An anonymous reader writes "For reasons that scientists have not conclusively determined, women are happier than men. And now, researchers think that they may have pinpointed one of the reasons for that. They have found a gene in women that predicts the level of happiness in women. 'After controlling for various factors, ranging from age and education to income, the researchers found that women with the low-expression type of MAOA were significantly happier than others. Compared to women with no copies of the low-expression version of the MAOA gene, women with one copy scored higher on the happiness scale and those with two copies increased their score even more. While a substantial number of men carried a copy of the "happy" version of the MAOA gene, they reported no more happiness than those without it.'"