Philosophers and religious thinkers often define happiness in terms of living a good life, or flourishing, rather than simply as an emotion. Happiness in this sense was used to translate the Greek Eudaimonia, and is still used in virtue ethics. Happiness economics suggests that measures of public happiness should be used to supplement more traditional economic measures when evaluating the success of public policy.
Happiness is a fuzzy concept and can mean many different things to many people. Part of the challenge of a science of happiness is to identify different concepts of happiness, and where applicable, split them into their components. Related concepts are well-being, quality of life and flourishing. Some commentators focus on the difference between the hedonistic tradition of seeking pleasant and avoiding unpleasant experiences, and the eudaimonic tradition of living life in a full and deeply satisfying way.
The 2012 World Happiness Report stated that in subjective well-being measures, the primary distinction is between cognitive life evaluations and emotional reports. . Happiness is used in both life evaluation, as in “How happy are you with your life as a whole?”, and in emotional reports, as in “How happy are you now?,” and people seem able to use happiness as appropriate in these verbal contexts.
Research has produced many different views on causes of happiness, and on factors that correlate with happiness, but no validated method has been found to substantially improve long-term happiness in a meaningful way for most people.
Sonja Lyubomirsky concludes in her book The How of Happiness that 50 percent of a given human's happiness level is genetically determined, 10 percent is affected by life circumstances and situation, and a remaining 40 percent of happiness is subject to self-control.
The results of the 75 year Grant study of Harvard undergraduates show a high correlation of loving relationship, especially with parents, with later life wellbeing.
In the 2nd Edition of the Handbook of Emotions, evolutionary psychologists Leda Cosmides and John Tooby say that happiness comes from "encountering unexpected positive events". In the 3rd Edition of the Handbook of Emotions, Michael Lewis says "happiness can be elicited by seeing a significant other". According to Mark Leary, as reported in a November 1995 issue of Psychology Today, "we are happiest when basking in the acceptance and praise of others". Sara Algoe and Jonathan Haidt say that "happiness" may be the label for a family of related emotional states, such as joy, amusement, satisfaction, gratification, euphoria, and triumph.
It has been argued that money cannot effectively "buy" much happiness unless it is used in certain ways. "Beyond the point at which people have enough to comfortably feed, clothe, and house themselves, having more money - even a lot more money - makes them only a little bit happier." A Harvard Business School study found that "spending money on others actually makes us happier than spending it on ourselves".
Meditation has been found to lead to high activity in the brain's left prefrontal cortex, which in turn has been found to correlate with happiness.
Psychologist Martin Seligman asserts that happiness is not solely derived from external, momentary