It makes women smarter? How, how much?
Shades of Camp Concentration.

Document not found.

Doesn't surprise me a bit. Hell, sexual reproduction came about due to viri. Most people greatly underestimate the selective forces of viri as compared to the macrobiophysiological (I hope that's a word) environment.

I looked at the list with political history in mind. I was remembering William McNeill's Plagues and Peoples, in which he suggested that blood flukes (found in Sumerian remains) kept the people sluggish and submissive - and suggested that less infestation by such parasites was the reason our libertarian traditions had to arise in Europe, not the river valleys.

I don't know whether the idea has gone anywhere since McNeill wrote the book (if someone does know, and has a link handy, I'd be grateful). This table doesn't support it...at least, the people famously submissive to authority (Japanese, Chinese, modern Scandinavians) have relatively low rates, and Jamaicans (not famous as a quiet, submissive people) have a very high rate.

This gives you an idea of how observations of "national character" may change over 100s or 1000s of years, and yet be at least ballpark-correct at each snapshot in time. Imagine a more extreme case where half the adult population has syphillitic neurosis, and during 5 to 10 years a ministry of public health is founded, whose main aim is to promote safe sex. It surely takes longer for Germany to become more densely populated than Norway, but we're probably talking w/in the past 10K years (or even recorded history; I don't know my demography so well).

So, in addition to introducing cultural innovations or outright novel germs, a group that's had no contact w/ another group could also introduce a cultural innovation that later results in greater exposure to an already present germ. Let's say one style-setting group introduces a vogue for not thoroughly cooking meat -- or, say, for not practicing hygiene at all (drop-out hippies). Or introducing eating utensils instead of touching your food with hands that've been god knows where.

Newer approaches to personality traits, like Extraversion, try to integrate them w/in cognitive science -- conceived as "If/Then" programs: "IF you find yourself in a large group of people, THEN freeze, exit conversations ASAP, move toward the periphery, etc." Or the classic "hawk and dove" could be rephrased in Big Five terms as "disagreeable vs agreeable." In this "cognitive" form, they're no different from the alternative strategies in evolutionary game theory. Depending on the payoff matrix (which presumably has a large cultural influence, thus varying from one place to another), there will probably some sort of frequency-dependent dynamic. But this would also be true for parasites that re-program their hosts so that they adopt strategy X or Y.

So, some of what looks like frequency-dependent selection in humans (well, at the phenotypic level -- genomic assays could tell you if this were due to changes in human allele frequencies) might actually be changes in allele frequencies in parasites. And then there's the paper-rock-scissors possibility -- talk about cycles of history!

Having read the paper completely, all I can say is that T gondii seems like a feminists dream. It seemingly makes men more like women and women more like men.

I also note that there are some weird differences in infection rates. Japan is about the same as the US, and the UK and Norway are very similar.

What immediately struck me about the data was that the English are famous as cat fanciers, yet their infection rate is second lowest overall after South Korea, and lowest in Europe. The only other county in Europe that comes closest to their low rate is Norway, most other countries have many times the infection rates.
So what's going one here?
Is it possible that the English have developed some resistance to T. Gondii?? Is it possible that the infection rate is also related to the types of rats that live in the locality?
I know in Ireland up till 200-300 years ago the Black Rat (rattus rattus) was the main rat in the country, but today is largely replaced by the Brown Rat (rattus norvegicus), which as the name suggests originated in Norway. Is it possible that a similar pattern of replacement happened in other parts of Europe and that Norwegians, and related populations are less susceptible to T Gondii, due to their ancestors living with this rat for longer??

england is cold and less rural (fewer farmers) perhaps.

OK, maybe I got t. gondii.

Ca't figure it out. the Fegr paper said that the means on Cattell factor B were 8.32 for unifected women and 8.93 for infected women. Can this be converted to IQ? Did women actually get smarter, or only think they were smarter? Increased confidence is different than increased intelligence.

Having read the paper completely, all I can say is that T gondii seems like a feminists dream. It seemingly makes men more like women and women more like men.

That's funny, a while ago I read another paper on the same parasite that suggested to me the exact opposite. It said that in men infection correlates with increased aggression and unwillingness to conform to societal norms, whereas in women it correlates with increased agreeableness, sociability, and concern for personal appearance. The other article also mentioned the increase in intelligence for women and the decrease for men, which was the only thing that did not fit into this picture.

This new article seems to replicate the agreeableness increase in women, but the effect on men seems to be almost the opposite of what was previously said. In any case, I really wonder how significant the effect of the parasite is on personality.