
Maslow’s hierarchy of needs is a theory in psychology, proposed by Abraham Maslow in his 1943 paper A Theory of Human Motivation.
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. With the exception of the most fundamental (physiological) needs, if these “deficiency needs” are not met, the body gives no physical indication but the individual feels anxious and tense. Maslow’s theory suggests that the most basic level of needs must be met before the individual will strongly desire (or focus motivation upon) the secondary or higher level needs.