Despite frequent sanctions and potentially serious consequences, extra-dyadic involvements are a relatively common phenomenon. Previously, potential links among extradyadic involvements and personal or interpersonal characteristics were extensively explored.
However, the developmental aspects of extra-dyadic relationships have been rather overlooked to date. Here, we focus on the association between selfreported extra-dyadic tendencies and behavior, and previous experience with extra-dyadic sex in prior romantic relationships and in the primary family.We asked both members of 86 longterm cohabiting couples to complete several inventories assessing various aspects of the relationship satisfaction, sociosexuality and extra-dyadic intentions and behavior.
As in previous studies,wefoundalowerlevelofoverallDyadicAdjustmentand in the subscales Affectional Expression andDyadic Consensus, inparticular,amongwomenbutnotmenwhoreportedextra-pair sex. Neither experience with own nor partners'' infidelity in previousrelationshipswaslinkedtoreportedextra-pair sexin the current relationship.
However, men who reported their fathers but not mothers being unfaithful were also significantly more often unfaithful and showed a higher level of extra-dyadic intentions. There was no association between parental infidelity and extra-pair sex or extra-dyadic intentions in women.
Our results suggest that experience of infidelity within the primary family has an impact on subsequent behavior. However, this is thecaseonlyinmen.Women''sextra-dyadicactivities seemtobe affected instead by the quality of the current relationship.
Future research is needed to test the influence of ontogenetic and hereditary factors on the development of infidelity tendencies.