According to this article, researchers determined that a certain combination of genes provides some people with what they call an “affective reserve,” which allows them to be happy even in the face of circumstances that cause others to be unhappy. However, the article seems to simply confirm what others have been saying already - happiness (or depression) is a 50%-50% proposition. That is, 50% genes, and 50% environment. The important points I take from studies like this are: 1) 50% of the stuff that impacts one’s happiness or unhappiness is unrelated to one’s genetic make-up, which means it is alterable, and 2) some people simply have to work harder than others to be happy, but that doesn’t mean they can’t be happy. It may not be fair, but if you know that’s the way it is, you then have a choice, rather than being locked in to a life of less happiness than you might otherwise have.