Evolutionary psychology attempts to explain human motivations and behavior as being the consequence of evolution, and as pursuing personal survival and benefit in a competition with other people, and most importantly, as pursuing successful reproduction. Without applying evolutionary theory there is no scientific way to say whether a behavior is adaptive (serves a purpose) or not (see Intentional Design.)

Evolutionary psychology (and the similar Sociobiology) have generated a great deal of controversy (see Just-So Stories.) Clearly humans are the product of evolution, and clearly our ancestors were rather successful at reproducing. The question is how much this helps us in explaining human behavior, and what does it mean that human behavior can be explained in this way? To many it seems nonsensical to propose that having lots of grandchildren is the intention underlying all human behavior because:

• Especially in the modern world, most of our daily activities don't advance our supposed reproductive goal in any obvious way (reading People magazine), and in many cases clearly reduce the prospects for our continued survival (binge drinking, running for president.)
• When you ask people what their intention is they will hardly ever mention reproductive success. If you press someone for the ultimate top-level goal it will usually be either emotional (because I love her), moral (it was the right thing to do) or spiritual (it gives meaning to my life.)

The evolutionary psychologists reply that:

• Many apparently unproductive activities either do advance our reproductive success (in ways that are either subtle or politically incorrect), or were adaptive up until recently, or can be regarded as an incidental side-effect of important adaptive behaviors, and (most infuriatingly)
• That we behave as though reproductive success were our intention even though this is not the intention that we are conscious of.

Even within evolutionary psychology there is considerable dispute about whether behaviors such as music and religion are adaptive or not, and to what degree they are hard-wired. This distinction is in fact somewhat ill-founded, because as Daniel Dennett points out in Darwin's Dangerous Idea, all adaptation is exaptation. This means every feature or behavior of an organism must have its origin in a feature that was purely accidental, or served a different purpose. While it is clearly true that many of an organism's structures and behavior serve purposes, there are also many traits with no clear purpose. It may serve no purpose at all, or might have multiple minor benefits.

We feel that evolutionary psychology has generated some rather successful explanations of some human behavior, especially Sex Differences, but it is at risk of incorrect explanations of the status quo via Just-So Stories, and these can be misinterpreted as justifications for the status quo. Also, because of Level Confusion and a lack of appreciation for Emergence, these explanations are seen as demeaning and denying the reality of fundamental human motivations and feelings. This conflict underlies the Smarty-Pants Critique critique of the evolutionary psychology viewpoint.

A major area of dispute, and something that does appear susceptible to scientific examination, is the degree to which human behavior is genetically determined, vs. established by culture, that is the Nature Versus Nurture dispute. Advocates of evolutionary psychology tend strongly toward genetic determinism, whereas opponents tend to believe that humans are more of a blank slate.

See also Reprogramming the Mind.