"Wallach, Hans"@en . . "1998Z"^^ . "1998-02-05Z"^^ . "American psychologist" . "1904-11-28Z"^^ . "1904Z"^^ . "Hans Wallach (November 28, 1904 \u2013 February 5, 1998) was a German-American experimental psychologist whose research focused on perception and learning. Although he was trained in the Gestalt psychology tradition, much of his later work explored the adaptability of perceptual systems based on the perceiver\u2019s experience, whereas most Gestalt theorists emphasized inherent qualities of stimuli and downplayed the role of experience."@en . .