Maslow's hierarchy of needs is an idea in psychology proposed by American psychologist Abraham Maslow in his 1943 paper "A Theory of Human Motivation" in the journal Psychological Review. Maslow subsequently extended the idea to include his observations of humans' innate curiosity. His theories parallel many other theories of human developmental psychology, some of which focus on describing the stages of growth in humans. The theory is a classification system intended to reflect the universal needs of society as its base, then proceeding to more acquired emotions. The hierarchy of needs is split between deficiency needs and growth needs, with two key themes involved within the theory being individualism and the prioritization of needs. While the theory is usually shown as a pyramid in illustrations, Maslow himself never created a pyramid to represent the hierarchy of needs. The hierarchy of needs is a psychological idea and also an assessment tool, particularly in education, healthcare and social work. The hierarchy remains a popular framework in sociology research, including management training and higher education.

Moreover, the hierarchy of needs is used to study how humans intrinsically partake in behavioral motivation. Maslow used the terms "physiological", "safety", "belonging and love", "social needs" or "esteem", "self-actualization" and "transcendence" to describe the pattern through which human needs and motivations generally move. This means that, according to the theory, for motivation to arise at the next stage, each prior stage must be satisfied by an individual. The hierarchy has been used to explain how effort and motivation are correlated in the context of human behavior. Each of these individual levels contains a certain amount of internal sensation that must be met in order for an individual to complete their hierarchy. The goal in Maslow's hierarchy is to attain the level or stage of self-actualization.

Although widely used and researched, Maslow's hierarchy of needs lacks conclusive supporting evidence and the validity of the theory remains contested in academia. One criticism of the original theory which has been revised into newer versions of the theory, was that the original hierarchy states that a lower level must be completely satisfied and fulfilled before moving onto a higher pursuit; there is evidence to suggest that levels continuously overlap each other. Other criticisms include the placement location of sex in the hierarchy, the assumption of individualism in the theory, and lack of accounting for regional variances in culture and availability of resources.