Several websites offer a free 16 personality types test, including 16personalities.com, humanmetrics.com and personality-testing.info. Several of the tests are based on the Myers-Briggs Type Indicator, a test developed on the personality theories of the psychologist Carl Gustag Jung. Other tests are based on the theories of British psychologist Raymond Cattell.
The personality inventory, known as the Myers-Briggs Type Indicator, was developed by a mother-daughter team, Katharine Briggs and Isabel Myers, during World War II to help with the integration of women into the wartime workforce. Raymond Cattell was involved in personality research during World War II, developing tests for the military to help with the selection of officers. This research, which he continued after the war, led to his creation of The Institute for Personality and Ability Testing (IPAT) in 1949.