Are we there yet? Every computational theory needs a few black boxes, including theories about groups.

Pietraszewski exemplifies the need for computational theory using group conflict; I complement this with an example of group cooperation. He criticizes past theories for having black boxes; I suggest his theory also has a black box - the concept of costs. He divides what mentally constitutes a group from mere ancillary attributes; I hazard that some of these attributes are essential.

Beyond market behavior: Evolved cognition and folk political economic beliefs.

Boyer & Petersen (B&P) lay out a compelling theory for folk-economic beliefs, focusing on beliefs about markets. However, societies also allocate resources through mechanisms involving power and group decision-making (e.g., voting), through the political economy. We encourage future work to keep folk political economic beliefs in mind, and sketch an example involving pollution and climate change mitigation policy.

Looking Under the Hood of Third-Party Punishment Reveals Design for Personal Benefit.

Third-party intervention, such as when a crowd stops a mugger, is common. Yet it seems irrational because it has real costs but may provide no personal benefits. In a laboratory analogue, the third-party-punishment game, third parties ("punishers") will often spend real money to anonymously punish bad behavior directed at other people. A common explanation is that third-party punishment exists to maintain a cooperative society. We tested a different explanation: Third-party punishment results from a deterrence psychology for defending personal interests. Because humans evolved in small-scale, face-to-face social worlds, the mind infers that mistreatment of a third party predicts later mistreatment of oneself. We showed that when punishers do not have information about how they personally will be treated, they infer that mistreatment of other people predicts mistreatment of themselves, and these inferences predict punishment. But when information about personal mistreatment is available, it drives punishment. This suggests that humans' punitive psychology evolved to defend personal interests.

The sketch is blank: No evidence for an explanatory role for cultural group selection.

As evidence that cultural group selection has occurred, Richerson et al. simply retrodict that humans use language, punish each other, and have religion. This is a meager empirical haul after 30 years. This contrasts sharply with the adaptationist approach to human behavior - evolutionary psychology - which has produced scores of novel, specific, and empirically confirmed predictions.

Evolution of direct reciprocity under uncertainty can explain human generosity in one-shot encounters.

Are humans too generous? The discovery that subjects choose to incur costs to allocate benefits to others in anonymous, one-shot economic games has posed an unsolved challenge to models of economic and evolutionary rationality. Using agent-based simulations, we show that such generosity is the necessary byproduct of selection on decision systems for regulating dyadic reciprocity under conditions of uncertainty. In deciding whether to engage in dyadic reciprocity, these systems must balance (i) the costs of mistaking a one-shot interaction for a repeated interaction (hence, risking a single chance of being exploited) with (ii) the far greater costs of mistaking a repeated interaction for a one-shot interaction (thereby precluding benefits from multiple future cooperative interactions). This asymmetry builds organisms naturally selected to cooperate even when exposed to cues that they are in one-shot interactions.

When the economy falters, do people spend or save? Responses to resource scarcity depend on childhood environments.

Just as modern economies undergo periods of boom and bust, human ancestors experienced cycles of abundance and famine. Is the adaptive response when resources become scarce to save for the future or to spend money on immediate gains? Drawing on life-history theory, we propose that people's responses to resource scarcity depend on the harshness of their early-life environment, as reflected by childhood socioeconomic status (SES). In the three experiments reported here, we tested how people from different childhood environments responded to resource scarcity. We found that people who grew up in lower-SES environments were more impulsive, took more risks, and approached temptations more quickly. Conversely, people who grew up in higher-SES environments were less impulsive, took fewer risks, and approached temptations more slowly. Responses similarly diverged according to people's oxidative-stress levels-a urinary biomarker of cumulative stress exposure. Overall, whereas tendencies associated with early-life environments were dormant in benign conditions, they emerged under conditions of economic uncertainty.

Is a Rational Politics of Disaster Possible? Making Useful Decisions for Others in an Experimental Disaster Game.

Disaster responses are political. But can citizens make useful disaster decisions? Potential obstacles are that such decisions are complex, involve public goods, and often affect other people. Theories of political decision-making disagree on whether these problems can be overcome. We used experimental economic games that simulate disaster to test whether people are willing and able to prevent disasters for others. Groups of players face a complex task in which options that might help vary in their riskiness. Importantly, although all options are reasonable, which option is most useful depends on the experimental condition. We find that players will pay to help, can identify which option is most useful across experimental conditions, and will pay to learn how best to help. Thus, players were able to make useful and costly decisions to prevent others from experiencing disaster. This suggests that, in at least some situations, citizens may be able to make good disaster decisions. Supplementary Information: The online version contains supplementary material available at 10.1007/s11109-021-09700-2.

