Can attitude similarity shape social inhibition of return?

We examined whether the perceived similarity between two individuals can shape social attention shifts during a joint-action task. Initially, a confederate was described to a naïve participant through a personality profile in order to manipulate the degree of attitude similarity between them, and they later performed a joint-action task involving alternated aiming movements towards peripheral targets. This task is known to elicit two forms of Inhibition of Return (IOR), namely longer latencies when responding to a target previously reached by either oneself (individual IOR) or by the partner (social IOR) as compared to a previously-unreached target. Here, both IOR effects emerged but–unlike previous studies–social IOR was greater than individual IOR. Interestingly, such magnified social IOR occurred regardless of the degree of attitude similarity between participants. This seems to suggest that social knowledge about others can lead to a generalized impact on social attention during real interactions with them.