Research has documented that most men become much more jealous about sexual infidelity than they do about emotional infidelity. Women are the opposite. The prevailing theory is that the difference has evolutionary origins: Men learned over eons to be hyper-vigilant about sex because they can never be absolutely certain they are the father of a child, while women are much more concerned about having a partner who is committed to raising a family.

Scientists from the Université de Montréal are developing a weight loss pill composed of leptin, the protein that regulates appetite in mammals. The researchers say that leptin may be a good weight loss pill because its levels decrease when we fast and rise when we eat, meaning that increasing them could reduce people's urge to continue eating. The protein has also been proven to suppress appetite when administered intravenously to pathologically obese people.

"Taken orally, such a pill would provide obese people with the sensation of being full. They would eat less and in turn lose weight," says Dr. Cammisotto, one of the researchers on the project.