|MadSci Network: Genetics|
Hi Forrest, That's an interesting question you pose. Paraphrasing your question, is xenophobia instinctive? Ever since Darwin, questions of this nature have popped up, and are usually grouped under the topic of social Darwinism. Just as physical traits can experience selective pressure, so can behavioral traits. I will do my best to answer by exploring a few concepts in behavioral evolution, with regard to the interplay between genetics and culture in behavior. One of the central tenets of evolutionary theory is that heritable traits which increase fitness will tend to increase in frequency. That is, traits in an individual which increase the number of progeny that survive to adulthood will be postively selected. Some species produce a large number of offspring but invest relatively few resources in each individual offspring (sea urchins, many fish and amphibians). These species tend to show few if any caretaking behaviours. Other species produce a small number of offspring per generation and invest large amounts of energy in raising them to adulthood, including many birds and mammals. Generally, the longer the period between birth and independence, the more complex the caretaking behaviors. Now, when it comes to humans, we have just about the longest period between birth and independence on the planet. So we have developed many instinctive behaviors to protect our children. I'm not just talking about the so-called "maternal instinct", but about the desire to cuddle and protect babies in all of us. What's so attractive about babies? They tend to have small noses and mouths, and big eyes. It's not accidental that the modern teddy bear has a shorter muzzle and bigger eyes than early teddy bears, and neither is it a surprise that human Disney characters have bigger eyes and smaller noses in each passing movie. Both of these trends show an instinctive human attraction to neotenous traits, and from an evolutionary perspective it has been critical that we (humans) protect and nurture our chidren, so there is good reason for some genetic component to this behavior. So what does an attraction to babies have to do with xenophobia? Well, just as there are probably some instinctive behaviors, it is obvious that many of the traits that have been selected for in humans are culturally transmitted, not genetically. That is, developing the talent to fashion knives, axes, and arrowheads from rocks undoubtedly had a large role in the success of modern humans, but it's not in the genes. The hunter/getherer's toolkit was culturally transmitted. Humans have traditionally been a tribal species: a solitary human probably wouldn't have been able to survive the dangers of the African savannah. When resources were plentiful, there would have been little competition between neighboring tribes, but in times of scarcity there would have been competition between neighboring tribes. The weaker members of the more successful tribes would presumably survive, whereas the weaker members of losing tribes probably would not. My point is simply that in the context of human evolution, competition between groups of humans has probably been at least as important as selective pressure from predators. As such, behaviors which favor one group over another might have been advantageous. So I'm sure that xenophobic behaviors have offered an evolutionary advantage at times. However, just because there has been an advantage to xenophobic behavior at times does not mean that such behavior is so uniformly advantageous as to become genetically based. Although it is possible that there is some modest genetic component, I think cultural transmission is likely much more important. Using another example, small behaviors, like anxiety when we hear a wailing baby, probably have major genetic components, but complex behaviors, like how we react to the distressed infant (singing, cuddling, Ferbering), undoubtedly have an overlay of many cultural components. In conclusion, I think there may be some genetic components to the simple behavior of stranger anxiety, but the cultural components of how we behave in reaction to these feelings are much more important in the context of modern racism, and these culturally transmitted behaviors can be consciously altered. In the modern world the boundaries between tribes are fast disappearing; when our tribe is our neighbors and coworkers from around the world, not our cousins, xenophobic behaviors are simply no longer advantageous... Chris
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