Anthropocentrism - the view of humans as central to the universe - is an attitude that is all too common among members of our species. Many have argued that evolution was a goal directed process moving towards, you guessed it, us. Modern evolutionists would frown on this idea: indeed, the notion that we are somehow special is frowned upon, evolution being instead treated as a series of accidents with each organism optimizing itself in the short term to its environment. Yet the desire to find a bright line between ourselves and the beasts persists, and it seems that modern anthropology as well as evolutionary biology have converged on one defining characteristic of humanness: culture.
The ability to transmit information in an abstract sense - e.g., through language - required the emergence of several complex adaptations. Recent theories on the matter have suggested that it was an enhanced ability to imitate movements that came first; there is good reason to suspect that with such a groundwork in place, the evolution of language aptitude was relatively easy. Yet even though scientists are getting closer to defining what it is that makes us human, one thing is becoming very clear: our psychology evolved in a setting far different then the one we live in today, and I would contend that many - maybe even the vast majority - of societal-level problems we experience are a consequence of this.
Modern Homo sapiens is believed to have emerged 190-150,000 years ago around Ethiopia, and left the African continent about 40,000 years ago (there was a brief migration to the Levant around 90,000 years ago, but this appears to have been unsustained). The reasons for this emergence are complicated, but there is a fascinating story of increase in brain size over the last 5 million years across almost all mammals, coinciding with a period of wild climactic variation. To give you an idea, imagine if temperatures fluctuated 10 degrees celcius from year-to-year for a given season - this was the pre-Holocene climate. From all the evidence available, it seems that for the vast majority of our evolution during this turbulent period, humans have lived in small family bands of about 30-50 individuals.
Only about 10,000 years go, with the advent of modern agriculture, did human societies increase in complexity and size. The reasons again are complex, but the basic idea is that the climate miraculously stabilized - temperatures have been amazingly steady over this period, and this presumably made agriculture possible and advantagous to groups, allowing population growth (some food for thought for you global warming buffs). If you think like an evolutionary biologist, you will immediately understand the implications of this idea: our psychology, and our way of thinking, evolved under selective pressures completely different from the ones we experience today. While it is true that we have evolved amazing social abilities, with signaling capacity and emotional nuance far in excess of anything we know, this emotional and psychological tool kit was built for a world of small, tight knit tribes.
Today's world is very different: over the 10,000 years since the advent of agriculture, our population has grown at a breathtaking pace. Today, we live in societies of incomprehensible complexity. Our tribal units - nationhood, religion, occupation, ethnicity - now comprise millions of members. Some small miracles have happened in this context: altruism, long a puzzle to evolutionary biology, is much easier to explain in small groups. It is quite reasonable that we are as nice to eachother as we are not because it is good for our genes, but because it WAS good for our genes, and they just have not had time to change. But some ugly consequences also come out: it has been shown that cultures adapt certain norms for functional reasons, but many are adapted due to randomness (e.g., taking your hat off in church). Thus, if you have a barrier between cultures like language, their norms will tend to deviate, and sooner or later, one group will think the other is "immoral", evil, and ... bombable.
Whoa, you say - that is quite a jump. Let's dig a little deeper though. One of the puzzles for evolutionary biologists has always been culture: the 'hot' idea of memetics has been frowned upon by most scientists, but a few (the most prominent probably being Peter Richerson and Robert Boyd) have made important contributions to the idea that culture evolves much like our genes. One of the problems with cultural evolution is that in order to have evolution, you have to have variation and variation has to be heritable. Richerson and Boyd have shown, using mathematical models, that imitation of others coupled with punishment of deviators will give rise to precisely such a system, making cultural evolution possible. This is very important because if culture does not evolve (culturally) in an adaptive (genetically) way, it is useless from the perspective of the genes and will the capacity for culture not evolve (genetcally) in the first place. These two scientists, and their likeminded colleagues, suggest that much of the more refined human social emotions are specifically designed to drive cultural evolution ... in small, tribal societies.
But when you have societies of millions, the rules of the game change. One of the strongest predictions of the models is the drive toward conformity - too much conformity, and you natural selection will not work (because you will copy no matter what, and cultural evolution works best when you copy selectively the things that "work"); too little conformity, and you have no heritable variation, and hence no evolution (evolution takes three ingredients: mix one part variation in phenotype, one part heritability of this variation, and many parts natural selection, and you have yourself a delicious Evolution Cake). Thus, a happy medium is expected. It is thus quite plausible that there is some degree of genetic control over tendency to conformity. This is not just isolated speculation: psychological work has shown the existence of several behavioral "syndromes", by which I mean not diseases, but rather, correlated groups of behavior that seem to occur together. You probably know this as 'personality type'.
But what are the real implications of all this mumbo jumbo? There are quite a few, but I will begin with a topic that has been in the news a good bit lately, the flare up in violence in the Middle East. I have observed that the tendency of Americans to side blindly with Israel is quite bizarre, and irrational from pretty much any angle I can think of. Hell, it is irrational for the Israelis to do what they do - I opine that a rational actor would, given Israel's strong position, make peace while it dictates the terms and has capacity to make many concessions. Yet this does not happen. Let me propose why.
First, your tribal instincts give many paths to war and far fewer to peace. Israelis and their neighbors are very culturally different: religiously, historically (most Israelis are Western/European in culture), linguistically, economically. This automatically means they will have different cultural norms, and reasons to despise the other side (e.g., Israelis hate "suicide bombers", while many Muslims praise their "martyrs"; some Israelis strongly support the settlers on religious grounds, the Palestinians are not so fond of them). The resulting dehumanization of each side by the other makes further aggression easier, and peace more difficult.
