In a recent UCLA study , a variant in the oxytocin receptor gene has demonstrated different expressions of empathy and social skills. In their study, those with one type of variant were predisposed towards depression. Oxytocin is generally related to certain types of outgoing behavior, generousity, and is also known as the "cuddling gene" (from orginal tests that oxytocin made rats cuddle). The study sheds light on an issue that certain people may not have the same fundemental psychological tools to cope with stress and other life challenges, leaving them predisposed and tending toward symptoms of depression. It's important to note that, according to this study: nobody is doomed to fail. It just means that you have to stimulate your own production of oxytocin. In a study at SUNY Stoney Brook , scientists were able to link dopamine and oxytocin production to people who had a real goal (specifically: this study was about "falling in love"). The production of th...