Cat Got Your Tongue?

I must be shot through with the stuff:

Kevin Lafferty is a smart, cautious, thoughtful scientist who doesn't hate cats, but he has put forth a provocative theory that suggests that a clever cat parasite may alter human cultures on a massive scale.

...The parasite, Toxoplasma gondii, has been transmitted indirectly from cats to roughly half the people on the planet, and it has been shown to affect human personalities in different ways.

Research has shown that women who are infected with the parasite tend to be warm, outgoing and attentive to others, while infected men tend to be less intelligent and probably a bit boring. But both men and women who are infected are more prone to feeling guilty and insecure.

Other researchers have linked the parasite to schizophrenia. In an adult, the symptoms are like a mild form of flu, but it can be much more serious in an infant or fetus. Oxford University researchers believe high levels of the parasite leads to hyperactivity and lower IQs in children.

...Building on research by scientists in the Czech Republic, Lafferty took a long look at areas of the globe where infection levels are quite high, or quite low. In Brazil, for example, two out of three women of child-bearing age are infected, whereas in the United States the number is only one out of eight.

Lafferty argues in a research paper published Aug. 2 in the Proceedings of the Royal Society, Biology, that aggregate personality types, or what cultures tend to be like, fit neatly with the effects that the parasite produces in individuals.

So that led to a basic question:

Can a common cat parasite account for part -- even if only a very small part -- of the cultural differences seen around the world?

...Toxoplasma, he notes, is "frighteningly amazing."

It can change the personality of a rat so much that the rat surrenders itself to a cat, just as the parasite wanted.

The parasite's eggs are shed in a cat's feces. A rat comes along, eats the feces, and becomes infected. The behavior of the rat undergoes a dramatic change, making the rat more adventuresome and more likely to hang out around cats.

The cat eats the rat, and the parasite completes its life cycle.

..."We have a parasite in our brain that is trying to get transmitted to a cat," he says. "This changes an individual's personality."

So if enough personalities are changed in a given society, will the culture of that society also be changed?

...Cat lovers need not get rid of their cats. The chances are not great that a modern cat, kept on a diet of safe cat food and not left to feed off rats, will transmit the parasite to humans. It's possible, but not likely, Lafferty says.

..."This isn't about trying to freak cat owners out," he says. "Simply having a cat as a pet doesn't mean you're going to get infected, for sure."

Of course, maybe some other parasite is making him say that.