Paternal investment and economic inequality predict cross-cultural variation in male choice

Over the last decades, behavioral ecologists have found a few species with conspicuous female traits not expected under a Darwinian sexual selection regime. Cosmetics, which are predominantly used by human females, can be broadly understood as a cultural manipulation of conspicuous traits. Both can be explained using a small twist on classical Darwinian sexual selection. The key variable is the cost of reproduction. The sex that incurs higher reproductive costs will be choosier and more discriminating. Traditionally, female reproductive costs of egg production, gestation, and lactation have given weight to female choices. However, when males spend more or as much on reproductive costs as females, conspicuous female traits and male choices occur. Multivariate regression analysis was performed using the size of the cosmetics industry in each country (source: Euromonitor, N = 55) as the outcome variable as a proxy for male choice. Two male resource variables, paternal investment (female to male ratio of unpaid domestic, child care hours, source: OECD, N = 32) and economic inequality (income inequality, source: CIA, N = 55/ social mobility index, source: world economic forum, N = 49) stand out as predictors of cross-cultural variation in cosmetics use. Human mating research that examines mutual mate choice and its cultural manipulation could serve as a model for other animals with mutual ornamentation and mimicry.