Abstract
Predicting others’ actions is crucial to successful social interaction. Previous research on joint action, based on a reaction-time paradigm called the Joint Simon Task, suggests that successful joint action stems from the simultaneous representation of the self with the other. Performance on this task provides a read-out of the degree of intrusion from a partner that participants experience from acting jointly compared to acting alone, which in turn is a measure of the degree to which participants mentally represent their co-actors during the task. To investigate the role of perceived group membership in this type of joint action and its influence on the representation of others, we first subjected participants to a minimal group paradigm while manipulating differences in social competition. We then asked participants to do the Joint Simon Task in pairs with an in-group or out-group member. Only participants who acted with an “in-group” partner on the joint task showed altered reaction times compared to when acting alone, presumably a change caused by the simultaneous and automatic representation of their in-group partner. In contrast, participants who acted with an out-group partner were unaffected in their reactions when doing the joint task, showing no evidence of representation of their out-group partner. This effect was present in both the high-competition and low-competition conditions, indicating that the differential effects of group membership on representation during joint action were driven by perceived group membership and independent of the effects of social competition. We concluded that participants failed to represent out-group members as socially relevant agents not based on any personality or situational characteristics, but in reaction only to their status as “other”. In this way group membership appears to affect cognition on a very immediate and subconscious level.
Highlights
Group membership has well-documented and striking effects on human social behaviour
In this study we investigated whether people represented others during joint action as a function of their group membership
Using the Joint Simon Task [33] we replicated the well-established finding of a Social Simon Effect, in that participants doing the individual half of the task experienced no interference from the irrelevant spatial dimension, but they were significantly affected if asked to carry out the same task jointly with a partner
Summary
Group membership has well-documented and striking effects on human social behaviour. From the quotidian to the more rare, the range of effects of group membership on behaviour is vast. There are a number of ways of explaining this inconsistency It could be argued based on the results of the first study that the Social Simon effect is not a function of group membership per se (that is, whether the other is in-group or out-group) but rather of the specific norms, values, and histories associated with these racial groups. We might expect overall differences in performance between these two competition conditions because of the different levels of motivation they induce, the important point is that within each we would expect the motivational dimension to be constant across interactions with in-group vs out-group members This allowed us to address the impact of group membership on co-representation without the motivational confound. We predicted that group membership should be the only factor to influence the Social Simon Effect, regardless of the level of social competition, our social competition manipulation may affect the overall reaction time
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