The Regents of the University express their deep sorrow at the loss of Klaus F. Riegel, Professor of Psychology, who died Sunday, July 3, at the age of 51.

Professor Riegel will be remembered by his many students as a kind, patient, and generous teacher, always willing to listen and to encourage. His colleagues will recall his unrelenting energy in contributing to the growth of developmental psychology, and in motivating others with his enthusiasm and insights.

Professor Riegel joined the faculty of the Psychology Department at the University in 1959. After earning his M.A. at the University of Minnesota in 1955 and his Ph.D. at the University of Hamburg in 1958, he spent a postdoctoral year as a Visiting Scientist at the National Institute of Health. He was a participant in the University's Psycholinguistics Program, the Institute of Gerontology, and its Center for Human Growth and Development. He was the author or editor of many books and a regular contributor to the journal literature in his several areas of interest including the development and assessment of intellectual functions of the aged, psycholinguistics, and the history and philosophy of the social sciences.

A member of many professional organizations, Professor Riegel was elected as a fellow in both the Gerontological Society and the American Psychological Association. He also served on the Executive Committee of the International Society for the Study of Behavioral Development, and as president of the Psychological and Social Sciences Section of the Gerontological Society. In 1976, the Gerontological Society recognized Professor Riegel's contributions by presenting him with the Robert W. Kleemeier Award. He also contributed greatly to the growth and increasing eminence of the international journal, Human Development, as its editor from 1970 onward.

In recent years, Professor Riegel labored unceasingly towards the formulation of a dialectical psychology, through his own writing and lecturing and also through annual conferences held successively at Rochester, Toronto, Cape Cod, and in 1977, at Shimer College. Dialectical Psychology, as he perceived it, focuses upon the understanding of activities and changes rather than static traits and balanced equilibria, and recognizes the necessary interdependence of developmental changes in the individual with historical changes in the larger society. His conceptualization is an unusual and a significant one for psychology, and thus will describe a history of interpretations in psychology appropriate to the succession of historical changes in the society. Thus, Professor Riegel's work has set psychology on a new and unpredictable course, by helping it to become conscious of our own development as a discipline.

The premature death of Professor Riegel is a great loss to the discipline and to the University. His many and devoted students and colleagues will honor him by carrying forward his work and responding to his stimulating challenges.

The Regents join the entire University community in mourning his death and extend deepest sympathies to his family.