U-M study helps define why fewer women choose math-based careers, the reason? Women have different priorities than men. This sort of data has been floating out there-I remember reading about a study where they tracked very mathematically precocious early teens and found that the boys were far more likely to enter Ph.D. programs that emphasized math. The girls on the other hand (a minority of the original sample to begin with) focused on medicine, law and other high-powered professions that would earn them more money than becoming an engineering professor.

On a related note, I was talking to a friend recently about how relationship discussions with guys and girls are so different. If I tell a male friend that he should break-up with his g/f because she’s not right for him, he will respond with brevity, “OK, sure,” or “Dude, shut-up.” On the other hand my female friends tend to ask detailed questions about why, when I formed this opinion, what my motivations might be, and so forth. In contrast, when I suggest that a friend needs a wireless card for their laptop, girls will be “OK,” or “Can’t afford it,” but a guy will start to ask in detail what the context is, the various standards, what the ramifications are in terms of the utility of lugging around a desktop replacement, will that entail the purchase of a router, etc.

My point? We’re different. As individuals. As genders. As groups. Is that so wrong? Each individual makes decisions and excessive focus on aggregates can get you lost in the forest when the trees are really what’s important. The flip-side is that we can’t ignore the aggregate if we’re looking at social policy. As a libertarian, I tend to favor less public social policy, and more private acts and civil society, but since I have to engage with people on the Right and Left that believe in the utility, the necessity, of government intervention and evaluating groups, I do speak in the language of aggregates.

Backdate from Jason S
A while ago, John Quiggin had an interesting take on the paucity of women economists which uses a math-preference related argument. GNXPers might not necessarily agree with his nurturist perspective but the rest of it re what’s required in Undergrad vs Postgrad Econ holds true:

In undergraduate economics classes, students with the ability to write a coherent and grammatical sentence are rare enough that it’s possible to do quite well without the kinds of formal reasoning skills that are most naturally acquired from doing maths.

But the further you go the less true this is. At the graduate level, lousy prose will be forgiven but inadequately formalised arguments will not (at least, not until you’ve established your credentials with enough of the formal stuff that you can get away with leaving out the details). So the forces of comparative advantage encourage bright women to leave economics and move to fields where their skills are better rewarded.

I’m a big fan of liberty, my personal political orientation is pretty much libertarian, but I have resigned myself to the fact that libertarianism, along with atheism, rationalism, etc. are oddball norms & views that will never really convince the majority [1]. So I’m glad to see that someone is trying to get libertarians to move to a small state and pool their power. Check it out, The Free State Project. Ex-GNXPer and Lady from Gotham Diana Moon once asked sarcastically that all libertarians should move to the Dakotas and we can have our libertopia there. Well actually…I thought at the time, “sure,” why not?

This nation, this republic, was formed at a time when fewer than 10% of the eligible males in a population of 2.5 million could vote and intermediary institutions were far more powerful (the Senators were elected indirectly through the state legislature, etc.). I am personally skeptical of the scalability of the republican project to 300 million individuals-especially when evolutionary pscyhology tells us that the average human can’t really keep track of more than 150 people as fully-fleshed personalities.

More on this later….

[1] My political factionalism has waned as my concern for the safety and health of western liberalism has grown.

Props to US NEWS & WORLD REPORT for reporting on the plight of the Mandaeans, also known as the “Christians of John the Baptist,” who practice a gnostic flavored faith in southern Iraq. But, shame on them for not using fact checkers, divorce is not forbidden in Islam.

Posted by razib at 03:23 PM

Hey, this brown kid won the National Spelling Bee. Another brown kid won last year, so I did a quick survey of the ethnicities of the contestants to look for patterns. This is what I found (I clicked to see every image and read up a bit to get clues for the ambiguous):

White, 167
Brown, 24
Arab, 4
Latino, 14
Black, 4
Asian, 29
Mixed, 5
Pacific Islander, 2

I put Southeast Asians with the East Asians under the “Asian” category-including Filipinos with Latin last names. Most of the mixed seemed Eurasian. A lot of Asian adoptees (European names) were in among the contestants.

Go see the contestants here.

Update from Jason M: Hey kids, get out your calipers – the New York Times muses on the Geography Bee gender gap:

With students left to their own devices, a geography gender gap has become evident, so wide that with five million students participating in the bee, about 77 percent of the school winners are boys…

…Why the geography gap endures, some researchers say, has something to do with the fact that most schools are still not teaching the subject, and something to do with the toys geared toward boys and other social influences.

