- Male college students, followed 3 years, Harvard University, USA, 1957-60
- N = 17
- Non Response:
- 37%: 9 dropouts, incomplete; about the same happiness distribution.
Mood diary kept 30 days and repeated interviews and tests during three years.
- Authors's label
- Hedonic level of most depressed moments
- Our Classification
- Repeated closed question on lowest mood experienced during the past day, rated on a 10-point scale during 6 weeks (Wessman & Ricks Elation-Depression Scale).