The Social Cognition of Social Foraging: Partner Selection by Underlying Valuation.

Humans and other animals have a variety of psychological abilities tailored to the demands of asocial foraging, that is, foraging without coordination or competition with other conspecifics. Human foraging, however, also includes a unique element, the creation of resource pooling systems. In this type of social foraging, individuals contribute when they have excess resources and receive provisioning when in need. Is this behavior produced by the same psychology as asocial foraging? If so, foraging partners should be judged by the same criteria used to judge asocial patches of resources: the net energetic benefits they provide. The logic of resource pooling speaks against this. Maintaining such a system requires the ability to judge others not on their short-term returns, but on the psychological variables that guide their behavior over the long-term. We test this idea in a series of five studies using an implicit measure of categorization. Results showed that (1) others are judged by the costs they incur (a variable not relevant to asocial foraging) whereas (2) others are not judged by the benefits they provide when benefits provided are unrevealing of underlying psychological variables (despite this variable being relevant to asocial foraging). These results are suggestive of a complex psychology designed for both social and asocial foraging.

The future-orientation of memory: planning as a key component mediating the high levels of recall found with survival processing.

In a series of papers, Nairne and colleagues have demonstrated that tasks encouraging participants to judge words for relevance to survival led to better recall than did tasks lacking survival relevance. Klein, Robertson, and Delton (2010) presented data suggesting that the future-directed temporal orientation of the survival task (e.g., planning), rather than survival per se, accounts for the good recall found with the task. In the present studies we manipulated the amount of survival and planning processing encouraged by a set of encoding tasks. Participants performed tasks that encouraged processing stimuli for their relevance to (a) both survival and planning, (b) planning, but not survival, or (c) survival but not planning. We predicted, and found, that recall performance associated with tasks encouraging planning (i.e., survival with planning and planning without survival) should exceed tasks that encouraged survival but not planning (i.e., survival without planning). We draw several conclusions. First, planning is a necessary component of the superior recall found in the survival paradigm. Second, memory, from an evolutionary perspective, is inherently prospective--tailored by natural selection to support future decisions and judgements that cannot be known in advance with certainty.

Facing the future: memory as an evolved system for planning future acts.

All organisms capable of long-term memory are necessarily oriented toward the future. We propose that one of the most important adaptive functions of long-term episodic memory is to store information about the past in the service of planning for the personal future. Because a system should have especially efficient performance when engaged in a task that makes maximal use of its evolved machinery, we predicted that future-oriented planning would result in especially good memory relative to other memory tasks. We tested recall performance of a word list, using encoding tasks with different temporal perspectives (e.g., past, future) but a similar context. Consistent with our hypothesis, future-oriented encoding produced superior recall. We discuss these findings in light of their implications for the thesis that memory evolved to enable its possessor to anticipate and respond to future contingencies that cannot be known with certainty.

Are Humans Too Generous and Too Punitive? Using Psychological Principles to Further Debates about Human Social Evolution.

Are humans too generous and too punitive? Many researchers have concluded that classic theories of social evolution (e.g., direct reciprocity, reputation) are not sufficient to explain human cooperation; instead, group selection theories are needed. We think such a move is premature. The leap to these models has been made by moving directly from thinking about selection pressures to predicting patterns of behavior and ignoring the intervening layer of evolved psychology that must mediate this connection. In real world environments, information processing is a non-trivial problem and details of the ecology can dramatically constrain potential solutions, often enabling particular heuristics to be efficient and effective. We argue that making the intervening layer of psychology explicit resolves decades-old mysteries in the evolution of cooperation and punishment.

Functional projection: how fundamental social motives can bias interpersonal perception.

Results from 2 experimental studies suggest that self-protection and mate-search goals lead to the perception of functionally relevant emotional expressions in goal-relevant social targets. Activating a self-protection goal led participants to perceive greater anger in Black male faces (Study 1) and Arab faces (Study 2), both out-groups heuristically associated with physical threat. In Study 2, participants' level of implicit Arab-threat associations moderated this bias. Activating a mate-search goal led male, but not female, participants to perceive more sexual arousal in attractive opposite-sex targets (Study 1). Activating these goals did not influence perceptions of goal-irrelevant targets. Additionally, participants with chronic self-protective and mate-search goals exhibited similar biases. Findings are consistent with a functionalist, motivation-based account of interpersonal perception.

