Maslow studied what he called exemplary people such as Albert Einstein, Jane Addams, Eleanor Roosevelt, and Frederick Douglass rather than mentally ill or neurotic people, writing that "the study of crippled, stunted, immature, and unhealthy specimens can yield only a cripple psychology and a cripple philosophy." Maslow studied the healthiest 1% of the college student population.
Maslow's theory was fully expressed in his 1954 book Motivation and Personality. While the hierarchy remains a very popular framework in sociology research, management training and secondary and higher psychology instruction, it has largely been supplanted by attachment theory in graduate and clinical psychology and psychiatry.
Hierarchy
Maslow's hierarchy of needs is often portrayed in the shape of a pyramid with the largest, most fundamental levels of needs at the bottom and the need for self-actualization at the top.[1][9] While the pyramid has become the de facto way to represent the hierarchy, Maslow himself never used a pyramid to describe these levels in any of his writings on the subject.
The most fundamental and basic four layers of the pyramid contain what Maslow called "deficiency needs" or "d-needs": esteem, friendship and love, security, and physical needs. If these "deficiency needs" are not met – with the exception of the most fundamental (physiological) need – there may not be a