptions representing the categories of cheater, trustworthy, altruist, or neutral, for individuals who had either low or high social status. One week later participants reported which faces they recognized from the previous week (among 80 faces). Overall, the results failed to replicate the findings of Mealey and her colleagues, as there was no enhanced memory for cheaters. In addition, there was no enhanced memory for altruists, and no effect of participants’ cheating tendencies. A second experiment using a slightly different methodology produced similar results, with some evidence for enhanced memory for altruists.

Competitive helping increases with the size of biological markets and invades defection

Cooperation between unrelated individuals remains a puzzle in evolutionary biology. Recent work indicates that partner choice can select for high levels of helping. More generally, helping can be seen as but one strategy used to compete for partners within a broader biological market, yet giving within such markets has received little mathematical investigation. In the present model, individuals help others to attract attention from them and thus receive a larger share of any help actively or passively provided by those others. The evolutionarily stable level of helping increases with the size of the biological market and the degree of partner choice. Furthermore, if individuals passively produce some no-cost help to partners, competitive helping can then invade populations of non-helpers because helpers directly benefit from increasing their access to potential partners. This framework of competitive helping demonstrates how high helping can be achieved and why different populations may differ in helping levels.

Parasite stress and pathogen avoidance relate to distinct dimensions of political ideology across 30 nations

Significance Pathogens, and antipathogen behavioral strategies, affect myriad aspects of human behavior. Recent findings suggest that antipathogen strategies relate to political attitudes, with more ideologically conservative individuals reporting more disgust toward pathogen cues, and with higher parasite stress nations being, on average, more conservative. However, no research has yet adjudicated between two theoretical accounts proposed to explain these relationships between pathogens and politics. We find that national parasite stress and individual disgust sensitivity relate more strongly to adherence to traditional norms than they relate to support for barriers between social groups. These results suggest that the relationship between pathogens and politics reflects intragroup motivations more than intergroup motivations. People who are more avoidant of pathogens are more politically conservative, as are nations with greater parasite stress. In the current research, we test two prominent hypotheses that have been proposed as explanations for these relationships. The first, which is an intragroup account, holds that these relationships between pathogens and politics are based on motivations to adhere to local norms, which are sometimes shaped by cultural evolution to have pathogen-neutralizing properties. The second, which is an intergroup account, holds that these same relationships are based on motivations to avoid contact with outgroups, who might pose greater infectious disease threats than ingroup members. Results from a study surveying 11,501 participants across 30 nations are more consistent with the intragroup account than with the intergroup account. National parasite stress relates to traditionalism (an aspect of conservatism especially related to adherence to group norms) but not to social dominance orientation (SDO; an aspect of conservatism especially related to endorsements of intergroup barriers and negativity toward ethnic and racial outgroups). Further, individual differences in pathogen-avoidance motives (i.e., disgust sensitivity) relate more strongly to traditionalism than to SDO within the 30 nations.

Harnessing the Power of Reputation: Strengths and Limits for Promoting Cooperative Behaviors

Evolutionary approaches have done much to identify the pressures that select for cooperative sentiment. This helps us understand when and why cooperation will arise, and applied research shows how these pressures can be harnessed to promote various types of cooperation. In particular, recent evidence shows how opportunities to acquire a good reputation can promote cooperation in laboratory and applied settings. Cooperation can be promoted by tapping into forces like indirect reciprocity, costly signaling, and competitive altruism. When individuals help others, they receive reputational benefits (or avoid reputational costs), and this gives people an incentive to help. Such findings can be applied to promote many kinds of helping and cooperation, including charitable donations, tax compliance, sustainable and pro-environmental behaviors, risky heroism, and more. Despite the potential advantages of using reputation to promote positive behaviors, there are several risks and limits. Under some circumstances, opportunities for reputation will be ineffective or promote harmful behaviors. By better understanding the dynamics of reputation and the circumstances under which cooperation can evolve, we can better design social systems to increase the rate of cooperation and reduce conflict.

