Friday, August 04, 2006

How cats control the world

LiveScience.com - Study: Cat Parasite Affects Human Culture

Regular readers know that this is a favourite topic here - the dreaded Toxoplasma gondii that may drive people mad.

This report suggests that it might also just make many of the infected (about half of the world's population!) neurotic, and this in turn might affect entire cultures:

...Lafferty wondered whether high rates of T. gondii infection in a culture could shift the average personality of its individuals.

"In populations where this parasite is very common, mass personality modification could result in cultural change," Lafferty said.

The distribution of T. gondii could explain differences in cultural aspects that relate to ego, money, material possessions, work and rules, Lafferty added. In some countries, infections by the cat parasite are very rare, while in others nearly all adults are infected.

To test his hypothesis, Lafferty looked at published data on cultural dimensions and average personalities for different countries. The countries examined also kept records of the prevalence of T. gondii antibodies in women of childbearing age. Countries with high prevalence of T. gondii infection also had higher average neuroticism scores.

"There could be a lot more to this story," Lafferty said. "Different responses to the parasite by men and women could lead to many additional cultural effects that are, as yet, difficult to analyze."

What I want to know is the rate of this infection in Muslim countries. Maybe the whole Middle East crisis is due to cats. (Just a theory.)

3 comments:

Anonymous said...

Wouldn't neuroticism reduce the risk of war. The article comments that humid midlatitude countries should in theory be worst affected - that doesn't sound like the middle east. Perhaps some neuroticism would help and we should be parachuting infected cats into the region.

Geoff

Steve said...

Yes, actually I thought that perhaps Jewish character could more likely be called neurotic than Muslims, but that would ruin my attempt to blame Muslims only. (And anyway, I am not 100% sure what neuroticism technically is considered to be.)

Anonymous said...

this might answer your questions
http://www.gnxp.com/blog/2006/08/toxoplasma-gondii-human-culture.php

The headline worthy aspect of T. gondii is that cats are a reservoir of this pathogen. But please note that warmer climate, high population density, working with soil and spoiled meats are also positively correlated with T. gondii infection. One interesting point that the author notes that T. gondii's affect on the sexes is inverted except for the trait of guilt, so it might be a wash if sexes are not separated in the analysis. From the paper, "...infected women, intelligence, superego strength (rule-conscious, dutiful, conscientious, conforming, moralistic, staid and rule-bound) and affectothymia (warm, outgoing, attentive to others, kindly, easy-going, participating and likes people) are higher, while infected men have lower intelligence, superego strength and novelty-seeking (low novelty-seeking indicates rigid, loyal, stoic, slow-tempered and frugal personalities); both infected men and women have higher levels of guilt-proneness (they tend to be more apprehensive, self-doubting, worried, guilt prone, insecure, worrying and self-blaming."


The author found a statistically significant correlation between neuroticism and T. gondii infection rates across nations. Variation in T. gondii infection explained about 1/3 of variation of neuroticism across countries. Other traits were so weak in their correlations (e.g., R2 of 0.07, or 7% of the variation) that they did not attain statistical significance. But, when the samples excluded non-Western nations other traits did attain statistical significance. Hungary and China had higher neuroticism than expected from T. gondii infection rates, while Turkey had lower neuroticism. Similarly, Japan and South Korea were dramatically more differentiated in sex roles than their low T. gondii rates would have predicted, while Jamaicans seemed to exhibit lower uncertainty avoidance. When only Western nations were considered uncertainty avoidance and masculine sex roles were signficantly predicated by T. gondii infection rates, with the later yielding an R2 of 0.27.