Welcome to my first post. I specialize in evolutionary psychology (EP), which means I use evolutionary theory to try to understand human nature. More specifically, I'm interested in the cognitive mechanisms that allowed human ancestors to solve adaptive problems in the evolutionary past, and which currently enable the behavior of modern humans.

Notice that I use the word enable. One of my Ph.D. supervisors, Professor Donald Symons, once pointed out to me that many people have difficulty understanding that evolution enables behavior, because they're used to thinking of biology as something that constrains behavior. They see EP as a discipline that tries to impose limits on human freedom: if EP claims that people are adapted to behave in a certain way, then this implies that we're powerless to act in any other way, that we're prisoners of our own genes. People who assume this perspective would often like to see human behavior change in some way (for example, they might want people to act more altruistically), and they worry that EP's implied behavioral constraints will undermine this goal. It's ironic that they take this perspective, however, because getting people to change their behavior is actually much easier if you learn how evolved mental adaptations work than if you pretend that these adaptations don't exist. This idea of adaptation as limitation is counterproductive, and I'll say more about that in a moment, but first note that it's also just a very odd way to think about adaptation in general.

If you were trying to understand the design of some non-human species, you'd probably focus on how its adaptations enable it to solve specific problems that it encounters in its environment. In considering a nocturnal owl, for example, you might notice that its large wings, serrated wing feathers and light body allow it to fly slowly and silently in search of small  mammals, its exquisitely sensitive ears and eyes enable it to locate these prey in the dark, and its long talons permit it to capture and clench these prey. On the other hand, instead of focusing on how these physical devices solve problems for the owl, you could instead focus only on what the owl could not do as a result of its adaptations. You could emphasize, for example, that the owl's adaptations make it poorly designed for a life spent underwater or underground. You might focus on how the owl's genes constrain it to a life of flying through the forest at night in search of small rodents, and curtail its freedom to hunt insects by echolocation, or to dive deep beneath the ocean in pursuit of giant squid.

Even if it seems strange to understand nonhuman adaptations this way—to regard adaptations primarily as limitations, instead of as the mechanisms which make behavior possible—many people are inclined to think this way when interpreting EP's claims about human nature. For example, consider reactions to evolutionary views on human altruistic behavior.

EP research has long focused on altruism among people who are not close genetic kin, because this kind of altruism presents a puzzle: if evolution favors individuals who act in their own best genetic interests, then how could altruism evolve? Won't people who benefit the fitness (survival and reproduction) of other people, at the expense of their own fitness, be evolutionarily disadvantaged compared to selfish individuals who only helped themselves? Actually, no; as long as altruists direct their altruism primarily toward each other (that is, toward other altruists) instead of toward selfish individuals (cheaters), then the altruists can consume the benefits of altruism for themselves, while excluding the cheaters, and altruism can evolve. So altruism is most adaptive if it's conditional altruism (conditional upon beneficiaries being altruists as well). The general principle of conditional altruism goes under several names in EP, including reciprocal altruism, indirect reciprocity, partner choice and positive assortation. That's not to say that unconditional altruism--that is, altruism toward everyone, including non-altruists--can't evolve (indeed, even from the perspective of individual-level selection, there are ways in which it can evolve). However, such altruism will be rare, compared with conditional altruism.

EP researchers have identified several likely adaptations that appear to enable human altruism. These include mechanisms for detecting, excluding, and punishing cheaters, for selecting altruists as interaction partners, and for advertising one's own altruism. However, many people regard the EP perspective on altruism not as an effort to reveal the mechanisms that generate altruism, but rather as an attempt to emphasize constraints on human altruism. That is, they see this perspective as a cynical attempt to prove that because altruism is actually genetic selfishness, genuine altruism is illusory, and humans are condemned to lead lives of ignoble egocentrism.

Ultimately, the biggest disadvantage of equating adaptation with limitation is that it prevents you from using knowledge about adaptation to influence behavior. If we want to encourage altruism, for example, we won't get far by pretending that people are blank slates with an infinite capacity for indiscriminate altruism. We'll do much better if we learn how evolution designed people to engage in altruism, because this will tell us how we can alter environmental conditions so as to elicit nice behavior. A mental adaptation is, after all, an information-processing, problem-solving device, not a blind biological drive walled off from the environment, and it produces a behavior only in response to environmental cues that tell it what problem is at hand. By understanding how a mental adaptation works, therefore, you can understand how to change its environmental input in a way that will be most likely to produce the desired behavioral output. That doesn't mean that human behavior is infinitely malleable, but it does mean that changing behavior will be easiest for those who best understand the raw material of human nature.

Copyright Michael E. Price 2011. All rights reserved. 

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