The Relative State Model Integrating Need-Based and Ability-Based Pathways to Risk-Taking

Who takes risks, and why? Does risk-taking in one context predict risk-taking in other contexts? We seek to address these questions by considering two non-independent pathways to risk: need-based and ability-based. The need-based pathway suggests that risk-taking is a product of competitive disadvantage consistent with risk-sensitivity theory. The ability-based pathway suggests that people engage in risk-taking when they possess abilities or traits that increase the probability of successful risk-taking, the expected value of the risky behavior itself, and/or have signaling value. We provide a conceptual model of decision-making under risk—the relative state model—that integrates both pathways and explicates how situational and embodied factors influence the estimated costs and benefits of risk-taking in different contexts. This model may help to reconcile long-standing disagreements and issues regarding the etiology of risk-taking, such as the domain-generality versus domain-specificity of risk or differential engagement in antisocial and non-antisocial risk-taking.

Who Cries Wolf, and When? Manipulation of Perceived Threats to Preserve Rank in Cooperative Groups

People perform greater within-group cooperation when their groups face external threats, such as hostile outgroups or natural disasters. Researchers and social commentators suggest that high-ranking group members manipulate this “threat-dependent” cooperation by exaggerating threats in order to promote cooperation and suppress competition for their position. However, little systematic research tests this claim or possible situational moderators. In three studies, we use a cooperative group game to show that participants pay to increase others’ perceptions of group threats, and spend more on manipulation when holding privileged positions. This manipulation cost-effectively elicits cooperation and sustains privilege, and is fostered by competition over position, not only position per se. Less cooperative people do more manipulation than more cooperative people do. Furthermore, these effects generalize to broader definitions of privilege. Conceptually, these results offer new insights into an understudied dimension of group behavior. Methodologically, the research extends cooperative group games to allow for analyzing more complex group dynamics.

Local competition sparks concerns for fairness in the ultimatum game

Humans reject uneven divisions of resources, even at personal cost. This is observed in countless experiments using the ultimatum game, where a proposer offers to divide a resource with a responder who either accepts the division or rejects it (whereupon both earn zero). Researchers debate why humans evolved a psychology that is so averse to inequity within partnerships. We suggest that the scale of competition is crucial: under local competition with few competitors, individuals reject low offers, because they cannot afford to be disadvantaged relative to competitors. If one competes against the broader population (i.e. global competition), then it pays to accept low offers to increase ones absolute pay-off. We support this intuition with an illustrative game-theoretical model. We also conducted ultimatum games where participants received prizes based on pay-offs relative to immediate partners (local competition) versus a larger group (global competition). Participants demanded higher offers under local competition, suggesting that local competition increases peoples demands for fairness and aversion to inequality.

Altruism predicts mating success in humans.

In order for non-kin altruism to evolve, altruists must receive fitness benefits for their actions that outweigh the costs. Several researchers have suggested that altruism is a costly signal of desirable qualities, such that it could have evolved by sexual selection. In two studies, we show that altruism is broadly linked with mating success. In Study 1, participants who scored higher on a self-report altruism measure reported they were more desirable to the opposite sex, as well as reported having more sex partners, more casual sex partners, and having sex more often within relationships. Sex moderated some of these relationships, such that altruism mattered more for mens number of lifetime and casual sex partners. In Study 2, participants who were willing to donate potential monetary winnings (in a modified dictator dilemma) reported having more lifetime sex partners, more casual sex partners, and more sex partners over the past year. Men who were willing to donate also reported having more lifetime dating partners. Furthermore, these patterns persisted, even when controlling for narcissism, Big Five personality traits, and socially desirable responding. These results suggest that altruists have higher mating success than non-altruists and support the hypothesis that altruism is a sexually selected costly signal of difficult-to-observe qualities.

Prosocial Behavior and Social Status

Humans are a very prosocial species, in that we often help others even at a cost to ourselves. Such behavior affects—and is affected by—a person’s social status. In the current chapter, we examine the interactions between social status and prosocial behavior, and we show that causation goes in both directions. On the one hand, laboratory and field evidence show that prosocial behavior can be a means of achieving, or maintaining, elevated status and accessing the accompanying material and social rewards. On the other hand, possessing status can also affect prosocial behavior (for better or worse) by altering the costs and benefits of prosociality, for example, by affecting people’s dependence on others, their vested interest in others, their ability to be prosocial, and their need for status maintenance. Status thus influences the use of prosocial behavior, but can increase it or decrease it depending on the context and the specific type of prosocial behavior. By understanding this bi-directional causation and applying it, we can harness people’s desire for status to promote prosocial behaviors by ensuring its visibility and by fostering competitive altruism.