Peter Cathcart Wason (22 April 1924 – 17 April 2003) was a cognitive psychologist at University College, London who pioneered the Psychology of Reasoning. He progressed explanations as to why people make certain consistent mistakes in logical reasoning. He designed problems and tests to demonstrate these processes, for example the Wason selection task, the THOG problem and the 2-4-6 problem. He also coined the term "confirmation bias" to describe the tendency for people to immediately favor information that validates their preconceptions, hypotheses and personal beliefs regardless of whether they are true or not. Personal life Wason was born in Bath Somerset on 22 April 1924, and died at seventy-nine in Wallingford, Oxfordshire on 17 April 2003. Peter Wason was the grandson to Eugene Wason, and the son to Eugene Monier and Kathleen (Woodhouse) Wason. Wason married Marjorie Vera Salberg in 1951, and the couple had two children, Armorer and Sarah. His uncle was Lieutenant General Sydney Rigby Wason. Peter Wason endured his schooling, which was marked by consistent failure. With the beginning of World War II, Wason completed officer training at Sandhurst, and then served as a liaison officer for the 8th Armoured Brigade, by then an independent brigade. Wason returned home in 1945, having been released from his duties of being an officer due to extreme injuries. Wason then pursued more academic ventures by studying English at Oxford in 1948, and continued on to become a lecturer at the University of Aberdeen. After the realization that he did not really prefer English, and actually found it quite boring, Wason returned to Oxford University to obtain a master's degree in psychology in 1953, and then a doctorate in 1956 from University College London. He remained teaching at University College London until his retirement in the early 1980s. Early studies Much of Peter Wason’s first areas of experimentation was not in the field of psychology of reasoning, but instead, language and psycholinguistics. Wason and Jones performed an experiment in which subjects were asked to evaluate numerical statements, such as “7 is even” and “9 is not odd”, and state whether the statement is true or false. The results revealed that affirmative assertions were evaluated faster as true than as false, but evaluation of negative assertions occurred faster as false than true. From these results, Wason came to the conclusion that negatives are used in daily lives and discourse to correct common