Effects of affiliation arousal (hope of closeness) and affiliation stress (fear of rejection) on progesterone and cortisol.

Our prior research has suggested a connection between progesterone (PROG) and implicit affiliation motivation, the non-conscious drive for positive social contact. In particular, experimental arousal of affiliation motivation led to relative PROG increase in women and men [Schultheiss, O.C., Wirth, M.M., Stanton, S.J., 2004. Effects of affiliation and power motivation arousal on salivary progesterone and testosterone. Horm. Behav. 46(5), 592-599]. The present study aimed to (1) replicate this effect, (2) simultaneously assess cortisol (CORT) levels in this paradigm in order to rule out non-specific adrenal effects induced by affiliation arousal, and (3) examine effects on PROG and CORT of approach (hope for closeness, HOC) versus avoidance (fear of rejection, FOR) affiliation arousal. These motivational states were experimentally aroused in participants using film segments containing approach- or avoidance-oriented affiliation-related themes; a neutral film segment was used as a control condition. The film segments affected participants' implicit affiliation motivation and self-reported mood, demonstrating effectiveness of the manipulation. In the FOR condition, participants' CORT and PROG were increased post-film, consistent with the idea that fear of rejection is stressful. We did not replicate our prior finding of PROG increase following the HOC manipulation. However, relationships between PROG and implicit affiliation motivation were apparent across conditions. In particular, PROG co-varied positively with affiliation motivation, and baseline affiliation motivation positively predicted PROG increase in the FOR condition. As prior research implicates PROG in down-regulation of stress, we speculate that PROG release during stress may encourage affiliation for stress reduction purposes.