Zimmer: Return of the puppet masters

Carl Zimmer of Corante has written a piece about mind viruses. No, not memes -- real, biological parasites that may be altering emotional subjectivity in humans.

Specifically, Zimmer is referring to Toxoplasma gondii, a single-celled parasite that lives in the stomachs of cats, sheddding eggs that can be picked up by rats and other animals that can just so happen be eaten by cats. This parasite forms cysts throughout its intermediate host's body, including the brain.

What's scary, however, is what it does to the host's brain: scientists believe that Toxoplasma changes the personality of its human hosts, bringing different shifts to men and women.

Parasitologist Jaroslav Flegr of Charles University in Prague administered psychological questionnaires to people infected with Toxoplasma and controls. Those infected, writes Zimmer, show a small, but statistically significant, tendency to be more self-reproaching and insecure. Paradoxically, infected women, on average, tend to be more outgoing and warmhearted than controls, while infected men tend to be more jealous and suspicious.

Yikes.

As Zimmer notes, it's disturbing to think that parasites are tinkering with humanity's personality -- perhaps even giving rise to cultural and sexual diversity.

Tags: neuroscience, philosophy of mind, consciousness, toxoplasma gondii, parasites