Group Cooperation without Group Selection: Modest Punishment Can Recruit Much Cooperation.

Humans everywhere cooperate in groups to achieve benefits not attainable by individuals. Individual effort is often not automatically tied to a proportionate share of group benefits. This decoupling allows for free-riding, a strategy that (absent countermeasures) outcompetes cooperation. Empirically and formally, punishment potentially solves the evolutionary puzzle of group cooperation. Nevertheless, standard analyses appear to show that punishment alone is insufficient, because second-order free riders (those who cooperate but do not punish) can be shown to outcompete punishers. Consequently, many have concluded that other processes, such as cultural or genetic group selection, are required. Here, we present a series of agent-based simulations that show that group cooperation sustained by punishment easily evolves by individual selection when you introduce into standard models more biologically plausible assumptions about the social ecology and psychology of ancestral humans. We relax three unrealistic assumptions of past models. First, past models assume all punishers must punish every act of free riding in their group. We instead allow punishment to be probabilistic, meaning punishers can evolve to only punish some free riders some of the time. This drastically lowers the cost of punishment as group size increases. Second, most models unrealistically do not allow punishment to recruit labor; punishment merely reduces the punished agent's fitness. We instead realistically allow punished free riders to cooperate in the future to avoid punishment. Third, past models usually restrict agents to interact in a single group their entire lives. We instead introduce realistic social ecologies in which agents participate in multiple, partially overlapping groups. Because of this, punitive tendencies are more expressed and therefore more exposed to natural selection. These three moves toward greater model realism reveal that punishment and cooperation easily evolve by direct selection--even in sizeable groups.

Prosocial effects of MDMA: A measure of generosity.

BACKGROUND: 3,4-methylenedioxymethamphetamine (MDMA) produces "prosocial" effects that contribute to its recreational use. Few studies have examined the cognitive and behavioral mechanisms by which MDMA produces these effects. Here we examined the effect of MDMA on a specific prosocial effect, i.e. generosity, using a task in which participants make decisions about whether they or another person will receive money (Welfare Trade-Off Task; WTT). METHODS: The project included one study without drug administration and one with MDMA. In Study 1, we administered the WTT to healthy adults (N = 361) and examined their performance in relation to measures of personality and socioeconomic status. In Study 2, healthy volunteers with MDMA experience (N = 32) completed the WTT after MDMA administration (0, 0.5, or 1.0 mg/kg). RESULTS: As expected, in both studies participants were more generous with a close friend than an acquaintance or stranger. In Study 1, WTT generosity was related to household income and trait Agreeableness. In Study 2, MDMA (1.0 mg/kg) increased generosity toward a friend but not a stranger, whereas MDMA (0.5 mg/kg) slightly increased generosity toward a stranger, especially among female participants. CONCLUSIONS: These data indicate that the WTT is a valuable, novel tool to assess a component of prosocial behavior, i.e. generosity to others. The findings support growing evidence that MDMA produces prosocial effects, but, as with oxytocin, these appear to depend on the social proximity of the relationships. The brain mechanisms underlying the construct of generosity, or the effects of MDMA on this measure, remain to be determined.

Sexually selective cognition: beauty captures the mind of the beholder.

Across 5 experimental studies, the authors explore selective processing biases for physically attractive others. The findings suggest that (a). both male and female observers selectively attend to physically attractive female targets, (b). limiting the attentional capacity of either gender results in biased frequency estimates of attractive females, (c). although females selectively attend to attractive males, limiting females' attentional capacity does not lead to biased estimates of attractive males, (d). observers of both genders exhibit enhanced recognition memory for attractive females but attenuated recognition for attractive males. Results suggest that different mating-related motives may guide the selective processing of attractive men and women.

The Co-evolution of Concepts and Motivation.

