Correlates of Extra-Dyadic Sex in Czech Heterosexual Couples: Does Sexual Behavior of Parents Matters?

Despite frequent sanctions and potentially serious consequences, extra-dyadic involvements are a relatively common phenomenon.
Previously, potential links among extra-dyadic 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 self-reported 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 long-term cohabiting couples to complete
several inventories assessing various aspects of the relationship satisfaction, sociosexuality and extra-dyadic intentions
and behavior. As in previous studies, we found a lower level of overall Dyadic Adjustment and in the subscales Affectional
Expression and Dyadic Consensus, in particular, among women but not men who reported extra-pair sex. Neither experience with
own nor partners’ infidelity in previous relationships was linked to reported extra-pair sex in 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 the case only in men. Women’s extra-dyadic activities seem to be 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.