Probably not much at all. Toxoplasmosis wouldn't explain a sex-biased result. Additionally there's no good evidence that the parasite affects human cognition.

Probably not much at all. Toxoplasmosis wouldn't explain a sex-biased result. Additionally there's no good evidence that the parasite affects human cognition. Something much more simple is likely going on. In all likelihood cats are more like brood parasites (http://en.wikipedia.org/wiki/Brood_parasite http://en.wikipedia.org/wiki/Brood_parasite). They're about the same size as a human infant, have faces with juvenile features (i.e. are "cute") and mine wakes me up at 2 hour intervals at night asking for food. Basically they're furry babies.