Diener, E., &Seligman, M. E. (2002). Very happy people. Psychological science, 13(1), 81-84.
A sample of 222 undergraduates was screened for high happiness using multiple confirming assessment filters. We compared the upper 10% of consistently very happy people with average and very unhappy people. The very happy people were highly social, and had stronger romantic and other social relationships than less happy groups. They were more extroverted, more agreeable, and less neurotic, and scored lower on several psychopathology ...