Journal of Social and Personal Relationships, Ahead of Print.
This study investigated whether physical affection is causally associated with momentary intimacy and security by manipulating physical affection. We used a GPS-based smart-phone application as ecological momentary intervention that prompted participants to show physical affection to their partner when they were in the same location. We also investigated whether attachment style and attachment functioning moderated the effects of the manipulation. Thirty-nine couples were assigned to experimental (N = 20) and control (N = 19) groups for 2 weeks. Multilevel dyadic data analysis revealed significantly higher momentary intimacy in the experimental group, even when spontaneous physical affection was controlled; there was no significant change for momentary security. While attachment style did not moderate the effect of manipulation for either outcome, attachment functioning significantly moderated the effect on security. This is the first study to show evidence that physical affection, when instructed by a device, is causally linked to increased momentary intimacy in daily life.