Much of what we now know about the influence of early childhood environments on delinquency and anti-social behavior can be traced to Bandura's ground-breaking 1973 book. He uses the subject of aggression to demonstrate the usefulness of social learning theory. Previous theories argued that behavior represented a simple, automatic response to environmental cues or that it was a result of subconscious drives. But Bandura suggests that humans are thinking, self-regulating beings with some influence over their environment arguing that aggression is a behavior that is learned and develops early in life. He also highlights the role of the media in generating and maintaining violence in society.