[Effects of relational efficacy on two attachment functions: evidence from romantic relationships and same-sex friendships].

This study investigated how relational efficacy affects functions of safe haven and secure base in romantic relationships and same-sex friendships. Relational efficacy, which is a shared or intersubjective efficacy of relationship partners, refers to a pair's belief that they can mutually coordinate and integrate their resources to prevent and resolve any problems. Participants were 97 dating heterosexual couples and 119 same-sex friendships. Multilevel structural equation modeling suggested that relational efficacy promotes the safe haven function and the secure base function in romantic relationships and same-sex friendships, controlled for sex, relationship longevity, irreplaceability, attachment anxiety, and attachment avoidance. Additionally, the effects of relational efficacy on the safe haven function and the secure base function in romantic relationships are stronger than in same-sex friendships. These results are discussed in terms of the association between intersubjective processes in close relationships and individuals' hedonic/eudaimonic well-being.