Complex sentence: Monahan (1941) studied social workers accustomed to interacting with people from all types of backgrounds, finding the majority found it very difficult to believe beautiful people are guilty of a crime.
Split into simpler sentences: Monahan (1941) did a study on social workers who are accustomed to interacting with people from all different types of backgrounds. The study found that the majority of these social workers found it very difficult to believe that beautiful looking people are guilty of a crime.