Sonja Lyubomirsky, of the University of California- Riverside, says the greatest predictor of happiness is the existence of intimate relationships. Answering yes to either question means the person's whole life is likely to be happy. A good attitude sure doesn't hurt. Edward Diener, of the University of Illinois identified four traits associated with being happy. Happy people like themselves.
Happy people feel in control of their lives.
Happy people are optimistic. Happy people tend to be extroverts. It's just like your mother told you.