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The associations between prevalence and cultural dimensions are consistent with the prediction that T. gondii can influence human culture. Just as individuals infected with T. gondii score themselves higher in the neurotic factor guilt-proneness, nations with high T. gondii prevalence had a higher aggregate neuroticism score. In addition, Western nations with high T. gondii prevalence were higher in the ‘neurotic’ cultural dimensions of masculine sex roles and uncertainty avoidance. These results were predicted by a logical scaling-up from individuals to aggregate personalities to cultural dimensions.

Can the common brain parasite, Toxoplasma gondii, influence human culture?

Requiring that people have been incubated in a human womb seems like enough of a bottleneck

You're probably right. It probably is. But we lose nothing by being more conservative, because the first round of CEV will add in all the turkey baster babies.