But mostly, they say, the gap stems from cognitive differences that give boys better spatial skills than girls. The same advantages that help boys in the geography bee make them, in general, better at navigation and finding their way.

[via Chris Brand]

In the entry under “weird,” the Moken “Sea-Nomads” that inhabit the inter-tidal region along the Burma-Thailand coast seem to have better underwater vision. Please note that the Moken might be among the earliest inhabitants of southeast Asia, so they’ve had a long time to get used to the ocean (perhaps they are the remnants of the southern wave “beachcombers”).

This research press release from the University of Rochester is very interesting. Titled “Action-Based Video Games Enhance Visual Attention,” here is the introduction:

Research in the upcoming issue of Nature demonstrates that action video games can give a person the ability to monitor more objects in their visual field and do so faster than a person who doesn’t play such games. The study by researchers at the University of Rochester suggests that in addition to making game players more aware of their surroundings while performing tasks such as driving, action game playing might be a useful tool to rehabilitate visually impaired patients or to train soldiers for combat.

“Players can process visual information more quickly and can track 30 percent more objects than nonplayers,” says Daphne Bavelier, associate professor of brain and cognitive sciences, and member of the Center for Visual Science “Several game players even achieved perfect scores on tests barely doable for non-game players.”

Some have suggested that this sort of sensory enrichment might account for some of the Flynn Efffect. Slashdot of course posts these sort of stories all the time….

After recent discussion of cultural evolution I realised that I didn’t know much about memes, so I set myself the penance of reading Susan Blackmore’s .

It turned out to be a painless penance, as the book is well written and full of interesting ideas. Blackmore doesn’t overstrain the analogy between memes and genes – in fact, she stresses the differences more than the similarities. She believes that the ‘key innovation’ of the human species is the ability to imitate. True imitation is rare among non-human animals, and the range and quality of human imitation are unique. The ability to imitate presumably first evolved because it conferred a genetic advantage, but once the ability had emerged, it created a new selective environment in which genes and memes co-evolve. Blackmore also emphasises that sexual selection would favour the best imitators, and argues that ‘the specific nature of the memes of the time would determine which genes were more successful. The memes began to force the hand of the genes’ (p. 79). Using this concept of ‘memetic
driving’ she attempts to explain the main features of human evolution, including the expansion of the human brain and the emergence of complex language. She goes on to consider major areas of cultural evolution such as sex roles, altruistic behaviour, and religion. Finally, she has some bold ideas about the construction of personality and the ‘self’ as a product of competition and selection among memes in the individual brain.

For all that, I still don’t find the book convincing! This is partly because the analysis of specific cultural traits is naive and superficial. For example, before discussing the celibacy of the (Catholic) clergy in print, one should at least read some ecclesiastical history to find out when, where, and how the rule of celibacy was established. In fact, it wasn’t generally enforced until the eleventh century, as part of the medieval Papacy’s campaign to impose central control over church appointments and property. This had more to do with politics and economics than anything covered by ‘memetics’.

Blackmore’s arguments about ‘meme-gene co-evolution’ are also sketchy and hand-waving. Her rhetoric implies that memes ‘drive’ the genes contrary to natural selection, but if this is really what she means, she needs to spell the process out more clearly. There is no problem if she just means that the products of imitative behaviour create new selective pressures for the genes, any more than there is a problem in the fact that once birds start making nests this imposes new selective pressures for nest-building. But she seems to intend more than this. She relies heavily on sexual selection (by female choice) to promote the ‘meme-favoured’ genes, but the theory of female choice is notoriously tricky (see the discussions in P. Bateson (ed.) Mate Choice, and M. Andersson, Sexual Selection). And there is no guarantee that what works with genes carries over to memes.

Consider especially the ‘Fisher’ process of evolution by female choice. First, we assume that a small but significant proportion of females have somehow acquired a genetically-based preference for males with a certain genetically-based trait. Provided there is some degree of polygyny in the mating system, the preference will give that trait a selective advantage. Females who mate with the favoured males will have offspring who often have genes both for the female preference and for the favoured male trait. The male offspring will often carry (but not express) the gene for female preference and pass it on to their own daughters. And since males with the favoured male trait have higher fitness (and therefore more daughers) than those who do not, the gene for female preference will increase in frequency. And so on, and so on.

