A need is dissatisfaction at a point of time and in a given context. Needs are distinguished from wants. In the case of a need, a deficiency causes a clear adverse outcome: a dysfunction or death. In other words, a need is something required for a safe, stable and healthy life (e.g. air, water, food, land, shelter) while a want is a desire, wish or aspiration. When needs or wants are backed by purchasing power, they have the potential to become economic demands. Basic needs such as air, water, food and protection from environmental dangers are necessary for an organism to live. In addition to basic needs, humans also have needs of a social or societal nature such as the human need to socialise or belong to a family unit or group. Needs can be objective and physical, such as the need for food, or psychical and subjective, such as the need for self-esteem. The concept of "unmet need" arises in relation to needs in a social context which are not being fulfilled. Needs and wants are a matter of interest in, and form a common substrate for, the fields of philosophy, biology, psychology, social science, economics, marketing and politics. To most psychologists, need is a psychological feature that arouses an organism to action toward a goal, giving purpose and direction to behavior. The most widely known academic model of needs was proposed by psychologist Abraham Maslow in 1943. His theory proposed that people have a hierarchy of psychological needs, which range from basic physiological or lower order needs such as food, water and safety (e.g. shelter) through to the higher order needs such as self-actualization. People tend to spend most of their resources (time, energy and finances) attempting to satisfy these basic before the higher order needs of belonging, esteem and self-actualization become meaningful. Maslow's approach is a generalised model for understanding human motivations in a wide variety of contexts, but must be adapted for specific contexts. While intuitively appealing, Maslow's model has been difficult to operationalize experimentally.
Daniel Thalmann, Ronan Boulic, Stéphane Gobron, Junghyun Ahn, Quentin Silvestre