There are a number of things that contribute to our overall happiness (1) biology (2) thinking style (3) learned behaviour. While there is a genetic set point for happiness, positive psychology tells us that we can in fact learn to be happy. Those without the happy genes can actually learn to have a more optimistic outlook on life. The good news from the research is that we can change how we think and learn new behaviours so that we can be cheerful!
Psychologists have now come up with a formula for happiness. It is: Pleasure + engagement + meaning = happiness.