From 1920s to 1960s american psychologists emphasized the study of

The answer for this question is: Observable behavior
Before this period, American psychologist was really fascinated with the study of the mental life. Because of the development in industrial technology, many companies started to put a lot of money in order to research observable behavior so they could expand their target market.

73637 is not the answer cuz i don’t know

Getting elected because not many people were voting