1. Kjell Å. Salvesen is a research scientist in the Department of Community Medicine and Family Practice, University of Trondheim, Norway. He works in the fields of epidemiology and obstetrical ultrasonography. He received his medical degree from the University of Trondheim.
2. Johan O. Undheim is professor of psychology in the Department of Psychology, AVH, University of Trondheim, Norway. He works in both cognitive psychology and psychometry. His research interests focus on human intellectual abilities and on multivariate analysis of individual differences. Professor Undheim is currently head of the department. Address: Kjell $AR. Salvesen, Department of Community Medicine and Family Practice, University Medical Center, N-7005 Trondheim, Norway.