Pupillometric Response to Implicit Social Exclusion

Previous research suggests that people are highly sensitive to rejection, and may even display physiological reactions, such as increased pupil dilation, when they are explicitly rejected by others compared to when they are accepted (Silk et al., 2012). To our knowledge, no research to date has investigated pupil dilation in response to implicit social exclusion. To address this gap, we obtained pupillometric values using a Cyberball paradigm, in which 11 participants were either included or indirectly excluded while playing an online ball game. Participants were told before each game that they would be playing with either human players (i.e., other participants in the study) or pre-programmed computer players; in reality, all players were computerized. We found that difference in maximum pupil dilation was significantly larger for exclusion compared to inclusion games after playing with human players, t(10)=2.947, p=.015. However, difference in maximum pupil dilation did not differ between exclusion and inclusion games after playing with computerized players, t(9)=-.087, p=.933. Consistent with extant literature, participants reported lower self-ratings of mood, control, belonging, and self-esteem after exclusion games compared to inclusion games on both human and computerized trials. These findings suggest that pupillometry is a sensitive and useful measure for investigating responses to social exclusion