A common parasite can increase a women's attractiveness to the opposite sex but also make men more stupid, an Australian researcher says. About 40 per cent of the world's population is infected with Toxoplasma gondii, including about eight million Australians. Human infection generally occurs when people eat raw or undercooked meat that has cysts containing the parasite, or accidentally ingest some of the parasite's eggs excreted by an infected cat. The parasite is known to be dangerous to pregnant women as it can cause disability or abortion of the unborn child, and can also kill people whose immune systems are...