Morbid jealousy from an evolutionary psychological perspective

Individuals diagnosed with morbid jealousy have hypersensitive jealousy mechanisms that cause them to have irrational thoughts about their partner's fidelity and to exhibit extreme behaviors. Using a newly constructed database of 398 cases of morbid jealousy reported in the literature from 1940 to 2002, we tested four evolutionarily informed hypotheses about normally functioning jealousy mechanisms and applied them to this novel population of individuals diagnosed with morbid jealousy. We hypothesized that a greater percentage of men than women diagnosed with morbid jealousy would be focused on a partner's sexual infidelity and on indicators of a rival's status and resources and that a greater percentage of women than men diagnosed with morbid jealousy would be focused on a partner's emotional infidelity and on indicators of a rival's youth and physical attractiveness. All four hypotheses were supported. The results suggest continuity between normal jealousy and morbid jealousy and highlight the heuristic value of using archival databases to test evolutionarily informed hypotheses.