In Genghis Khan and the Making of the Modern World the author tells of the decision to kill all the adult males of the Tatar tribe and adopt their children and women into the Mongol nation after the former had been defeated by the latter in war. When reading this sort of thing, I could not help but think that this was the sort of decision that resulted in the fact that today 0.5% of men are direct male-line descendents of a Mongol who lived about ~1000 years ago. Additionally, the author emphasizes the fact that the Mongols had little sympathy for local elites, the implication being that “The Golden Family” (that is, Genghis Khan and his descendents) engaged in elite takeover across a vast swath of Asia.
Obviously this particular Y lineage was socially selected for. Both the Manchus and the Timurids, who were the ancestors of the Moghuls, consciously intermarried with the descendents of Genghis Khan to bolster their pretensions toward imperium (though this would have involved the marriage of non-Genghiside males with Genghiside females, so this would not be part of the spread of the haplotype in question). But after reading Game Theory and Animal Behavior, and in particular the chapter by David Sloan Wilson on machiavellianism, I wonder if more directly functional genes related to personality could have spread via selective sweeps through societies. Wilson considers whether “High Mach” and “Low Mach” individuals could exist in an ESS within a population. He tries to relate this to group selection, which I am skeptical of, but the range in personalities within human populations (a non-trivial minority are “introverted”) seems to beg the question whether the fitness of any given type varies a great deal as a function of time, so that the frequencies of the various alleles on any particular locus can never move toward fixation through selection or drift (that is, polymorphism is maintained).
So, cutting to the chase, what kind of personality makes one a World Conqueror? Here is a common definition for a High Mach: charming, confident and glib, but also arrogant, calculating and cynical, prone to manipulate and exploit. Does this describe what we know of Genghis Khan? I am not so sure, the book I refer to above takes a positive view of the Mongols, nevertheless, one common feature of Genghis Khan’s personality that I have seen noted was the value he placed on personal fidelity and honoring contracts. That is, Genghis Khan seems to have emphasized Tit-for-Tat values, when cities surrendered or his ambassadors were respected, he treated everyone involved fairly or with respect, but when faith was broken and cities rebelled or delegations sent under truce were injured or killed he would unleash the wrath of god upon his opponents (he would accept turncoats to his cause, but would sometimes reject them if they betrayed their oathbound leaders in a particularly disloyal fashion).
Variation of personality types through all populations of modern humans makes one wonder if the various traits might have fitnesses that differ depending on environment. Perhaps intergroup differences in the frequency of say High Machs and Low Machs might exist because of long term ecological & social differences. It is the long term part that is difficult, because most human populations have had to deal with dynamic and changing conditions, as evidenced by the mix of individual personalities within any group (though perhaps Wilson’s group selection theories or introversion and extreme extroversion being perpetuated by balancing selection for the modal type could explain the mix).
But, to those who emphasize the Great Man theory of history, I must ask, why is it that the Huns, Turks, Arabs, Mongols and Manchus produced the Great Men, while other “barbarian” groups like the Yakuts, Hmong, Toda and Berbers did not? Clearly, the circumstances of geography and social environment are important variables that determine the likelihood that a Great Man will express world changing capacities and be the focal point for social & political changes of historical import. But, seeing as how the steppe peoples of Central Asia tended to produce Great Men regularly between 400 CE and 1700 CE, one might look to these people to see if their psychological profiles tend to be characterized by a different distribution than the more settled peoples of the Eurasian periphery.
Posted by razib at 12:10 AM