Can someone please help me answer these question please thank you

In 1957, james vicary reported that subliminal messages in a movie reel ("eat popcorn") caused viewers to rush to the concessions stands. although his findings became famous, the problem is that

Apsychologist has developed a series of personality inventories and wants to determine if they are valid. one of the scales measures perfectionism, so he asks a colleague for advice on how to establish the validity of this scale. the colleague tells him that if he were to find a sample of people with personality disorder, these people would obtain high scores on a scale that measures perfectionism.

What was the main motivation for the early populists