US psychologist Abraham Maslow’s A Theory of Human Motivation is a classic of psychological research that helped change the field for good. Like many field-changing thinkers, Maslow was not just a talented researcher, he was also a creative thinker - able to see things from a new perspective and show them in a different light. He studied what he called exemplary people such as Albert Einstein, Jane Addams, Eleanor Roosevelt, and Frederick Douglass rather than mentally ill or neurotic people.