Reputation of Those Who Cooperate Beyond Group Boundaries: A Comparison of Universalistic and In-Group Favoring Strategies

It has been suggested by various studies that between-group cooperation is more difficult to achieve than within-group cooperation. To investigate the factors that inhibit between-group cooperation, the reputation of a universalist, who cooperates beyond group boundaries, was considered. If the universalists were to be evaluated negatively, people would hesitate to cooperate beyond group boundaries. To examine this possibility, a comparison was drawn between the evaluation of people who employed the universalistic strategy and those who employed the in-group favoring strategy (who cooperates only with in-group members) by conducting a vignette experiment. In the experiment, participants evaluated two in-group members: one employed the in-group favoring strategy, and the other employed the universalistic strategy. In addition to the type of strategy, a trade-off between what in-group members received and what out-group members received was manipulated. Two studies were conducted by varying the universalistic strategy. The universalistic strategy meant giving resources equally to both group members in Study 1, and it meant maximizing the joint profit between the groups in Study 2. The results across the two studies suggest that the universalistic strategy was evaluated more positively than the in-group favoring strategy, with the exception that the in-group favoring strategy was chosen as the same group member in the future. Whether there was a trade-off had little effect on the evaluations of the two strategies. Consequently, this study suggests that the negative reputation of universalists might not be a factor that inhibited between-group cooperation.

Is Country-Level Extraversion Associated with the Number of COVID-19 Cases and Deaths?

An evolutionary explanation of between-country variation in extraversion assumes that it is more adaptive in the absence of pathogens but less adaptive in pathogen-prevalent environments. We attempted to test this assumption by correlating country-level extraversion scores and the number of COVID-19 cases and deaths. There are at least five country-level extraversion scores available, three of which were significantly correlated with the number of COVID-19 cases and two of which were significantly correlated with the number of COVID-19 deaths. This apparent partial support for the assumption is puzzling because the validity of country-level extraversion scores was low. Brief numerical simulations suggest that a statistical artefact due to combining two mutually non-independent subgroups (European/American countries and African/Asian countries) may account for the observed country-level correlations.

Inequality Biases Third-Party Evaluation of Decision-Making for Others

People often need to make risky decisions for others, especially in policymaking, where a single decision can affect the welfare of a number of people. Given that risky decisions can yield variable outcomes and that people often evaluate policies after knowing the outcomes, the same risky policy can be evaluated differently depending on its outcome. Nevertheless, very little is known about how people make third-party evaluations of risky policies. Because people are sensitive to inequality among others, we predicted that the same policy would be evaluated more negatively if it leads to inequality rather than other outcomes. To examine this, we conducted a scenario experiment on risky and sure policies and investigated whether people’s distributive preferences moderated policy evaluation. We show that participants rated the risky policy lower when it yielded unequal situations between the recipients. Interestingly, participants did not evaluate the risky policy higher than the sure policy even when the risky policy yielded more desirable outcomes. In addition, participants who preferred sure distributions as decision makers or recipients showed the inequality aversion, whereas participants who preferred risky distributions showed no such pattern. Our results suggest that policy evaluation may be susceptible to the risks and inequality of outcomes among recipients.

Intergroup Discrimination in Cooperation Among Moral and Non-Moral Groups

In-group favouritism is ubiquitous and previous studies have consistently found that individuals cooperate more with in-group members than out-group members in diverse contexts. Yet, there has not been much research on the role of the nature of groups in intergroup cooperation. A recent study found stronger levels of in-group favouritism amongst groups formed on the basis of shared moral values. However, it remained unclear whether the increased favouritism was caused by a greater tendency to act favourably towards the in-group or derogatorily towards the out-group. The present study thus investigated intergroup cooperation among morality-based and non-morality-based groups and examined the levels of cooperation with an in-group member and an out-group member as compared to a person whose group membership was unknown. Regardless of how groups were formed, in-group favouritism was present, while out-group derogation was absent. Furthermore, we found that the shared morality promoted in-group cooperation indirectly via low perceived out-group warmth. Our study provides further evidence that in-group favouring behaviour does not include derogating out-groups and points to the importance of further investigation into the role of the shared morality in intergroup cooperation.

Education as Niche Construction: Toward an Evolutionary Science of Education

In humans, education is characterized by active teaching in a wide range of knowledge domains. The subjects taught include how to think and behave, norms and morals, and knowledge and skills, all of which directly increase the fitness of the pupils. Although many comparative and developmental studies have examined active teaching in humans, few have considered its ultimate factors, especially its adaptive significance. The evolution of education can be considered in the context of the evolution of altruistic behavior because tutors transmit adaptive information to pupils at a cost. The evolution of altruism can be explained by the positive assortment of genes related to altruism. However, a genetic basis for reciprocity is not a necessary condition for the evolution of reciprocal altruism. Reciprocal altruism is possible without positive assortment if mutually beneficial social relationships can be created culturally through education. Active teaching of reciprocal norms could be interpreted as niche construction for a social environment. The adaptive perspective presented here could lead to an evolutionary science of education in the future.

