Today we commemorate George A. Miller (3 Feb 1920 – 22 Jul 2012), an American psychologist, and one of the founders of modern cognitive psychology, and recipient of a National Medal of Science in 1991.
Miller contributed to the establishment of psycholinguistics as an independent research field in psychology. He studied the production and perception of speech, and later shifted his research focus to human memory.
He published a classic paper on memory recall (one of the most highly cited papers in psychology), entitled “The Magical Number Seven, Plus or Minus Two: Some Limits on our Capacity for Processing Information” (1956). The paper addresses the limits of human information processing and recall abilities.
Miller basically finds that the number of objects a person can recall in short term memory to be approximately 7. Similarly, in a ‘one-dimensional absolute-judgment task’, where a person is presented with a series of stimuli (different sound tones, for example) and has to respond to each stimulus with a pre-learned response, people can on average relate around 7 (plus or minus 2) stimulus-response pairs.
Since this article, many other cognitive numeric limits have been suggested, and these limits have been refined based on age, the complexity of the objects to be recalled, etc. Miller’s article, however, continues to be one of the most often referred to, and its reference to the ‘magical number seven’ have been used in various contexts, including the the argument that phone numbers should not exceed 7 digits, as this is the largest number people can comfortably remember. (This is one of the many examples where Millers results have been misappropriated, as the recall of phone numbers tend to be more of a long-term memory function, while Miller’s article referred to short-term (‘immediate’) memory.)
Based on his contributions to the field of cognitive psychology, Miller has been rated as one of the top 20 most eminent psychologists of the 20th century.