time enough

this is just me cutting-and-pasting a couple of comments from jayman…’cause they’re AWEsome comments! (^_^)

they’re from the discussion to my outbreeding and individualism post, and they’re a response to a question from our resident skeptic (skepticism is good!) jtgw:

“…just a couple of centuries or so. Is that really enough time to effect that much genetic change according to your theory?”

jayman responded here [bolding by me]…

Yes:

“One of the simplest models of directional selection, truncation selection, where the bottom (or top) x% for a trait fail to reproduce is easy to model and produces something that closely fits observed situations.

“Say those 1 standard deviation below average for a trait fail to reproduce – roughly the bottom 16%. (In terms of numbers, this isn’t far off from the fraction of people that fail to reproduce in modern America.)

“The breeder’s equation gives us the selective effect:

“[R = h^2 * S]

“R = response to selection (mean of trait in following generation. S = selection differential (mean of trait of parental population). h^2 = additive heritability of trait.

“If we assume those 1 s.d. below average fail to reproduce, then the mean of the parental population (assuming trait in question is normally distributed) is the mean of truncated bell curve cut at -1 s.d. which you can find (with some…fancy math) to be +0.29 sd.

“Since the additive heritability of most traits is 0.5, the response to selection in that case is 0.29 * 0.5 = 0.145 sd/generation. If this were IQ, that would correspond to a ~2.2 point gain per generation. Assuming sustained selection, the population mean would move one whole standard deviation in just 7 generations (or about 200 years)! I mentioned IQ, but this will work just as well for any quantitative trait with a similar additive heritability, including the personality traits associated with a fine manorial serf – which you [could] model collectively as a ‘manorial quotient’ (MQ).

…and here

The World Values Survey gives us a neat way to quantify overall mean clannishness around the world:

“It’s even mapped in standard deviations.

“Outbreeding has produced an evolutionary shift to the right (maybe to the upper right) for NW Euros on this map. If we assume they started about where the Slavs are now, that means they moved +2 or +3 s.d. over the course of the relevant evolutionary time. Such a change (given the case of strong, sustained directional selection) could take as little as 400-600 years, given the formula above.

and that, dear readers, is how you make hbd chick smile. (^_^)

edit: oh! jayman promises that there’s gonna be more like this in an upcoming mega-post on his blog, so stay tuned!

(note: comments do not require an email. break open the bubbly!)

response to jayman’s post

this is my response to jayman’s post of yesterday, Where HBD Chick’s Hypothesis Works. i was going to leave these thoughts in a comment to his post, but i quickly realized that my comment was going to be pretty long, so i figured i’d just make it a post here. i should just say at the outset that i agree with pretty much everything jayman had to say (^_^) — with a couple of minor quibbles — so this comment will mostly be me rambling about those, plus i’ll be throwing in a couple of “thoughts for future research.” you should definitely go read his post first if you haven’t already before reading my comments. pay attention to his map of how well the hypothesis works in different areas — it’s great! (^_^)

ok. jayman says:

“As we see, from what we know of historic mating patterns and behavior of people today, HBD Chick’s hypothesis works excellently across much of the world. This is especially true across Europe, the Middle East, and much of the Muslim world, and in China.”

yes. on several occasions i’ve wondered if this inbreeding/outbreeding idea really applies mainly, or only, to the indo-european world + the arabs. but the situation of china seems to fit well, too, so i think the general theory is probably more widely applicable (assuming for a sec that it’s correct at all — which it might not be). as i’ll argue below (one of my quibbles), i think the theory might also hold pretty well for japan although Further Research is RequiredTM. (actually, Further Research is RequiredTM for most areas of the world — especially lots of actual genetic/real scientific research!)

more from jayman:

