How can differences in good and successful lives, defined in terms of life and work satisfaction, gross hourly wage, health and years of training, be explained? The results of inter-disciplinary research by economists and psychologists raise doubts as to whether economic preferences and social and economic environment are the only determining factors. The present study shows that inequality also results from the development of personality. Economic preferences and personality traits are not entirely interchangeable. Rather they are complementary characteristics. In all areas of life examined in the study, successful individuals in Germany manifest particularly high values for emotional stability and trust: 72 per cent of those who completely agreed with the statement "People are generally to be trusted” reported a high level of satisfaction with life, compared with only 52 per cent of all Germans.