Differential activation of the ventromedial prefrontal cortex between male and female givers of social reputation

Communicating the cost of your altruism makes you cool—competitive altruism and sexual selection in a real-life charity situation

Abstract

Maintaining a good reputation is crucial for humans. Altruism, e.g. charity, may serve as a costly signal that enhances reputation based on the real or communicated cost. Fundraising via charity running triggers competitive altruism when potential donors donate in reaction to the reputation increase of the fundraiser. Using real-life data of marathonists and half-marathonists (388 runners) and their 9281 donors, the present research focuses on how the communicated cost and goal of a charity run affected the potential donors. We analysed the introductory texts of the runners presented online according to the cost and the social benefit of the fundraising communicated by them. We have shown that emphasizing more the subjective cost of running and the social benefit of the goal, or writing a longer text, attracted more donors and, even though the average amount of donation per donor did not increase, still lead to a greater amount of donations collected overall by the fundraiser. It was also shown that a higher communicated subjective cost resulted in a higher ratio of opposite-sex donors, both in the case of male and female runners, suggesting that the communication of the cost of an altruistic act might be the object of sexual selection.

Significance statement

A good reputation is crucial for humans, as a reputable person enjoys several benefits. One way to maintain a good reputation is to be altruistic, e.g. doing charity. A seemingly high cost and a socially accepted goal may result in a higher reputation. Using data from a charity running community we demonstrate that fundraisers who emphasize their subjective cost (how difficult to run), and emphasize the good goal of the charity, attract more donors, and even though the average amount of each donation does not increase, a higher number of donors results in a greater amount of donations collected overall. Talking about the difficulties of the charity run results in a higher ratio of opposite-sex donors. Our results may be helpful to plan more successful charity events or to make a human community more altruistic and cooperative in general.

The Role of the Ventromedial Prefrontal Cortex in Preferential Decisions for Own- and Other-Age Faces

Own-age bias is a well-known bias reflecting the effects of age, and its role has been demonstrated, particularly, in face recognition. However, it remains unclear whether an own-age bias exists in facial impression formation. In the present study, we used three datasets from two published and one unpublished functional magnetic resonance imaging (fMRI) study that employed the same pleasantness rating task with fMRI scanning and preferential choice task after the fMRI to investigate whether healthy young and older participants showed own-age effects in face preference. Specifically, we employed a drift-diffusion model to elaborate the existence of own-age bias in the processes of preferential choice. The behavioral results showed higher rating scores and higher drift rate for young faces than for older faces, regardless of the ages of participants. We identified a young-age effect, but not an own-age effect. Neuroimaging results from aggregation analysis of the three datasets suggest a possibility that the ventromedial prefrontal cortex (vmPFC) was associated with evidence accumulation of own-age faces; however, no clear evidence was provided. Importantly, we found no age-related decline in the responsiveness of the vmPFC to subjective pleasantness of faces, and both young and older participants showed a contribution of the vmPFC to the parametric representation of the subjective value of face and functional coupling between the vmPFC and ventral visual area, which reflects face preference. These results suggest that the preferential choice of face is less susceptible to the own-age bias across the lifespan of individuals.

The role of the ventromedial prefrontal cortex in automatic formation of impression and reflected impression

Previous neuroimaging studies demonstrated that ventromedial prefrontal cortex (vmPFC) activity reflects how much an individual positively views each person (impression). Here, we investigated whether the degree to which individuals think others positively view them (reflected impression) is similarly tracked by activity in the vmPFC by using fMRI and speed-dating events. We also examined whether activity of the vmPFC in response to the faces of others would predict the impression formed through direct interactions with them. The task consisted of three sessions: pre-speed-dating fMRI, speed-dating events, and post-speed-dating fMRI (not reported here). During the pre-speed-dating fMRI, each participant passively viewed the faces of others whom they would meet in the subsequent speed-dating events. After the fMRI, they rated the impression and reflected impression of each face. During the speed-dating events, the participants had 3-min conversations with partners whose faces were presented during the fMRI task, and they were asked to choose the partners whom they preferred at the end of the events. The results revealed that the value of both the impression and reflected impression were automatically represented in the vmPFC. However, the impression fully mediated the link between the reflected impression and vmPFC activity. These results highlight a close link between reflected appraisal and impression formation and provide important insights into neural and psychological models of how the reflected impression is formed in the human brain.