[_tom_]

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?

[everdrive]

With toxoplasmosis in particular, people cite that old study over and over. I always wonder to what degree that's been replicated, or to what degree the study's claims have been exaggerated because of their controversial nature.

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.

[matheusmoreira]

This paper, right?

https://academic.oup.com/schizophreniabulletin/article/33/3/...

The only valid conclusion here is that further study is needed.

[kadoban]

We know our gut biome in general has a huge effect on our behavior as well (most obviously around food choices), though I don't think those are technically "parasites".

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.

[joaomacp]

I've also read that the cold or flu virus makes us seek more human contact and feel more affectionate, supposedly overriding our mind in order to propagate the virus.

[geoduck14]

That explains a lot of bad decisions with the Corona Virus