NuSapiens has a post addressing differential performances of diverse and non-diverse groups. This is an important issue. In modern American culture there is literally a Cult of Diversity, a general assumption that Diverse ~ Good. But, “Goodness” is more predicated on moral considerations than utilitarian ones. It seems highly plausible that in group tasks commonalities are more likely to lead to fewer confusions and misunderstandings, that diverse groups which are not always on the same page will suffer even if individually they are superior specimens on any given task. As a historical example, consider the Roman armies that marched against the Celts. I would hazard a bet that a grain fed Roman was not as “fit” a warrior, on average, as a Celt who had a more diversified diet and likely a genetic predisposition to be taller in any case. Nevertheless, disciplined and well organized Roman legions cut through barbarian tribes like scythes, because the latter had far less group coherence. On the other hand one can imagine other scenarios where diversity is essential to group success, for example, during the Roman general Agricola’s march into Scotland it would have likely aided him if he had some native levies so that he could communicate with possible allies and have a better sense of the lay of the land. Even if the native levies diminished the seamless integration of his fighting force, they would be useful in other circumstances, their linguistic and cultural fluency could aid in maximal force projection and deployment.
This highlights what I think is an important point when it comes to conceptions of “diversity.” In the United States it is often assumed that “diverse” ~ multiracial. But, that does not take into account linguistic, religious diversity, political diversity or economic diversity. A consideration of linguistic diversity brings home the downsides rather forcefully. Additionally, an examination of different variables can lead one to disparate conclusions. For example, it is well known that Japan and Korea are very homogenous nations. Nevertheless, because of a small, but non-trivial, number of Korean Japanese, and foreign laborers from various parts of Asia as well as Japanese Brazilians, Korea is often judged to be more homogenous. But that neglects two crucial points.
Korea is far more religiously diverse (1/2 nonaffiliated, 1/4 Christian, of many denominations, and 1/4 Buddhist).1Korea has a far more vital political party system.
Despite the fact that Korea is racially homogenous almost to unity, I would argue that on the whole based on macrosocial metrics it is likely to be characterized by more anomie than Japan2
1 – Both Japan and Korea have many “New Religions,” and you could likely get different results based on how you calculated religious diversity. But, while over 90% of Japanese have an apathetic affiliation with their national Shinto cult and Japanese Buddhism, the Koreans have several large religious groups of similar size.
2 – Some of you might be curious has to how genetically diverse the Japanese and Koreans are. My impression is that there isn’t that much data in on this on that level of granularity (though if someone is willing to do a PubMed search I’m willing to post an addendum), but it is noteworthy that it is likely that the Japanese are a hybridized population, with about three parts Korean and one part Ainu. Of course, the former would be a subset of Korean genetic diversity, while the latter would increase the heterozygosity on many loci because the Ainu (Jomon) are an outgroup to the Yayoi and Korean source population.
Posted by razib at 12:50 PM