• minds consist of discrete, problem-solving modules
• natural selection determines the kinds of problems that a particular brain will be adept at recognizing and solving
• complex adaptations evolve very slowly
• the environment of human behavioral evolution most likely resembled a small-scale, foraging society, rather than the stratified societies and dense, urban cities which characterize the present day
• understanding human psychology requires one to examine the kinds of problems frequently encountered over the larger part of human behavioral evolution

The basis of inference for evolutionary psychologists is the environment of evolutionary adaptations (EEA), or the past situations which human cognitive abilities were designed to address. One problem with this notion is that little is known about the genetic basis of psychological concepts. Whether or not certain characters evolved very early in evolution or much later is highly variable, and often unknown, which leads to uncertainty concerning the particular environment of adaptations. After all, human evolution proceeded through a great many ecological and cultural changes over the past 2 million years. Further, even if psychological variables were simultaneously fixed at a given point in human history, determination of the characteristics of the environment remains a highly speculative venture. Does a model of hunter-gatherer society from the present adequately represent the past social and ecological environment? In what repects might it have differed?

These theoretical problems are difficult to explain away by practitioners of evolutionary psychology. Yet, the field itself has led to some very provocative insights. Biases in human cognitive processes are evident in problem solving tasks which involve social exchange (i.e., those problems in which there is a potential gain or loss in social status). Also, memory appears especially sharp in keeping track of debtors, while "accidentally" forgetting debts to others (or downplaying them). Human beings appear to be especially proficient at playing the game of social manipulation and status acquisition - and are, in that respect, much like our non-human primate relatives.

Evolution and Human Culture

copyright 2000, Ann M. Kakaliouras

Human culture has long been recognized as a highly specialized, extrasomatic means of adapting to a rapidly changing environment. However, humans are not unique in having a means of adaptation which in transferred from generation to generation through non-biological means. Information transmission may occur via the mechanisms of social facilitation, observation, and imitation. Indeed, cultural variations in diet and behavior have been observed among regional populations of the common chimpanzee, Pan troglodytes, while socially transmitted behaviors were documented among Japanese macaques (e.g., potato-washing, wet-sieving). When examining human adaptive behaviors in light of the primatological literature, it becomes apparent that the differences between human and non-human primate behaviors are differences in degree, but not differences in kind.