Happiness is used in the context of mental or emotional states, including positive or pleasant emotions ranging from contentment to intense joy. It is also used in the context of life satisfaction, subjective well-being, eudaimonia, flourishing and well-being.
Since the 1960s, happiness research has been conducted in a wide variety of scientific disciplines, including gerontology, social psychology, clinical and medical research and happiness economics.
Despite a greatly increased standard of living, people in the USA reporting that they were "very happy" were no more numerous in 1991 than in 1957. Professions with the highest proportion of unhappy people were doctors and lawyers (who are also in the highest income groups in the USA).