- 1914 – Lucy Ozarin, United States Navy lieutenant commander and psychiatrist (d. 2017).
- 1990 – B.F. Skinner, American psychologist and philosopher, invented the Skinner box (b. 1904).
Lucy Dorothy Ozarin (18 August 1914 to 17 September 2017) was a psychiatrist who served in the United States Navy.
She was one of the first women psychiatrists commissioned in the Navy, and she was one of seven female Navy psychiatrists who served during World War II.
Burrhus Frederic Skinner (20 March 1904 to 18 August 1990) was an American psychologist, behaviourist, author, inventor, and social philosopher. He was a professor of psychology at Harvard University from 1958 until his retirement in 1974.
Considering free will to be an illusion, Skinner saw human action as dependent on consequences of previous actions, a theory he would articulate as the principle of reinforcement: If the consequences to an action are bad, there is a high chance the action will not be repeated; if the consequences are good, the probability of the action being repeated becomes stronger.
Skinner developed behaviour analysis, especially the philosophy of radical behaviourism, and founded the experimental analysis of behaviour, a school of experimental research psychology. He also used operant conditioning to strengthen behaviour, considering the rate of response to be the most effective measure of response strength. To study operant conditioning, he invented the operant conditioning chamber (aka the Skinner box), and to measure rate he invented the cumulative recorder. Using these tools, he and Charles Ferster produced Skinner’s most influential experimental work, outlined in their 1957 book Schedules of Reinforcement.
Skinner was a prolific author, publishing 21 books and 180 articles. He imagined the application of his ideas to the design of a human community in his 1948 utopian novel, Walden Two, while his analysis of human behaviour culminated in his 1958 work, Verbal Behaviour.
Skinner, John B. Watson and Ivan Pavlov, are considered to be the pioneers of modern behaviourism. Accordingly, a June 2002 survey listed Skinner as the most influential psychologist of the 20th century.