Etiology. There are many possible psychological theories that can explain Sal’s symptoms. For example, a psychodynamic argument may be that his general mental abnormalities stem from the death of his mother. A behaviorist may believe that a learned reward system explains why Sal is so withdrawn or why he has mysterious, unexplained pains. Cognitively, Sal may not be an accurate judge of reality and how his actions negatively affect himself or others. I believe one of the biggest explanations can be found in the family systems theory, which states that the structure and workings of the family unit influence some members of that family to behave abnormally (Comer 2005). The arrival of a stepmother may have caused some disruption in normal family life, and the ways in which both she and Sal’s father respond (or do not respond) to Sal can perpetuate his abnormalities, even into young adulthood.