Prof. Masaki Yuki and JSPS Overseas Fellow Robert Thomson published a new paper in Personal Relationships

Kito, M., Yuki, M.,& Thomson, R.(2017). Relational mobility and close relationships: A socioecological approach to explain cross-cultural differences. Personal Relationships.

Abstract

This article reviews how behaviors and psychological tendencies in close relationships differ between cultures, and proposes a socioecological framework to understand those differences. Our review of the literature finds that paradoxically, people in individualistic cultures are more actively engaged in close relationships (e.g., higher levels of social support, self-disclosure, intimacy, and love) than those in collectivistic cultures. From an adaptationist perspective, we argue that one reason for these differences is higher levels of relational mobility in individualistic cultures. In societies with high relational mobility, where relationships are relatively more fragile, more active engagement in close relationships helps individuals to impress potential, and retain current, partners. We emphasize the importance of examining socioecologies to better understand close relationships.

PDF paper download here: http://onlinelibrary.wiley.com/doi/10.1111/pere.12174/abstract

Assoc. Prof. Masanori Takezawa and his colleagues published a new paper in Scientific Reports

Horita, Y., Takezawa, M., Inukai, K., Kita, T., & Masuda, N. (2017). Reinforcement learning accounts for moody conditional cooperation behavior: experimental results. Scientific Reports, 7, 39275. https://doi.org/10.1038/srep39275.

Abstract

In social dilemma games, human participants often show conditional cooperation (CC) behavior or its variant called moody conditional cooperation (MCC), with which they basically tend to cooperate when many other peers have previously cooperated. Recent computational studies showed that CC and MCC behavioral patterns could be explained by reinforcement learning. In the present study, we use a repeated multiplayer prisoner’s dilemma game and the repeated public goods game played by human participants to examine whether MCC is observed across different types of game and the possibility that reinforcement learning explains observed behavior. We observed MCC behavior in both games, but the MCC that we observed was different from that observed in the past experiments. In the present study, whether or not a focal participant cooperated previously affected the overall level of cooperation, instead of changing the tendency of cooperation in response to cooperation of other participants in the previous time step. We found that, across different conditions, reinforcement learning models were approximately as accurate as a MCC model in describing the experimental results. Consistent with the previous computational studies, the present results suggest that reinforcement learning may be a major proximate mechanism governing MCC behavior.

PDF paper download here: http://www.nature.com/articles/srep39275

Assoc. Prof. Ayaka Takimoto and others published a new paper in Neuroscience & Biobehavioral Reviews

Anderson, J. R., Bucher, B., Chijiiwa, H., Kuroshima, H., Takimoto, A., & Fujita, K.(2017).Third-party social evaluations of humans by monkeys and dogs. Neuroscience & Biobehavioral Reviews.

Abstract

Developmental psychologists are increasingly interested in young children’s evaluations of individuals based on third-party interactions. Studies have shown that infants react negatively to agents who display harmful intentions toward others, and to those who behave unfairly. We describe experimental studies of capuchin monkeys’ and pet dogs’ differential reactions to people who are helpful or unhelpful in third-party contexts, and monkeys’ responses to people who behave unfairly in exchanges of objects with a third party. We also present evidence that capuchin monkeys monitor the context of failures to help and violations of reciprocity, and that intentionality is one factor underlying their social evaluations of individuals whom they see interacting with others. We conclude by proposing some questions for studies of nonhuman species’ third party-based social evaluations.

PDF paper download here: http://www.sciencedirect.com/science/article/pii/S0149763416303578