The Manhattan effect: when relationship commitment fails to promote support for partners' interests.

Research on close relationships has frequently contrasted one's own interests with the interests of the partner or the relationship and has tended to view the partner's and the relationship's interests as inherently aligned. The present article demonstrated that relationship commitment typically causes people to support their partner's personal interests but that this effect gets weaker to the extent that those interests misalign or even threaten the relationship. Studies 1a and 1b showed that (a) despite their strong correlation, partner-oriented and relationship-oriented concerns in goal-directed behaviors are separable and (b) relationship commitment strengthens only the link between relationship-oriented motivation and the goal pursuit (not the link between partner-oriented motivation and the goal pursuit). The remaining 7 studies zero in on circumstances in which the partner's and the relationship's interests are in conflict, demonstrating that (c) relationship commitment reliably increases the tendency to support the partner's personal interests when those interests do not pose a strong threat to the relationship but that (d) this effect becomes weaker-and even reverses direction-as the relationship threat posed by the partner's interests becomes stronger. The reduction or reversal of the positive link between relationship commitment and propartner behaviors in such situations is termed the Manhattan effect. These findings suggest that the partner-versus-relationship conflicts provide fertile ground for novel theorizing and empirical investigations and that relationship commitment appears to be less of a partner-promoting construct than relationship science has suggested; instead, its role appears to be focused on promoting the interests of the relationship.