A report recently published in The Proceedings of the Royal Society "Biology" by a researcher suggest that a parasite spread by cats to about half of the earth's population, called toxoplasma gondii, may be responsible for changes in personality.
It is claimed that women become more outgoing and warm, men less intelligent and boring, and both sexes less secure about themselves. Children may experience hyperactivity and lower IQs. Previous research on the parasite made similar discoveries.
Rats infected with the parasite tended to hang out more around cats. Many parasites apparently use the tactic in order to attract a new host, who will eventually spread their eggs through droppings.