Gaze and speech behavior in parent–child interactions: The role of conflict and cooperation

A primary mode of human social behavior is face-to-face interaction. In this study, we investigated the characteristics of gaze and its relation to speech behavior during video-mediated face-to-face interactions between parents and their preadolescent children. 81 parent–child dyads engaged in conversations about cooperative and conflictive family topics. We used a dual-eye tracking setup that is capable of concurrently recording eye movements, frontal video, and audio from two conversational partners. Our results show that children spoke more in the cooperation-scenario whereas parents spoke more in the conflict-scenario. Parents gazed slightly more at the eyes of their children in the conflict-scenario compared to the cooperation-scenario. Both parents and children looked more at the other's mouth region while listening compared to while speaking. Results are discussed in terms of the role that parents and children take during cooperative and conflictive interactions and how gaze behavior may support and coordinate such interactions.

The evolution of altruism through war is highly sensitive to population structure and to civilian and fighter mortality

The importance of warfare in the evolution of human social behavior remains highly debated. One hypothesis is that intense warfare between groups favored altruism within groups, a hypothesis given some support by computational modeling and, in particular, the work of Choi and Bowles [J.-K. Choi, S. Bowles, Science 318, 636–640 (2007)]. The results of computational models are, however, sensitive to chosen parameter values and a deeper assessment of the plausibility of the parochial altruism hypothesis requires exploring this model in more detail. Here, I use a recently developed method to reexamine Choi and Bowles’ model under a much broader range of conditions to those used in the original paper. Although the evolution of altruism is robust to perturbations in most of the default parameters, it is highly sensitive to group size and migration and to the lethality of war. The results show that the degree of genetic differentiation between groups (FST) produced by Choi and Bowles’ original model is much greater than empirical estimates of FST between hunter-gatherer groups. When FST in the model is close to empirically observed values, altruism does not evolve. These results cast doubt on the importance of war in the evolution of human sociality.

Psychological selfishness

Selfishness is central to many theories of human morality, yet its psychological nature remains largely overlooked. Psychologists often rely on classical conceptions of selfishness from economics (i.e., rational self-interest) and philosophy (i.e. psychological egoism), but such characterizations offer limited insight into the richer, motivated nature of selfishness. To address this gap, we propose a novel framework in which selfishness is recast as a psychological construction. From this view, selfishness is perceived in ourselves and others when we detect a situation-specific desire to benefit oneself that disregards others’ desires and prevailing social expectations for the situation. We argue that detecting and deterring such psychological selfishness in both oneself and others is crucial in social life—facilitating the maintenance of social cohesion and close relationships. In addition, we show how utilizing this psychological framework offers a richer understanding of the nature of human social behavior. Delineating a psychological construct of selfishness can promote coherence in interdisciplinary research on selfishness, and provide insights for interventions to prevent or remediate negative effects of selfishness.

Correction to: Epigenetic tuning of brain signal entropy in emergent human social behavior

An amendment to this paper has been published and can be accessed via the original article.

Bargaining under social distancing requirements: Effects of face masks on socio-economic decision-making in the COVID-19 pandemic

Face masks play a pivotal role in the control and prevention of respiratory diseases, such as the novel coronavirus (COVID-19). Despite their widespread use, it is not known how face masks affect human social interaction. In this behavioral economics study (N = 475), we examined how mask-wearing modulates individuals’ likelihood of acceptance of unfair monetary offers in an iterated social exchange. Overall, participants accepted more offers, including more unfair offers, from mask-wearing opponents than from opponents without a mask. This effect was enhanced when participants ascribed more altruistic motives to their interaction partner. Importantly, this pattern of results was only present for surgical face masks, but not when a non-medical cloth face covering was used. This is the first study to uncover a new phenomenon, the face-mask effect, in which face masks can alter human social behavior.