A clarification on the post below, when I talk about the spread of 'monotheism' I'm talking about the outward spread of groups who espouse an Omni-god. I'm not talking psychologial monotheism, I don't think it makes much sense to really distinguish it from polytheism. To be frank, the Omni-god monotheisms have many gods, some of them are called angels, others are called saints, and in the case of Christianity there's a lot of smoke thrown in the air about the Trinity which is a mystery to all involved. Some might consider Buddhists to be a non-theistic group which is fundamentally different from the Omni-godists. Well, a few years ago I read an article about the aftermath of the Indian Ocean Tsunami where Therevada Buddhist peasants in Sri Lanka explained how their Muslim neighbors were adversely affected by the catastrophe because they didn't accept Lord Buddha. Sound familiar? The Buddhists in question didn't seem to find it relevant that in that locality Muslims were fishermen who live don the coast while Buddhists were inland farmers. Buddhism, the religion of rationality?

So you see, Buddhists do believe in god, they just call it Lord Buddha, or a Bhoddisatva, or some such other thing. Yes, Muslims are monotheists, but saint worship and veneration of Sufis is pretty common in the Muslim world. Hard-core Omni-godists like the Salafists have to take drastic measures like destroying the tomb of the Prophet Muhammad to really batter away at human instincts. Omni-godists sincerely profess a believe in All-god of All-things and All-times, but that sincerity is as relevant as being sincerely convinced that an 8-dimensional Peacock Asteroid is lord of the world. It could be true, but whatever. Hindus might traditionally believe that the godhood is immanent in all things, but they never worship toilets or turds, rather, they focus their spiritual energy on the concept of a god out their, or embodied in an avatar, often using imagery as foci.

Elite religious professionals and the ruling castes need ideology. There is basal religious sentiments which most humans exhibit, so this is good raw material to synthesize with ingroup-outgroup markers. Add a few demarcatory rituals and shibboleths, plus magical words of a sacred nature that are incomprehensible to all, and you have a good recipe for an epidemiologically potent complex of ideas. We know it's potent, higher religious imbued with philosophical baggage and ideology have become dominant in our world. The elites with leisure time like philosophy. The masses are attracted to religion, the beliefs, the rituals, the communal bonding. Mix the two together and have a dragon with a head, philosophy and ideology generate a systematic superstructure through which the religious passions which have always existed by can channeled.

So, back to the question. Why did exclusive universalistic monotheism succeed in Western Eurasia and not Southern and Eastern Eurasia? Here I'm not asking about differences in psychology, European peasants were operationally pagan until the Reformation. There is enough ethnographic literature in places like Germany in the 18th century which show almost immediate reversion to paganism (without knowing what they were doing) by peasants who are without a pastor to "guide" their thoughts. This is why I reject Theresa's idea that European natural individualism was somehow attracted to monotheism because it of a good fit between ideology and psychology, I've already established that the two don't really match at all, there's little variation between groups on the latter, a lot on the former. Also, in any case the the most individualistic European groups were the last to monotheism, and the first to post-Christianity (and operational re-paganism, starting with an abortive attempt in Nazi Germany), so that doesn't work either The most monotheistic groups are in the Middle East, but it seems that a more parsimonious explanation is simply that Omni-godism spread outward as a function of distance from the Middle East.¹ Mousy Matt pointed out that the probability of extinction of any given introduction of a favored mutant is rather high. In other words, if Christianity (to use an example) was introduced by the immigration of one individual to China the chances of propogation might be higher than !Christianity, but that doesn't mean that you are probably going to see it go extinct. So I asked Mousy Matt, "what's the level of selection?" The reason is that in Tang China between 600 and 850 (which a religious pogrom rendered extinct most "foreign" religions and reduced in power "indigenous" ones) Christians were a non-trivial presence in the cities. Christianity showed up again a bit during the Mongol period (some of the Mongols were Christians), and again during the late Ming period, and finally again during the 19th century. So does each introduction count as a mutational event? But what about the dispersion of Christians to the various cities of China? Isn't each loci a potentional point of protonation? Finally, there's another Omni-god religion, Islam, which has pretty solid roots in China, and has had them, for nearly 1,000 years. There is some evidence that Chinese lineages in parts of South China were even originally Muslim before full assimilation into a Han identity.

OK, enough for now. I guess the point is that our model can't be one where Omni-god meme complexes float on top of an invariant background fitness level which they have an advantage over. In places like China and India their fitness is constrained, even nullified, by sociological factors. It isn't like Chinese can't become Christian, most Chinese in the United States, many in places like Indonesia, are Christian. When the constraints are removed and the fitness landscape is altered (e.g., becoming Christian was a good way for a Chinese individual to prove that they weren't a Communist in Indonesia) it is a different ball game.

1 - The monotheistic explanation can be tested in East Asia, there are two nations with many Christians, South Korea and The Philippines. I think it can be argued that Filipinos are rather individualistic, and sociologial data shows that Korean Christians are more liberal and individualistic than non-Christians. But both these effects are hard to tease apart from the influence of Spanish and American culture respectively.