Insight learning is the sudden reorganization of a problem's elements leading to the perception of a solution, often experienced as an "Aha!" moment. Unlike the gradual, incremental learning described by behaviorists, insight appears to occur all at once, often after a period of apparent impasse. Wolfgang Kohler's observations of chimpanzees solving problems (reaching bananas by stacking boxes or joining sticks) provided classic demonstrations of insight learning in animals.
Kohler's Experiments
Kohler (1925) placed chimpanzees in situations where food was out of reach but tools (sticks, boxes) were available. After periods of apparent frustration and inactivity, chimpanzees would suddenly produce the correct solution — stacking boxes to reach high-hanging bananas or connecting two short sticks to make one long enough to reach food outside the cage. The solutions appeared suddenly and were immediately performed smoothly, suggesting a cognitive reorganization of the problem rather than trial-and-error learning.
Insight problem solving has several distinctive features: a period of impasse during which standard approaches fail; a sudden restructuring of the problem representation; a clear "Aha!" feeling of understanding; and the ability to immediately execute the solution correctly once it is perceived. These features distinguish insight from incremental problem solving and suggest that different cognitive and neural mechanisms may be involved — a view supported by neuroimaging evidence showing distinct brain activation patterns during insight solutions.
Neural Correlates
Mark Jung-Beeman and colleagues have identified neural signatures of insight using EEG and fMRI. Solutions achieved through insight are accompanied by a burst of gamma-band neural activity in the right anterior temporal lobe, approximately 300 ms before the conscious "Aha!" experience. This burst is preceded by increased alpha activity over right posterior regions, possibly reflecting the internal focus of attention that precedes restructuring. These findings suggest that insight involves the sudden integration of distantly related information in the right hemisphere.
Modern Research
Contemporary insight research uses carefully designed problems that require restructuring to solve. Classic examples include the nine-dot problem (connecting nine dots with four straight lines without lifting the pen), the two-string problem (joining strings too far apart to reach both simultaneously), and matchstick arithmetic problems (rearranging matchsticks to correct equations). Research continues to investigate what triggers the representational change that enables insight, including the roles of incubation, attention, mood, and sleep.