Alan David Baddeley FRS, CBE (born 1934) is a British psychologist. He is professor of psychology at the University of York. He is known for his work on working memory, in particular for his multiple components model.
Baddeley graduated from University College London in 1956 and obtained an M.A. from Princeton University's Department of Psychology in 1957. He then embarked upon a research on the psychology of insects, but his limited prowess for woodlouse husbandry led his studies serendipitously into a career upon human cognitive psychology. He was awarded with a Ph.D. from University of Cambridge in 1962. He was awarded an Honorary Doctorate by Essex University in 1999.
Working with Graham Hitch, Baddeley developed an influential model of working memory called Baddeley's model of working memory, which argues for the existence of multiple short term memory stores and a separate interacting system for manipulating the content of these stores. The model accounts for much of the empirical data on short-term retention and manipulation of information.
His landmark study in 1975 on 'Capacity of Short Term Memory' showed that people remembered more short words than long words in a recall test. This was called the word length effect and it demonstrated that pronunciation time rather that number of items determines the capacity of verbal short term memory.
He was elected a Fellow of the Royal Society in 1993. In 1996, he was elected a Foreign Honorary Member of the American Academy of Arts and Sciences.