Second, in a conflict situation like the Middle East, emotional traumas will occur on both sides, resulting in positive feedback of hate. If a close friend or relative dies at the hands of an Israeli bomb, or is killed by a Hamas militant on a bus, the body typically reacts with anger. Because you are designed for thinking in tribal terms, you will tend to want revenge. In the context of small tribes, this was surely the evolutionarily advantageous response (indeed, the fact that that is the response is, to an evolutionist, proof that this is the case!) ; there were limited resources and it was survival of the fittest. But in the modern context, it is far from ideal. Our tribes are not small, and they are much more long lasting (studies have shown that in New Guinea, tribes die frequently, with lifespans of 100 years or less - people are not slaughtered, but rather dispersed to relatives in other tribes or absorbed). This would suggest that the wisdom of Jesus, Gandhi, and MLK has deep evolutionary sources: turning the other cheek and not lashing out is the adaptive response in the modern context. It is easy to imagine, from this logic, that such anger-revenge will be a never-ending feedback cycle; this is no new idea.
Third, because of strong loyalty to the tribe, there is little desire to question decisions and actions by the tribe. Thus, Israel is always responding to attacks by terrorists, according to Israelis, while Hezbollah or Hamas are responding to Israeli aggression, according to Lebanese and Palestinians. This whole idea of course is stupid: people are dying, and that really should be all that matters. But our strong sense of vengeance makes this a difficult thing to accept.
Fourth, you will tend to have sympathy for those you know and associate with. America has a very strong relationship with Israel - there are historical reasons for this. For one, America is home to almost as many Jews as Israel (only a year or two ago did Israel have more Jewish people). Many prominent Christian leaders make pilgrimages to Israel, and befriend people there. Strategically, the vital nature of the Middle East and the history of Israel have made American policy elites very close to Israeli policy elites. Thus, we can say that our countries are strongly connected in a cultural sense. No wonder, then, that our opinion is so pro-Israel. Personal relationships matter, especially when they are relationships among the elites.
Indeed, I would argue that our tendency toward conflict and war is, especially in modern nation states, a byproduct of our flawed psychology. We erect artificial barriers between people who, fundamentally, have very similar needs (though their cultures will be different in arbitrary ways). When a conflict does start, it is very difficult to stop, because both sides, due to psychological mechanisms, villify and acquire hate for the other. Of course, none of these ideas are new, but the emerging consensus in evolutionary anthropology is, and the story it tells is chilling.
Another major consequence of societal complexity is stratification. It is known that as group sizes increase, the gap between the most and least powerful widens. This is true not only in humans, but also in animals; large baboon troops will often have several tiers of dominance, while smaller troops will perhaps have just one dominant male. The desire for hierarchical supremacy is not new to humans, yet it takes on quite a perverse form in our modern world. While it is genetically beneficial in smaller societies, this is true also because it imposes a far lower cost to the losers. In essence, there is a tension between altruism and hierarchy climbing, and altruism, according to some models, is only possible when you mitigate the intensity of the hierarchy. Anthropologists have long noted that hunter gatherers have much more equitable (though not at all egalitarian) societies than our own. In this context, altruism makes sense.
But what happens when you have societies of millions, and your likelihood of interaction with particular individuals diminishes to virtually zero? Well, game theory would predict rampant selfish behavior, yet the observed reality is the opposite. Here, again, norm enforcement is key: punishment, when added to the game theoretic models, makes cooperation possible in even large societies. While this is true, the models also show that cooperation is far greater when there is equality, and when you allow people to start off with varying positions of strength, this actually weakens altruism.
So what am I saying, anyways? Well, basically I feel that we have a tendency to paint our political opponents as somehow inherently evil. I do not think so - I would argue that most people think what they are doing is "right". But because of ancient psychological mechanisms, we will be often forced into making very irrational choices, and this will be especially true when we make decisions in contexts for which we were not built. In other words, politics, a real of social exchange involving millions, is a ripe medium for massive mistakes.
And how do we solve it? Personally, I think understanding human behavior will be fundamental in helping us "get over" our problems. This is not going to be easy: if groups are so reluctant to accept an idea so trivially obvious as evolution, imagine how hard it will be to persuade them that their militancy is a pathological condition? But this will have to be done.
We live in a very dangerous world. Already, we are in the process of destabilizing our planet climactically; our magnificent brain, with its capacity for cultural evolution, may save us. Or it may not; I'd rather not find out. In the long term, moreover, our technological capabilities will continue to increase. What this means is that, sooner or later, it will be possible for virtually anyone to kill everyone. If we are to have any shot at surviving as a species, we must begin to break many of our old habits.
Fortunately, cultural evolutionary theory points to how this can be done. For one thing, it is essential to break down barriers. While I am proud of America and her accomplishments, it is proper to always put membership in humanity above any nation. This is an age-old lesson, but modernity may help us accomplish it. With the advent of rapid communication and travel, it may be possible to create a homogenous world. I do not mean uniform, I simply mean a world where nation states start to evaporate, just as they are in Europe. Moreover, much greater efforts will have to be made to bridge the rich-poor divide.
This will, of course, be a long term process. But it is my view that the current condition is untenable; we are simply not built for it, and we must adjust our social institutions in very profound ways to address the shortcomings of our nature. We have come a long way as a species,
and the Enlightenment did, in a sense, embody the ideas suggested here without any need to call for some complex evolutionary ideas. I guess what I am trying to say is that the general sentiment of the "left" is, in my view, supported by the science. If we say our goal is survival of mankind, we must adopt these ideas and push for them; if we accept the worldview of the right, of the GOP, our days on this planet are numbered.