Science is proving what most of us already know: Some people are more likely to see the glass as half-full than others. Turns out the reason why some of us are more optimistic than others is held deep in our genes. Published online in the Proceedings of the National Academy of Sciences, scientists have honed in a small piece of genetic material that may control feelings of optimism, self-esteem and the belief that you have control over your own life and destiny.
The genetic material is linked to the hormone oxytocin, known more often as the cuddle hormone, which is released in breastfeeding women, and when both men and women orgasm. (This is why cuddling after sex always feels so darn good.)
Although researchers don't fully understand how the gene affects the release of oxytocin, people studied with a particular gene variation were found to have less optimism, mastery and self-esteem, and more symptoms of depression than other subjects with a different variation.
However, researchers are quick to point out that when it comes to genes and human behavior, things are much more complex. Genes may predict behavior, but environment and your own personal experience can greatly change how your genes influence you.