Here is an article that explains why some of us engage in dangerous behavior, the tantalizing evidence that toxoplasmosis, a common parasite, may affect human behavior. The article is entitled A game of cat and mouse and postulates that “…entire societies are being altered by Toxoplasma. In 2006 Kevin Lafferty of the University of California, Santa Barbara, published a paper noting a correlation between levels of neuroticism established by national surveys in various countries and the level of Toxoplasma infection recorded in pregnant women… phlegmatic Britain, with a neuroticism score of -0.8 and a Toxoplasma infection rate of 6.6%, to hot-blooded France, which scored 1.8 and had an infection rate of 45%…”