Bärbel Inhelder

Bärbel Inhelder (1913 to 1997) was a Swiss psychologist, born in St. Gallen, who worked at the University of Geneva for her whole career and is best known for her fifty year collaboration with Jean Piaget on child development. Her doctoral work on children's understanding of conservation led to her first publication, and her experiments with Piaget helped identify the formal operational stage that appears in the transition from childhood to adolescence. Together they published The Growth of Logical Thinking from Childhood to Adolescence, The Psychology of the Child and The Child's Conception of Space. A visiting appointment at Harvard in 1961 and 1962 pushed her toward a more functional approach, and in 1976 she was elected a Foreign Honorary Member of the American Academy of Arts and Sciences.