“There are however a couple of places that don’t seem to fit as well. Most poignant of these is sub-Saharan Africa. HBD Chick’s hypothesis doesn’t cover much of Africa, especially the non-Muslim parts. It’s unclear if the historic mating among non-Muslim Blacks was particularly consanguineous (though it was, and remains in many places, polygynous). However, as we clearly know, sub-Saharans do behave like considerably clannish people in some ways, yet a lot more like typical outbreeders in other ways.”

even though i haven’t posted much about sub-saharan africa — yet! — i have been reading up and taking notes on the mating patterns of sub-saharans africans, and let me tell you — there are a LOT of sub-saharan african populations (tanzania alone has more than 120, or more than 260, ethnic groups depending on how you count them! whew!), so, as you can imagine, there is a wiiiide variety of mating patterns on the continent. if i were to make an off-the-cuff guess from what i’ve read so far, i’d estimate that maybe 40%-50% of sub-saharan populations currently practice cousin marriage or did in the recent past (none of them practice the really inbred fbd marriage type of the arabs — except for some northern muslim populations — and even they don’t marry their fbds as consistently as the arabs do). that is just a guess, though. and, then, there’s the polygamy, which also serves to narrow the genetic relatedness in populations, and, so, might trigger similar selection processes for “genes for clannishness” (whatever they might be). and polygamy seems to be very common throughout sub-saharan africa — it’s found almost everywhere (although not everyone can afford to practice it, of course).

the trick will be to try and reconstruct, if at all possible, the historic mating patterns of sub-saharan african populations, especially since historical records for the continent are few and far between. there are historic records for some sub-saharan populations, mainly dating from post-european contact times, of course, and many of them might be useful — a lot of missionaries were hobby ethnographers and recorded loads of cultural data about the people they hoped to convert. genetic data would no doubt be more useful still. (btw, see what i had to say about the mating patterns of african americans and the igbo of nigeria in the comments thread over on jayman’s blog.)

in jayman’s paragraph above, he referenced this old post of mine — civic societies ii — in which i pointed out that the sub-saharan africans surveyed in the world values survey are quite civic, i.e. they are frequently active in voluntary organizations, much more so than peoples in the middle east or eastern europe (see the charts in that previous post). that seems, to me, to be an outbred trait — at least it is very characteristic of northwest europeans. the bamileke of cameroon, too, have a lot of non-familial associations in their society, and they have probably avoided cousin marriage for at least a couple of hundred years.

seven sub-saharan african countries were included in those world value survey results (see this post) — burkina faso, ethiopia, ghana, mali, rwanda, south africa, and zambia — a selection which offers a fairly good regional spread around the continent. i should drill down into those world values survey results to see if i can find out more specifically which subgroups in those populations (if any in particular) were surveyed in each of the countries, and i should try to find out more about the historic mating patterns of those groups. there’s a plan for some future blogging right there!

from jayman again:

“However, farther south in Africa are the San hunter-gatherers (the Bushmen), who were intentional outbreeders, with marriage occurring across tribes. However, overall rates of violence among them are comparable to those found in their Bantu neighbors.”

ack! i still haven’t read more about the bushmen. put that down on the Further Research is RequiredTM list as well!

and this:

“Muslim Central Asia (including the Uyghur province) hasn’t been directly looked at by HBD Chick. But presumably mating patterns there have been similar to the rest of the Muslim world, which would seem to explain the levels of clannishness and corruption there.”

from what i’ve read, the central asians — especially in all of the -stans — tend to avoid any marriage within the paternal clan out to the seventh generation, so in that way they are very unlike the arabs and pakistanis and afghanis. father’s brother’s daughter (fbd) marriage really does seem to have stopped at the edges of the eighth century caliphate. in some regions of central asia, there is also an avoidance of close cousin marriage within the maternal line out to the third generation; in other places central asians do marry their first and second cousins in the maternal line — or have done until fairly recently. this fits with the broader preference of mother’s brother’s daughter (mbd) marriage in asia (where cousin marriage occurs). also, these patterns of avoiding marriage especially in the paternal line, and even sometimes in the maternal line, matches with at least some of the subgroups in tibet. as we saw the other day, first cousin marriage was commonplace in and around lhasa (at the very least) in the 1700s, but has disappeared since that time. perhaps close cousin marriage was also more common throughout central asia and has disappeared in more recent times — or is still in the process of disappearing. dunno. Further Research is RequiredTM.

