Assortative mating and the evolution of desirability covariation

Mate choice lies close to differential reproduction, the engine of evolution. Patterns of mate choice consequently have power to direct the course of evolution. Here we provide evidence suggesting one pattern of human mate choice—the tendency for mates to be similar in overall desirability—caused the evolution of a structure of correlations that we call the d factor. We use agent-based models to demonstrate that assortative mating causes the evolution of a positive manifold of desirability, d, such that an individual who is desirable as a mate along any one dimension tends to be desirable across all other dimensions. Further, we use a large cross-cultural sample with n = 14,478 from 45 countries around the world to show that this d-factor emerges in human samples, is a cross-cultural universal, and is patterned in a way consistent with an evolutionary history of assortative mating. Our results suggest that assortative mating can explain the evolution of a broad structure of human trait covariation.