Humans have evolved ways to non-consciously detect infidelity, as well as methods to both detect and deal with a love partner’s betrayal Jealousy is one such adaptation. Both infidelity and the jealousy that arises in anticipation of, or along with it are problems that bring couples to therapy. Categorizing jealousy as a sign of emotional dysfunction versus viewing it as a normal response turns out to be difficult for the clinician. This is partially a result of the evolution of infidelity to be concealed from the betrayed partner, Thus, the secrecy of infidelity makes the legitimately jealous partner seem inappropriate.
One solution is to view it as a signal detection problem. Because failing to detect a cheating partner has been more costly in evolutionary value than the social costs of falsely suspecting a partner of cheating. Thus, evolutionary natural selection has created a cognitive bias to overestimate a partner’s straying. Moreover, adaptations for jealousy become activated by predictors of infidelity, such as mate value discrepancies, when no actual infidelities have occurred. Cognitive-behavior therapy (CBT) offers several ways to deal with these complexities. One way is to highlight potential mismatches, distinguishing between jealous emotions that were functional in ancestral environments but are less so in modern environments. A second is to distinguish between the goal of personal well-being and reproductive outcomes. Understanding the evolutionary logic of jealousy, in short, provides people with procedural methods for cognitively reframing jealousy and infidelity.