Evaluation of Authoritarian Personality Theory
The problem with using an attitude scale such as the Likert scale for testing people's personality is that a person who has a strong desire to please may give false results without realising it. So it is not possible to categorically claim that a high score on the F scale identifies an authoritarian personality. Other measures such as observation and interviews would be necessary to identify actual behaviours related to the personality type. (This criticism is true of all trait type personality tests)
Brown (1988) pointed out that the claim that certain personality types are authoritarian does not explain why whole groups and even populations of people can display prejudice, especially at particular times in history e.g. the German attitude towards the Jews around the time of WWII.
Attitudes towards other groups can change according to social and political events and changes in group thinking. An example of this is that commonly held racist ideas in the South of the USA for instance have changed over time. In the 1950s and 60s, racist attitudes were neither frowned upon nor unusual. In the 21st Century they are both illegal and socially unacceptable.