Pilkington, C. J., Nezlek, J. B., & Bilbro, K. G. (2000). Day-to-day social interactions with same- and opposite-sex friends and romantic partners.

Ninety undergraduate participants, all with active same- and opposite-sex friendships and an active romantic relationship, described all their social interactions for a week. People had more contact with romantic partners than with either same- or opposite-sex friends, and interactions with romantic partners were more intimate and more enjoyable than interactions with same- or opposite-sex friends. There were no differences, however, among interactions with the three relational partners in the breadth and depth of disclosure, in how responsive others were to participants' needs, and in how influential participants felt. Moreover, there were few sex differences in these behaviors. Surprisingly, half of participants did not interact with their opposite-sex friends during the study. There were no meaningful relationships between reports of interactions with relational partners and descriptions of these relationships provided by the Relationships Closeness Inventory and measures of trust.