Acetaminophen Potentiates Fear Processing: A Comparison Between Ancestral and Modern Threats

The painkilling medication acetaminophen produces a variety of unintended psychological effects. In particular, it has been shown to diminish varied forms of psychological distress by attenuating neural activity in the cerebral cortex and enhancing the signaling of serotonin. As a result, this over-the-counter medication appears to dampen overall affective processing and has been termed “an all-purpose emotion reliever.” However, this drug may not necessarily modify all emotions in the same manner. Specifically, fear processing occurs rapidly within the amygdala and is governed by serotonin. Thus, by blunting cortical activity and facilitating serotonergic action, acetaminophen could in fact potentiate reactions to threatening stimuli. This study intersects with the fields of evolutionary psychology and psychopharmacology by investigating whether acetaminophen modulates responses to fear-inducing stimuli that vary in ancestral relevance. We hypothesized that the more subcortical and prewired mechanisms controlling responses to recurring ancestral threats (snakes and spiders) would be more affected by this drug compared to learned threats of modern environments (handguns and hypodermic needles). In a double-blind placebo-controlled design (N = 94), acetaminophen significantly enhanced participants’ evaluations and emotional reactions to threatening stimuli. In addition, ancestral threats were rated as both significantly more negative and emotionally arousing compared to modern threats. Contrary to our predictions, however, acetaminophen altered affective responses to ancestral and modern threats in a highly similar manner. We conclude that acetaminophen does not blunt overall affective processing, and call for further evolutionary-based research examining the various psychoactive effects of this commonly consumed over-the-counter painkiller.

The Effect of Impression Formation on Rejection in the Ultimatum Game

Previous studies have attempted to elucidate people’s motives for rejecting unfair offers in the ultimatum game. One approach assumes that people reject unfair offers to punish ill intentions behind the offers, motivated by retribution and/or deterrence. To disentangle these two motives and investigate when each motive drives rejection, we focused on people’s tendency to form moral impressions rapidly. We hypothesized that the deterrence motive would drive rejection when the negative impression of those who have made unfair offers is uncertain, while the retribution motive would drive rejection when the impression is certain. The result of an online experiment (N = 199) of a repeated mini-ultimatum game did not support our hypothesis; the certainty of the negative impression did not have significant effects on rejection of unfairness. We discuss the implications of this result, incorporating the results of exploratory analyses regarding self-reported motives.

Checking Boxes for Making an Apology: Testing the Valuable Relationships Hypothesis by a New Method

A reconciliation signal may have evolved because it can reduce the uncertainty of defection, which might be caused by an error in a repeated prisoner’s dilemma situation. Ohtsubo and Watanabe (2009) proposed the “costly apology model” and argued that transgressors should make apologies in a costly way to convey sincerity to victims. Ohtsubo and Yagi (2015) showed that people are more likely to make a costly apology to valuable partners than to less valuable ones. The cost of apology was measured by the strength of willingness to suffer some inconvenience (e.g., cancellation of an important meeting) for it. Such a method of measuring costs is, however, dependent on culture, context, and the participants’ personal situations, and can only measure costs indirectly. We attempted to replicate the results of Ohtsubo and Yagi (2015) by using the checkbox method as a measurement of cost of apology. Among the factors expected to affect the number of checkboxes checked, the primary factor was the instrumentality of the friend, which replicated the results of Ohtsubo and Yagi (2015). Because the participants paid real costs of effort and time for fictitious mistakes, the costly apology might be triggered quickly and intuitively by a heuristic.

The Relationship Between Emotion Recognition from Facial Expression and Self-Construal

Previous studies have identified cultural differences in the patterns of emotion recognition, with Eastern cultures emphasizing emotional expression through the eyes and Western cultures emphasizing the facial expression around the mouth. The influence of self-construal has been considered a factor of these cultural differences, but no direct examination has been conducted to clarify how cultural factors are related to self-construal. To examine this relationship and exclude cultural influences other than relational self-construal, this study involved three experiments regarding self-construal and emotion recognition in Japanese subjects. The results showed that the participants perceive sadness more strongly through the eye region when they have a high degree of interdependence, and they perceive happiness more strongly through the mouth region when they have a high degree of independence. The results partially confirm the results of previous research and highlight that self-construal plays a role in interpreting facial cues; these findings suggest that more detailed studies and research focusing on other cultures should be conducted to clarify (1) cultural influence on self-construal and (2) cultural influence on emotion recognition.

The Relationship Between Emotion Recognition from Facial Expression and Self-Construal

Previous studies have identified cultural differences in the patterns of emotion recognition, with Eastern cultures emphasizing emotional expression through the eyes and Western cultures emphasizing the facial expression around the mouth. The influence of self-construal has been considered a factor of these cultural differences, but no direct examination has been conducted to clarify how cultural factors are related to self-construal. To examine this relationship and exclude cultural influences other than relational self-construal, this study involved three experiments regarding self-construal and emotion recognition in Japanese subjects. The results showed that the participants perceive sadness more strongly through the eye region when they have a high degree of interdependence, and they perceive happiness more strongly through the mouth region when they have a high degree of independence. The results partially confirm the results of previous research and highlight that self-construal plays a role in interpreting facial cues; these findings suggest that more detailed studies and research focusing on other cultures should be conducted to clarify (1) cultural influence on self-construal and (2) cultural influence on emotion recognition.