The real question is “how many types of parasites ALREADY modify human behavior”.
We know toxoplasmosis does it, but how many have we not yet detected?
We know toxoplasmosis does it, but how many have we not yet detected?
Please bear in mind, I have no particular expertise about this issue, and so it's possible that my doubts here are not well founded.
https://academic.oup.com/schizophreniabulletin/article/33/3/...
The only valid conclusion here is that further study is needed.
Less interesting but still worth noting, many infections cause us to sneeze and cough in ways that increase the spread of the infection to others. Ain't evolution grand.
Another one, I remember that late stage Syphilis in at least some cases causes sexual promiscuity.