Joan Mowat Erikson, an authority on human development, died Aug. 3 at Brewster Manor Nursing Home in Brewster. She was 95.

Erikson was the widow of Professor of Human Development Emeritus Erik H. Erikson. The pair popularized a theory known as the Eriksonian life cycle. The theory says that one's sense of identity progresses through eight distinct life cycles marked by the resolution of successive emotional conflicts.

Erikson was born in Toronto and graduated from Barnard College.

Erikson was the author of several books, including The Universal Bead; Activity, Recovery, and Growth; and Wisdom and the Senses.

The Eriksons lived in a multi-generational household in Cambridge.

She leaves two sons, Kai of Hamden, Conn., and Jon of Port Angeles, Wash.; a daughter, Sue Bloland of New York City; and three grandchildren.