A mathematical analysis of the evolution of human mate choice traits: Implications for evolutionary psychologists

Abstract

Abstract. Sexually reproducing organisms often rely on various traits to judge the attractiveness of potential mates. Many mate choice preferences and traits have evolved through selection by those organisms' ancestors, with traits having been either costly (detrimental to survival) or noncostly in the environment of their evolutionary adaptation. A general mathematical analysis of the evolution of traits used in mate choice is presented. The analysis builds on a combination of Price's covariance equation and Wright's method of path analysis, and includes a set of Monte Carlo simulations. The usefulness of the mathematical analysis is demonstrated through the development of a small but important set of hypotheses and implications for the human species: (1) costly traits used in mate choice by humans should be generally less common and more attractive to the other sex than non-costly traits; (2) costly traits should be disproportionately less common in human females than in males; and (3) some harmful human mental disorders, such as schizophrenia, may have co-evolved as costs of attractive mental traits. It is also shown that similar analyses can be easily employed by evolutionary psychologists to theorize about the evolution of complex mate choice traits, and to test the resulting theories with modern humans through the method of path analysis.

A six-stage framework for evolutionary IS research using path models

“…However, here this does not prevent the trait measured by "a" from evolving, because the total effect of "a" on "w", via "x" and "y", is positive. Here the trait measured by "y" is an example of "costly" trait, or evolutionary handicap (Kock, 2011;Zahavi & Zahavi, 1997).…”

“…As such, this trait would increase mating success in males who possessed it in our ancestral past, even as the trait decreased those individuals' survival success. If the net effect on reproductive success were positive, as illustrated in the model above, the trait would evolve as a costly trait (Kock, 2011).…”

“…While arguably our illustration (presented later) does not explicitly take advantage of this modeling capability in connection with sexual selection, it is still a useful element of the theory development framework we lay out. With this precise understanding, one can explicitly model the evolution of costly traits, whereby traits that influence survival success in a negative way evolve because of the traits' overall impact on reproductive success (Kock, 2011;Zahavi & Zahavi, 1997).…”

“…Traits can increase or decrease the survival and/or mating success of the individuals that possess the traits. If a trait decreases survival and/or mating success it will often disappear from the population, although there are instances in which such a trait will spread throughout the population as a costly trait (Kock, 2011).…”

An evolutionary hypothesis to explain the role of deconditioning in low back pain prevalence in humans

“…From this it could be deduced that LBP must have had little impact upon reproductive success in order for it to still remain as a highly prevalent condition. In fact many evolutionarily derived traits have both positive and negative effects upon reproductive success and are termed as 'costly' [182]. What is important is the net effect upon reproductive success.…”