Does the human mind contain evolved concepts? Many psychologists have doubted this or have investigated only a narrow set (e.g., object, number, cause). Does the human mind contain evolved motivational systems? Many more assent to this claim, holding that there are evolved motivational systems for, among other tasks, social affiliation, aggressive competition, and finding food. An emerging research program, however, reveals that these are not separate questions. Any evolved motivational system needs a wealth of conceptual structure that tethers the motivations to real world entities. For instance, what use is a fear of predators without knowing what predators are and how to respond to them effectively? As we illustrate with case studies of cooperation and conflict, there is no motivation without representation: To generate adaptive behavior, motivational systems must be interwoven with the concepts required to support them, and cannot be understood without explicit reference to those concepts.

Meeting now suggests we will meet again: implications for debates on the evolution of cooperation.

Humans are often generous, even towards strangers encountered by chance and even in the absence of any explicit information suggesting they will meet again. Because game theoretic analyses typically conclude that a psychology designed for direct reciprocity should defect in such situations, many have concluded that alternative explanations for human generosity--explanations beyond direct reciprocity--are necessary. However, human cooperation evolved within a material and informational ecology: Simply adding consideration of one minimal ecological relationship to the analysis of reciprocity brings theory and observation closer together, indicating that ecology-free analyses of cooperation can be fragile. Using simulations, we show that the autocorrelation of an individual's location over time means that even a chance encounter with an individual predicts an increased probability of a future encounter with that same individual. We discuss how a psychology designed for such an ecology may be expected to often cooperate even in apparently one-shot situations.

Merely opting out of a public good is moralized: an error management approach to cooperation.

People regularly free ride on collective benefits, consuming them without contributing to their creation. In response, free riders are often moralized, becoming targets of negative moral judgments, anger, ostracism, or punishment. Moralization can change free riders' behavior (e.g., encouraging them to contribute or discouraging them from taking future benefits) or it can motivate others, including moralizers, to avoid or exclude free riders; these effects of moralization are critical to sustaining human cooperation. Based on theories of error management and fundamental social domains from evolutionary psychology, we propose that the decision to moralize is a cue-driven process. One cue investigated in past work is observing a person illicitly consume collective benefits. Here, we test whether the mind uses a 2nd cue: merely opting out of contributing. Use of this cue creates a phenomenon of preventive moralization: moralization of people who have not yet exploited collective benefits but who might-or might not--in the future. We tested for preventive moralization across 9 studies using implicit and explicit measures of moralization, a behavioral measure of costly punishment, mediation analyses of the underlying processes, and a nationally representative sample of almost 1,000 U.S. adults. Results revealed that merely opting out of contributing to the creation of exploitable collective benefits--despite not actually exploiting collective benefits-elicited moralization. Results further showed that preventive moralization is not due to the moralization of selfishness or deviance but instead follows from the uncertainty inherent in moralization decisions. These results imply that even people who will never exploit collective benefits can nonetheless be targets of moralization. We discuss implications for social and political dynamics.

Familiarity and personal experience as mediators of recall when planning for future contingencies.

In this article, we demonstrate that planning tasks enhance recall when the context of planning (a) is self-referential and (b) draws on familiar scenarios represented in episodic memory. Specifically, we show that when planning tasks are sorted according to the degree to which they evoke memories of personally familiar scenarios (e.g., planning a picnic), recall is reliably superior to tasks that fail to do so (e.g., planning an Arctic trek). We discuss the implications of these findings for planning tasks and their relation to episodic memory.

The psychosemantics of free riding: dissecting the architecture of a moral concept.

For collective action to evolve and be maintained by selection, the mind must be equipped with mechanisms designed to identify free riders--individuals who do not contribute to a collective project but still benefit from it. Once identified, free riders must be either punished or excluded from future collective actions. But what criteria does the mind use to categorize someone as a free rider? An evolutionary analysis suggests that failure to contribute is not sufficient. Failure to contribute can occur by intention or accident, but the adaptive threat is posed by those who are motivated to benefit themselves at the expense of cooperators. In 6 experiments, we show that only individuals with exploitive intentions were categorized as free riders, even when holding their actual level of contribution constant (Studies 1 and 2). In contrast to an evolutionary model, rational choice and reinforcement theory suggest that different contribution levels (leading to different payoffs for their cooperative partners) should be key. When intentions were held constant, however, differences in contribution level were not used to categorize individuals as free riders, although some categorization occurred along a competence dimension (Study 3). Free rider categorization was not due to general tendencies to categorize (Study 4) or to mechanisms that track a broader class of intentional moral violations (Studies 5A and 5B). The results reveal the operation of an evolved concept with features tailored for solving the collective action problems faced by ancestral hunter-gatherers.