Researchers found that when southerners joined the armed forces and were exposed to less prejudiced norms, they gradually grew less prejudiced themselves. both of these studied demonstrate one way to study the power of normative pressures: track prejudice and discrimination over time. the studies find that as change,

The answers to the given blanks above are NORMS, and CONFORMITY PRESSURES CHANGE ATTITUDES, respectively.
This research is actually based from Jean Watson (1950), an American nurse theorist who is known for her theory of Human Caring. According to her, when the given standards in an environment are changed, this also affects how a person deals with the people around his or her environment. Given above that there is lesser prejudice, this also changed their attitude by being less prejudiced.