Alcoholism was first viewed as a character disorder. In the middle of this century, it was considered a disease. Another example of how thinking has changed regarding human behaviors is homosexuality. It, too, has been considered a character disorder. Now there is some indication that genetics and biology underlie this orientation.
Autism is another phenomenon that was first thought to be due to a cold, uncaring mother.
Genetics is now thought to be the primary cause of autistic behavior. It can be seen, then, that theoretical views change as more scientific knowledge becomes available. We now know that all human development and behavior is influenced by both nature and nurture. Even when people live in the same environment, with the same influences, and the same parents, they turn out differently. That is because all individuals interact with their environments in unique, specific ways.