Adult Learning Theory

US psychologist Abraham Maslow's 1943 essay "A Theory of Human Motivation" established his idea of humanistic psychology as a "third force" in the field. He outlined a new approach to understanding the mind, saying humans are motivated by their need to satisfy a series of hierarchical needs, starting with the most essential first. He thought it important for the advancement of psychology to identify, group, and rank them in terms of priority.

Michael R. Gottfredson and Travis Hirschi's 1990 work, A General Theory of Crime, assessed contemporary work in criminology, while also introducing a new, comprehensive theory of crime. At the time, researchers tended to focus on environmental factors that led to crime, not on the criminals themselves. Additionally, crime researchers came from different disciplines and inclined towards thinking about crime only from their particular perspective. This meant ideas about what caused crime, and how to prevent it, were often in conflict.