What Maslow did that differed so radically from psychologists before him was suggest that there was as much importance in positive mental health as examining the psychopathic natures. He felt that a person's potential could be probed as well as their deficiencies, leading to further understanding of human nature.
Maslow's studies culminated in his development of what is called The Hierarchy of Needs in his 1943 paper, "A Theory of Human Motivation". Often displayed as a pyramid, Maslow purported that if the lower rungs, or blocks, were not tended to then a person would not be able to move up to the higher. The lower blocks are known as 'deficiency needs' as being deprived of one would overrule all else; needs such as water, air, food, and sleep. The higher were 'growth' or 'being needs': security, safety, belonging love, self-esteem, accomplishment, and, finally, self-actualization.
Self-actualization was another term that Maslow coined. He referred to those people who were self-actualizers are those capable of sensing and achieving their full potential: creative, spontaneous, and hard-working people not bound by society's limiting perspective. They are able to be honest and make judgments based on their own decisions.
This self-awareness could lead to 'peak experiences'. Maslow defined peak experiences as an enhanced feeling of being alive and connected to the world. Peak experiences could even manifest a step further, as coming out of oneself and engaging in the fullness of being part of something greater. In his 1971 piece, Maslow called it "feelings of limitless horizons opening up to the vision, the feeling of being."
The humanistic approach emerged in the 1950s and 60s, with Maslow at its head. It gave birth to a therapy more focused on a person's capability for growth and sought to explore what had to be removed to help that person advance. Maslow's theories also went on to expand thinking in the areas of religion and business. Shostrom's Personal Orientation Inventory grew out of Maslow's self-actualization.
He theorized the third branch of 'transpersonal psychology'. To Maslow, the previous studies of behaviorism and psychopathy were too limited, unable to account for the higher attributes of human nature - such as values and love. Transpersonal sought to fulfill an entire spectrum of human behavior, and beyond.
Maslow didn't spend hours upon hours in massive research projects, so much as ask questions that previous psychologists had not. His focus on the positive growth of the human psyche rather than its decay allowed for new schools of thinking and research. His hierarchy of needs, self-actualization, transpersonal psychology, and humanistic approach enabled much of psychology today, and continues to grow.
Learn more with further online sources at ITP and PBS.