Answer:
Relative deprivation principle.
Step-by-step explanation:
World war II was a war that started on the 1st day of the month of September, in the year 1939 and it ended on the 2nd day of September, in the year 1945.
During the world war II the military branch were not happy because the rate at which the U.S. Air Corps were been promoted is higher than them. So, Sociologists and Psychologist used a theory to explain the attitude of the military branch and the theory is known as the RELATIVE DEPRIVATION PRINCIPLE.
The Relative deprivation principle is the principle that explains people's attitude when they are not given what they deserve for instance these set of deprived people might form a movement to fight for their rights in the society.