Wolfgang Kohler

German-American psychologist and Gestalt school co-founder who demonstrated insight learning in chimpanzees and developed the concept of isomorphism — the structural correspondence between brain processes and conscious experience.

Showed through experiments with chimpanzees that problem-solving can occur through sudden perceptual reorganization (insight) rather than incremental trial-and-error — providing biological grounding for the Gestalt principle that wholes are primary in mental life.