Parasite May Affect Cultural Traits

We may not like the idea, but there is a logic to it: it could be that this parasite does affect the brain chemistry of hosts to increase its chances of being able to pass to its preferred host by making risky behaviours more likely.

Toxoplasma is associated with different, often opposite, behavioral changes in men and women, but both genders exhibit guilt proneness (a form of neuroticism). Lafferty's analysis found that countries with high Toxoplasma prevalence had a higher aggregate neuroticism score, and western nations with high prevalence also scored higher in the 'neurotic' cultural dimensions of 'masculine' sex roles and uncertainty avoidance.

I'm doubly interested in the guilt prone-ness thing and wonder whether a medieval preoccupation with guilt and guilt management could have had some biological drivers. And the mirror of this of whether a loss of preoccupation with guilt in our culture may have some roots in greater hygiene ... more information needed, but it's an intriguing possibility. Note that I'm not saying anything about the objectivity of guilt, just the prone-ness to feeling it.
ScienceDaily: Cat Parasite May Affect Cultural Traits In Human Populations
Filed in: toxoplasmosis, culture, personality, aggregation