George A. Miller (1920-2012) was an American psychologist who became one of the central figures in the birth of cognitive science. Working at a time when behaviorism dominated psychology and treated the mind as a black box, Miller argued that human beings could be studied as information-processing systems with measurable limits on how much they can take in and remember at once. His best-known work, the 1956 paper “The Magical Number Seven, Plus or Minus Two,” is archived in full at the Classics in the History of Psychology collection hosted by York University.
The paper, published in Psychological Review (volume 63, pages 81 to 97), drew together experiments on how many distinct categories people can reliably judge along a single dimension - pitch, loudness, brightness - and found the limit clustered around seven. He separately observed that the span of immediate memory is also about seven items, though he was careful to note these are different mechanisms that happen to land on similar numbers. The deeper move was conceptual: Miller measured human capacity in bits, the unit Claude Shannon had introduced for information, and showed that the mind behaves like a limited-capacity channel.
In a 2003 retrospective in Trends in Cognitive Sciences, archived at Princeton, Miller dated the birth of cognitive science to a symposium at MIT in September 1956 where he, Noam Chomsky, and Allen Newell and Herbert Simon all presented within a day of each other. He left that meeting, he wrote, convinced that psychology, linguistics, and computer science were all asking the same questions about how minds work.
For business readers, Miller is a reminder that the modern idea of “information processing” - now so familiar it is invisible - was a hard-won reframing, and that the limits he measured still shape how people use the interfaces and tools that AI now powers.