Czech scientist: feeling depressed, withdrawn? Blame your cat
Now, have you been feeling a bit strange lately? Men - have you been feeling jealous, withdrawn, depressed? Women - have you been feeling unusually outgoing, flirtatious even? Well, if you have noticed some sudden changes in your behaviour, there's a good chance you've been infected with a parasite called toxoplasma - and believe it or not, you probably caught it from your cat. No, we haven't gone completely mad: Jaroslav Flegr, a scientist at Prague's Charles University, claims that millions of people around the world are infected with the primarily cat-borne toxoplasma parasite, and their behaviour has changed as a result. So what - exactly - is the toxoplasma bug?
Thirty percent of the world's population carry the toxoplasma parasite?
"It varies from country to country. In some countries it's 60 percent, even 90 percent. But as far as I know, in the Czech Republic, in the USA, it's around 30 percent."
You've done some very interesting research that suggests the toxoplasma parasite in humans can affect people's behaviour. Tell me more about that.
"Well at first we recognised that it can influence psychological profiles. So when infected subjects filled out psychological questionnaires, we obtained different results than from uninfected subjects. Then later we started also to study behaviour, and we found out that even the behaviour of infected humans is different."
In what way? How does that behaviour differ?
"Infected humans are slower, in general. Also, for example, women are more outgoing, easy-going. And what's interesting is that for men, it's quite the opposite."
So you say people infected with toxoplasmosis, their whole personality changes to some extent - women become more outgoing, more friendly, men become more withdrawn, depressed. But surely these claims could just be an accident of statistics couldn't they? It could be just coincidence.
"Yes, and statistics can also tell us the probability of such a coincidence, and in fact it's pretty low."
What next? You've alerted people to the danger of this parasite and the way it can affect human behaviour. Can this information be used in some way to eradicate the parasite, or is that impossible?
"I think it's very difficult to eradicate this parasite. But maybe scientists should try and find a vaccine for cats. The cat is the only definitive host. In islands where there are no cats, there is no toxoplasmosis."
