Evolutionary psychologists should pay more attention to Tinbergen's other two questions.

Tinbergen (1963) classified 4 conceptual domains necessary for understanding behavior: evolutionary function, phylogeny, mechanism, and development. Evolutionary psychology has primarily focused on the 1st 2. I propose that evolutionary psychology will advance more solidly and steadily by increasing attention to putative adaptations’ mechanism and development. To illustrate, I mainly focus on the sex difference in casual sex interest (sociosexuality) as discussed by Symons (1979). (PsycInfo Database Record (c) 2020 APA, all rights reserved) Public Significance Statement—Tinbergen famously posed four questions that for ethology, which also apply to evolutionary psychology. Evolutionary psychologists have paid too little attention to two of Tinbergen's questions: how do putative adaptations work, and how do they develop? I focus on opportunities to study hormonal influences on the sex difference in casual sex interest. (PsycInfo Database Record (c) 2020 APA, all rights reserved)