John Hurley Flavell (born August 9, 1928, in Rockland, Massachusetts) is an American developmental psychologist specializing in children's cognitive development who serves as Anne T. and Robert M. Bass Professor, Emeritus at Stanford University.
[5] After graduating from high school in 1945, Flavell joined the United States Army until 1947, reaching the rank of private first class.
Flavell and his colleagues have found that whereas most three-year-olds fail these tasks, five-year-olds and older four-year-olds succeed on them.
The appearance–reality paradigm, along with the false-belief task, is widely used as diagnostic of theory of mind development during early childhood.
Flavell's other work has addressed children's developing understanding of perception, perspective-taking, and their introspective insight into their own subjective experiences.