“India and Southeast Asia also haven’t been discussed much by HBD Chick, either.”

india. *sigh* gotta love india (and indians!) for all of its anthropological diversity, but i have to admit that i have been avoiding india due to the complexity of the mating patterns there. all of those castes!! *sigh* the one very, very general broad pattern that i do know about india right now is that consanguineous marriages are more frequent in southern india than in the north (see the map on consang.net) AND a lot of those consanguineous marriages have been awfully close — uncle-niece marriage is common in southern india — up until very recently (there’s still quite a bit of uncle-niece marriage in the south nowadays, i believe). so, if the theory’s right, then (looking away from the muslims and christians and sikhs, etc., and just focusing on the hindus) there ought to be more clannishness and nepotism and corruption in southern india than in the north. i don’t know if that’s the case or not, but that ought to be how it is. the population ought to be more clannish in the south. similarly, there ought to be more clannishness/corruption/etc. in southern than in northern china — and i do know that clans are more important in southern china than in the north. again, need to try to reconstruct if close marriages were common historically in india and/or china — this should be easier for these populations than for africa since india and china are, obviously, literate civilizations and have been for many millennia.

southeast asia i just haven’t gotten around to yet, unfortunately.

“The Muslim sections of Southeast Asia fit the pattern seen with the core Muslim world, it would seem.”

yes and no. like the central asian muslims — and unlike the arabs/pakistanis/afghanis — the muslims of southeast asia probably avoid fbd marriage. it would be interesting to know if the population of aceh province in indonesia happens to practice particularly close marriage, though, since they have some of the strictest islamic codes of anywhere in indonesia.

jayman again:

“And the Papuan people of New Guinea are famous for being the most tribal people in the world, with the island hosting over *1,000* different languages!

like sub-saharan africans, png-ers have a wide variety of mating patterns! some groups absolutely, definitely have a preference for marrying close cousins while others outbreed. look for a post real soon on some apparent outbreeders from png — the baining!

more jayman!:

“Korea and especially Japan do not fit quite as seamlessly. Japan has had a history of cousin marriage, and the situation in Korea is unclear. Yet neither country is fractured into mutually distrustful clans as is China. Indeed, Japan has a functioning ‘commonweal’ society. However, it is not necessarily like the outbred Northwest Europeans either, possessing some characteristics of a clannish society [those are all unique links in this sentence-h.chick]. It is possible that these countries, like Finland & Iceland in Europe, are also ‘inbetweeners’ of sorts, and possess a distinct hybrid between clannish and non-clannish, as was the topic of my post Finland & Japan.”

yeah. can’t tell you anything at all about korea, because i still haven’t read up on korea yet! (except what misdreavus told me, which is that the upper classes in korea avoided close marriages. interesting.)

japan. yes, japan. japan is probably some sort of “inbetweener” group like jayman suggests — inbetweeners being not extremely inbred (like the arabs) but not being very outbred either (like northwest europeans). japan is apparently not as squeaky clean civic-wise as most of us think, although obviously the japanese are WAY more civically behaved than most peoples! if you look at anatoly karlin’s corruption reality index, the japanese actually score lower than most northwest europeans, and group together with bulgaria, croatia, france, and argentina, as far as corruption goes. and nearly as bad as italy! in 2010, nine percent of japanese people responded that they had to pay a bribe during the previous year, whereas zero percent of danes reported this, one percent of british people, two percent of germans, and five percent of americans. (meanwhile, eighty-nine percent of liberians did! and eighty-four percent of cambodians.) i also had a researcher tell me that, in a study which they conducted (not published yet, i don’t think), the japanese actually scored pretty low on interpersonal cooperation tests — which surprised these researchers. so, something is up with the japanese. they did marry close cousins at a pretty significant rate (ca. 22% — that’s roughly half the rate of sicilians in the early twentieth century) right up into the early twentieth century (see also here). so, i think that the japanese might actually fit the “clannishness” model more than is supposed. they don’t behave as clannishly as the chinese, but they are rather clannish.

