He had a relatively turbulent to non-emotional, social, etc. dimensions of thought. Offered a job in a natural history museum even before he graduated high school. After, he left the field and studied psychology and philosophy at the sorbonne for family life that drew him towards psychoanalysis (or at least, psychology) 2 years to just understanding children"s development of thought. There, he met theodore simon, who worked on binet"s intelligence tests (iq) This was at last his great interest- how children"s thought developed. Used it as a means of understanding the origins of human thought, soon changed. Structures are unobservable mental systems that underlie intelligence. Children are motivated to learn by a need to satisfy their curiosity. Children build their own representations of reality; these change with child"s (st)age behind cognitive development. Adaptation to new information & mental reorganization are the driving forces. Broadly evolutionary idea, but more like development and embryonic development.