Genetic moderation of sensitivity to positive and negative affect in marriage

Hypothesizing that genetic factors partially govern sensitivity to interpersonal cues, we examined whether a polymorphism (5-HTTLPR) in the serotonin transporter gene would moderate spouses' sensitivity to positive and negative partner affect. Before and after marital discussions, participants from 76 couples (total n = 150) reported their affective states. Spouses carrying the short allele of the 5-HTTLPR were more responsive to their partner's preinteraction positive affect and anxiety/nervousness, compared with spouses with two long alleles. These data support the contention that the serotonin system influences affective responses to social stimuli. In contrast to the view that the 5-HTTLPR primarily affects response to adverse experiences, these results suggest that this polymorphism moderates sensitivity to positive as well as negative affect.