My teacher heaped on me for my research project about the civil rights movement. preys praise praize prays

I believe answer is: Praise

Preys mean something or someone that being hunted by others, praize does not have specific meaning, while prays refers to the act of communicating with a certain type of diety.

Praise means the act of expressing admiration toward a certain things, which is the most suitable for the sentence above.

answer; decipher the motives for why people behave the way they do;