The arrival of Evolutionary Psychology (EP) has upset many psychologists. Partly, this reflects resistance to what is perceived as genetic reductionism, partly worry about yet another step closer to the life sciences. Are the life sciences going to devour the social sciences? This essay starts out with a list of pitfalls for the beginning Darwinists that many EP followers are, warning against simplistic adptationist scenarios, and the fragmentation of the organism, the human brain (a module for every capacity), and the genome (a gene for this and a gene for that). Despite these criticisms, the author is generally sympathetic to the evolutionary approach, however, and feels that EP is inevitable. It may show growing pains, but psychology does need to move under the evolutionary umbrella, which is the only framework that can provide coherence to a fragmented discipline. The essay concludes with several illustrations of the usefulness of evolutionary theory to explain the social behavior of primates. Primatologists face many of the same dilemmas as followers of EP in that primate behavior seems almost endlessly variable. Examples of political strategy, peacemaking, and reciprocal exchange show the complexity, the profound similarity to human behavior, and the promise of the evolutionary framework.