Abstract
Why do men and women compete? And what makes them compete more or less? An answer to the first question follows directly from Darwin. If Homo sapiens, like other species, is a product of natural selection, then we should have evolved to compete in order to reproduce. An answer to the second question follows from more recent versions of Darwinism. People, like other organisms, are likely to compete socially - to form dominance hierarchies - to the extent that it is costly for subordinates to flee ecologically. This paper first reviews evidence that winners at political competition have consistently won at reproductive competition. Next, it documents the slow shift toward declining political competition - toward democracy, and toward declining reproductive competition - toward monogamy, in the course of Western history. Last, it offers a model of what might account for that change.