If happiness be one of the major goals of living, if not the only consciously acceptable end of life itself (most people in practice behave as though they were hedonists or eudaemonists), surely an analysis of the conditions fostering or hindering its attainment is an intellectual obligation of the first order, since upon it rests the merit of all other human and social values.

George Hartmann, ‘Personality Traits Associated with Variations in Happiness’, The Journal of Abnormal and Social Psychology, Vol, 29, No. 2 (July, 1934), p. 203