Psychological Topics (Jul 2015)
Obsessive Compulsive Personality Disorder as an Adaptive Anachronism: The Operation of Phylogenetic Inertia Upon Obsessive Populations in Western Modernity
Abstract
Consistent with its classification by the American Psychiatric Association as one of ten personality disorders, nearly all etiologies assume Obsessive Compulsive Personality Disorder to be an environmentally instilled syndrome. However, a recent evolutionary etiology, better accounting for prevalence rates and heritability estimates, ecologically explains obsessive psychology as an adaptation to northern climates with express seasonality, low population density, and low social complexity. While this evolutionary etiology justifiably eschews assumptions of pathology, it does not explain why those assumptions were so long made. To this end, the concept of phylogenetic inertia, the decrease in fitness arising from incongruity between past and present selective pressures, is applied. The present paper considers how an evolved strategy could be mistaken for a detrimental disorder by examining the misalignment between evolved obsessive psychology and modernity's demands for flexible attention, communion and collaboration, openness and complexity. As discussed, however, empirical studies are divided, such that only some show evidence of dysfunction; moreover, any evidence of dysfunction is relativistic in that it does not impair survival or decrease reproduction. While suggestions for future research are made, from the weight of present evidence it appears that Obsessive Compulsive Personality Disorder, evolved in prehistory, remains adaptive in modernity and so phylogenetic inertia can only be invoked as a metaphorical heuristic.
