It all began with a question from students: which psychological theory is right, if they contradict each other? Instead of choosing one, Graves started his own research. He asked students to describe what a psychologically mature, healthy adult is like, and then they discussed and critiqued each other’s descriptions.
From 1952 to 1959 he collected answers from about 1065 people aged 18 to 61, and kept adding to them for another twelve years. The answers didn’t boil down to one “right” picture. They formed a series of levels, and each new one grew out of the previous one when life conditions changed. Graves called this the theory of levels of existence and was convinced that development has no end point.