But a crucial part of this process depends on males carrying unexpressed genes for female behavioural traits. While this is no problem for genes, it is far from clear that the same applies to memes. Genes can be recessive or sex-limited (expressed in only one sex), which on the face of it is impossible for memes. Why should women have the same memes for sexual preference as their fathers’ mothers, and not those of their own mothers or their mothers’ mothers? Yet Blackmore discusses the ‘Fisher’ process without showing any awareness of these problems, and I am not convinced that she has thought the implications through in detail.

Still, it’s an important book, and well worth reading. Overall, it left me with the feeling that memes do need to be taken seriously, but only as one aspect or dimension of cultural evolution. I suggest that in looking at any cultural trait we should consider at least the following aspects of it:

Historical: what do we know about how the trait has actually emerged and developed?
Economic: what are the costs and benefits of the trait, and to whom?
Evolutionary psychology: how does the trait relate to our ‘basic instincts’, such as sex and status?
Social system: how does the trait fit in with other aspects of the society in question? E.g., if the trait is dowry-giving, one needs to look at the whole system of marriage, property and inheritance, but without the ‘functionalist’ assumption that the trait must serve some purpose in maintaining the system.
Memetic: what characteristics of the trait may enhance its memetic survival and replication? What advantages may it have over rival memes?

DAVID BURBRIDGE

There is an interesting study in a recent issue of Science:

Science, March 7, 2003, vol. 299, pp.1582-85: Daniel Falush et. al.: Traces of Human Migration in Helicobacter pylori Populations (and commentary by Brian Spratt at pp. 1528-9).

Helicobacter pylori is a bacterium that lives in the human gut. It is transmitted mainly by prolonged physical contact, especially from mother to child. Within the gut, different strains of the bacterium recombine freely with each other. The phylogeny of the bacterium should therefore track the phylogeny of the human host population, diverging when different groups are separated, merging when they are united.

Falush et. al. have used analysis of Helicobactor to trace a number of important human migration events: the Polynesian colonisation, the spread of the Bantu in Africa, the occupation of the Americas, and so on. The results are generally consistent with genetic analysis of humans (Cavalli-Sforza, etc.). For Europe, the results are difficult to analyse, because there has been considerable mixing between groups of different origins. The authors however believe the European strains probably originate from two main sources, one from the direction of central Asia and one from the Near East and North Africa.

The commentary by Spratt is cautious about the prospects of resolving controversies about human ancestry with Helicobacter. The method is mainly useful when groups have been isolated for long periods (like the Maoris), but more problematic when populations have mingled. However, Spratt suggests that the statistical tools devised for the analysis may also be useful when applied directly to human genes, and not just bacterial ones.

DAVID BURBRIDGE

Posted by David B at 02:39 AM

This NY TIMES article about Evangelicals contemplating the conversion of Muslims is interesting. As an atheist from a Muslim background I think that a collision between these two fundamentalisms is all for the good if it damages both. Additionally my personal experience with many Evangelicals is that they are intellectually not sophisticated and their understanding of which ever “Enemy” they have in their sight at the moment is usually shallow (speaking as an atheist, I’ve been involved in with discussions with theists who barely understand where I’m coming from, but tend to parrot back talking points learned in church when the pastor was preaching to the choir) [1]. Though the article makes clear there is some nuance among Evangelicals in their attitudes toward Islam, the “foot-soldiers” are generally much more blunt and rough-hewn in their conception of the opposition than the theologians, and this lack of genuine clarity (the preconception with stereotypes) will make attempts to convert Muslims pretty futile in my opinion. On a final note, this sort of hubristic attitude toward unbelievers is exactly what I saw in mosques in the United States as a child, though Muslims are very sensitive about Christian missions targeting them, even in the United States, unlike the Hindus and Jews that have been similarly focused upon, they as a proslyetizing faith are being a bit disingenious when they argue for pluralism of belief.

Randall Parker comments on this article over @ Para Pundit.

Update: Reason puts the situation in perspective.

[1] I heard on NPR a few years back a writer who had studied the Christians of the Near East recount how southern Evangelicals who visit the Holy Land sometimes are surprised about the presence of indigenous Arab believers. One of his contacts, a Christian of Armenian extraction who worked as a waiter, always bristled when American Evangelicals with heavy southern accents asked him when he had “converted to Christianity” when they saw the cross he wore. For those not in the know, Armenians like to assert that they were the nation that first accepted Christianity as the state religion, not Rome.

Large DNA File to Help Track Illness in Blacks.

Saying black people are in danger of being left behind at the newest frontier of medical research, Howard University plans to create the nation’s largest repository of DNA from African-Americans.

The samples would be used to find genes involved in diseases with particularly high rates among blacks like hypertension and diabetes.