Joe Tsao

Toxoplasmosis, a parasitic disease that infects the brain, normally infects cats (but can infect many other warm-blooded animals as well, including humans). About 1/3 of the people in the world are infected, and the CDC estimates that 1/10 of the American population are infected. But don’t worry – normally toxo infections are as harmless to humans as Charmander’s flame attacks are to Squirtle.

The infection is caused by the parasite Toxoplasma gondii. This disease is highly prevalent in rats, and therefore highly prevalent in cats as well. Scientists at Oxford University have found that although normal rats tend to avoid areas with cat scents, those infected by toxo actually are attracted to cat scents, making them the brave! The adventurous! The dead. This makes sense in evolution. By making infected rats more likely to be eaten by cats, Toxo makes itself more easily spread. (In humans, it can be spread through contact with cats or though eating infected raw meat).

Well cue this article by Slate. According to Slate, prevalence of Toxo infection strangely is able to predict winners of elimination matches. In fact, 15 out of the last 16 winners of the first knockout game over the last two world cups were from countries with higher infection rates of Toxo! The article tries to tie infection with behavior, stating that it is know that Toxo increases testosterone in male brains, making them more likely to engage in risky behavior. They have more “aggressive and less inhibited.”

(Image taken from the Slate.com article. Without permission. I hope this is OK)

A report released by Schizophrenia Bulletin, Effects of Toxoplasma on Human Behavior, by Jasroslav Flegr, does find differences in human behavior between those infected and those uninfected. Those infected were found to be more vigilent, likely to “disregard rules and [to be] more expedient, suspicious, jealous, and dogmatic.” They were more likely to have been in traffic accidents, with lower reaction times.

So could infection with parasites make a more ruthless, more fearless sports star? Well, has anyone seen Ron Artest?

This entry was posted on Friday, July 2nd, 2010 at 4:46 pm and is filed under Medicine. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.