The influence of passionate love on self-other discrimination during joint action.

Prior research on romantic relationships suggests that being in love involves a blurring of self-other cognitive boundaries. However, this research has focused so far on conceptual self-representation, related to the individual's traits or interests. The present study tested the hypothesis that passionate love involves a reduced discrimination between the self and the romantic partner at a bodily level, as indexed by an increased Joint Simon effect (JSE), and we further examined whether this self-other discrimination correlated with the passion felt for the partner. As predicted, we found an increased JSE when participants performed the Joint Simon Task with their romantic partner compared with a friend of the opposite sex. Providing support for the self-expansion model of love (Aron and Aron in Pers Relatsh 3(1):45-58, 1996), this result indicates that romantic relationships blur the boundaries between the self and the romantic partner at a bodily level. Furthermore, the strength of romantic feelings was positively correlated with the magnitude of the JSE when sharing the task with the romantic partner.