jayman had this to say about the japanese and east asians — with which i heartily agree:

“The other possible ingredient could be this: local conditions – often imposed by the State or other local powers – may affect the course of evolution of a people despite the local frequencies of inbreeding/outbreeding. We see this to an extent in China, where considerable genetic pacification – under the direction of the State – served to reduce aggressiveness of the Chinese people despite their considerable clannishness. Perhaps this explains what we see in Japan.”

also this:

“As well, of course, the initial characteristics of the people in each of these areas may have some bearing on their outcomes today, as these traits may affect the precise course of evolution in these places.”

absolutely!

the other populations of the world that jayman mentions that i haven’t discussed (like australian aborigines) i just simply haven’t researched. yet! Further Research is RequiredTM! (^_^)
_____

i’m obviously not the first person to think that mating patterns + inclusive fitness might affect the selection of genes related to social behaviors. that would be william hamilton [pdf]. other population geneticists have played around with the idea, too. in the blogosphere, steve sailer was the first to connect cousin marriage with things like nepotism and an absence of (liberal) democracy in societies — after parapundit pointed out the odd connection between those things in the middle east. even saints augustine and thomas aquinas (and st. ambrose, btw) figured there was probably a connection between mating patterns and the structures and functioning of a society. so does the economist avner greif [pdf], although he doesn’t consider the biological side of it (which is completely ok!).

furthermore, the historian michael mitterauer — who specializes in the history of the european family — understands that there is some sort of connection between mating patterns and family types and size (and the functioning of society), although he doesn’t grasp that the explanation is probably biological either (which is completely ok!). (the more inbred the larger the family; the more outbred, the smaller — i think.) and all sorts of thinkers from engels to weber to durkheim to todd have figured out, in different ways, that family types and structures affect the workings of society.

so even if the specific inbreeding/outbreeding theory discussed on this blog is wrong, i think it’s valuable to examine the mating patterns and family types of human populations. who mates with whom — in other words, the ways genes flow through a population down through the generations — has got to be one of the more important topics in population genetics, afaics! and, at the very least, the prevalence of specific family types in populations must affect selection pressures, since families are a large part of the social environment in any society.

in any event, i just personally find all the different mating patterns and family types interesting! especially in the light of sociobiology. so i’m probably not going to stop blogging about them any time soon. don’t say i didn’t warn you! (~_^)

oh, and very importantly — thanks, jayman! (^_^)

(note: comments do not require an email. albatross!)

behavioral genetics in a nutshell

from jayman!:

(^_^)

previously: it’s not nature and nurture…

(note: comments do not require an email. nutshell.)

personality goes a long way…

in this past sunday’s linkfest, i posted a link to an article about how some researchers found that the ‘big five’ personality traits don’t really seem to apply to some south american hunter-gatherers — the tsimané. i have to admit that i didn’t really pay close attention to the report until jayman commented on it (thnx, jayman!). what the researchers apparently found is that tsimané personality traits don’t fall into a big set of five categories, but rather a ‘big two.’

from the original research article [pdf – pg. 10+]:

“Evidence for the five-factor structure of personality among the Tsimane of Bolivia is weak. Internal reliability is generally below levels found in developed countries. The five-factor model did not cleanly emerge in any of the exploratory or confirmatory factor analyses, and Procrustean rotations did not produce strong congruence with a U.S. sample. Procrustes analysis, which is arguably the most forgiving test for replication of the FFM (McCrae et al., 1996), yielded an average congruence coefficient of 0.62. This is well below the benchmark of 0.90 and considerably less than most congruence scores found in other cross-cultural applications of the Big Five (McCrae et al., 2005; Schmitt et al., 2007)….

