Oh noes, you have a reason...

And the reason is TOXOPLASMOSIS (everybody panic!)

....this 1996 paper which showed than men who were infected were more likely to disregard rules, were less trusting and tolerant, and more jealous, reserved, critical, detached, and guilt prone. Infected women, on the other hand, were more "warmhearted," outgoing, easygoing, trusting, accepting, tolerant, astute, worldly, and polished. In other words, the effects on men and women were in entirely opposite directions. Even more disturbing was the 2003 paper reporting research using military personell that showed infected men to be more impulsive, extravagant, and disorderly (they looked more ragged), along with having lower IQs, lower education levels, and lower levels of novelty seeking....

[via Mixing Memory]