Want to make a special someone purr? Maybe you should give her a cat.
A study has shown that domestic cats infected with a parasite called toxoplasma gondii (search) can actually alter the personalities of their human owners, turning women into “sex kittens" and men into “alley cats.”
“We found they [the infected women] were more easygoing, more warm-hearted, had more friends and cared more about how they looked. However, they were also less trustworthy and had more relationships with men,” Dr. Jaroslav Flegr, who conducted the study at Charles University in Prague, told London’s Sunday Times newspaper.
Infected men, on the other hand, became more aggressive, less well-groomed, undesirable loners who were more likely to be suspicious and jealous.
“They tended to dislike following rules,” Flegr told the Times.
In the study, funded by the Stanley Research Medical Institute (search) in Bethesda, Md., Flegr subjected more than 300 volunteers to personality profiling while testing them for toxoplasma, a parasite long known to be dangerous to unborn babies.
Moms-to-be are urged to avoid the litter box and the garden when they are pregnant, as toxoplasma is passed through cat feces.
According to Flegr's findings, infected women spent more money on clothes and were consistently rated as more attractive. By contrast, infected men became less attractive and more anti-social.
But kitty lovers were catty about the study.
Psychology student Todd Kray, 42, said there’s no way this — or almost anything else — could make him give up Edison, his cat of 10 years.
“Cats mythologically represent evil spirits, are thought to carry disease — my grandma was scared witless of cats. So it’s probably more of the same-old," he said.
He also said he thinks his attractiveness is "OK" and that he is more well-groomed than he was in the past.
Dr. Stephen Waring, a Texas veterinarian who studies the passage of diseases from animals to humans, wondered if the findings were a joke.
“You would have to do some pretty serious tests to find out if a person has been exposed to toxoplasma. And if the antibody is there it means you were exposed to it, but in most healthy people it will have no effect," he said, adding that the correlation between the personality changes and the infection could be a coincidence.
Nevertheless, Waring didn't rule out the feline phenomenon.
"It's possible," he said. "We now have the genetic and molecular technology to look far back and say this may have caused a change in the brain and set something in motion that later manifested as a behavior problem."
Dr. Thomas Boll, director of the Neuropsychology Institute in Birmingham, Ala., said there seems to be a missing link between the infection and the behavior change.
"You'd have to document how the infection produces a change in brain function. And you don't get personality change from infection. Personality only comes from the brain."
In separate research, the Stanley Research Medical Institute also found evidence that people with mental illnesses like schizophrenia (search) have increased antibodies to toxoplasma, signifying exposure to the parasite. But the study is not 100 percent conclusive.
“There is some clear evidence that people with schizophrenia have increased antibodies to toxoplasma," said E. Fuller Torrey, a research psychologist with the institute. "But about 30 to 40 percent of us have antibodies to toxoplasma. This is a common infection — why would it cause mental illness in some but not others? We have to sort through that."
It has long been known that cats are able to infect people with toxoplasma, but the parasite has been thought harmful only to pregnant women and people with compromised immune systems.
Outdoor cats that interact with other animals are particularly susceptible to the infection, but can, like humans, be checked for it and treated with medications if necessary.
Clea Simon, author of "The Feline Mystique," said cats do have an effect on people's personalities, but this probably has nothing to do with any parasite.
"In some ways cats can and do teach women to be more independent and more desirable," she said. "And maybe cats’ independence also teaches men to think for themselves, to become more free-spirited."