“Exploratory factor analysis yields a personality structure that is largely distinct from the Big Five….

“The internal reliability of the first two derived factors in Table 5 (five-factor solution) and Table S1 (unrestricted factor solution) is high, supporting the possibility of a ‘Tsimane Big Two’ organized according to prosociality and industriousness, as described above. These two factors show significant response stability; response stability for the first derived factor is stronger than for any of the Big Five…. However, these Big Two are not the two higher order factors of Digman (1997), characterized as stability and plasticity by DeYoung (2006), which neatly subsume the Big Five by merging Extraversion with Openness and Agreeableness with Conscientiousness and Neuroticism. Our factors instead cut across the Big Five domains. These results are consistent with the findings of Ashton, Lee, Goldberg, and de Vries (2009), where higher order factors emerge because lower order facets load onto multiple factors. Not only do we find that items load onto multiple factors, but the loading coefficients in our exploratory factor analyses are generally lower than those found in previous studies of the Big Five.

“Our findings provide evidence that the Big Five model does not apply to the Tsimane. Our findings also bring into sharper focus past reports from developing societies where the FFM was not clearly replicated. Of the 50 countries reported in McCrae et al. (2005), only India, Morocco, Botswana, and Nigeria produced average congruence scores less than 0.90. The lowest congruence scores reported by McCrae et al. are 0.53 and 0.56 for Openness in Botswana and Nigeria, respectively. In the African and South Asian countries from Schmitt et al. (2007), internal reliability for Extraversion, Agreeableness, and Conscientiousness is similar to what we report for the Tsimane. Because the samples from the developing countries in Schmitt et al. and McCrae et al. are
primarily college students, more representative samples from these countries may have produced even lower congruence scores and internal reliability.”

so, the big five maybe don’t fit some other populations, either! hmmmm. curiouser and curioser.

again, i have to admit that i haven’t thought very much about this, but i feel kinda dumb right now in that i think i’ve been forgetting first principles when it comes to these personality things, namely, human biodiversity! why should we suppose that all human societies everywhere will fit into the big five categorizations? we shouldn’t be assuming that at all!

but jayman’s already neatly summed up the problems with personality research and hbd, so there’s no need for me to repeat what he’s said:

“While the HEXACO model is interesting, and certainly feels more ‘complete’ than the Big Five, I will say that personality research in general still has a *long* way to go, hence I don’t put too much faith in such models (or most ‘models’ in social science, for that matter). A big part of the problem is that too much of psychological research has been done on WEIRD people, and even then on the segment of those who are college students, and this has been a major stumbling block in trying to gauge the gamut of human behaviors….”

just to note, in the tsimané article, the researchers point out that “most studies of the FFM have been restricted to literate, urban populations, which are uncharacteristic of the majority of human evolutionary history.” they also say that their study of tsimané personality types using the five-factor model is the FIRST done on an illiterate, indigenous society. oh, dear.

more from jayman…

“HBD Chick, more than most, has demonstrated the importance of sometimes very specific behavioral traits, which are quite heritable. Muslim honor killing is one such example (where does that fit in HEXACO?). It’s very clear that standard personality tests do not capture heritable behavioral traits that are of great significance.

“Indeed, it may turn out that it may not be possible to boil down human behavioral traits into simple dimensional systems because the range of behavioral traits is so great, and encompasses behavioral responses designed for fairly specific situations (which sounds almost like a sacrilege coming out of a reductionist like me); for example, how does one account for the ideological divide between libertarian liberalism of Anglo societies and collectivism/communism of Eastern Europe and China on the other (a divide, which, itself, is really only relevant for highly organized societies with a long history of civilization and agriculture)?

“Perhaps one day they’ll cook up a system that can broadly encompass the range of behavior, but that day is not today.”

(note: comments do not require an email. tsimané fellow.)