A need is a motivational feature that prompts an organism to engage in some action toward a goal, giving purpose and direction to behavior. In the most widely known academic view, human needs can be categorized as physiological (basic) needs, safety needs, affiliation or belongingness needs, esteem or status needs and self-actualization. Most people spend most of their time and energy attempting to satisfy these basic needs before higher needs such as affection, affiliation or self-actualization become meaningful in their lives.
A number of different approaches to the study of need have been developed. The most influential academically has been the hierarchy of human needs developed by psychologist Abraham Maslow in 1943. Maslow posited that there are independent sets of distinct motives ranging from basic physiological (food, water) needs through affiliation and status needs, all the way up to self-actualization or personal growth. This theory arose out of observations that people tend to focus most of their energies and resources on meeting basic physiological and safety needs before they will invest their time in affiliation and status needs.
Another approach to the concept of need is that of economists Douglass North and Oliver Williamson. Their 1992 book, “The Need to Know”, advanced the theory that there are certain essential things that everyone must have in order to survive and thrive, such as health care and education. This is contrasted with the idea that most of what we want are simply extras that we could do without if we had to.
The terms need and want are often misused. For example, many people think of a need as something that must be obtained or else death will result, whereas the correct use of the term is to mean something that is a requirement or indispensable for life. For example, hunger is a need and a lack of it is a danger to life.
There is no simple solution to the question of how the details of need satisfaction should be determined, and there are competing arguments. For example, some researchers have emphasized the importance of rational identification of needs using up-to-date scientific knowledge; consideration of the actual experiences of individuals in their daily lives; and democratic decision-making. Others have emphasized the value of the capability approach of Martha Nussbaum and Amartya Sen. This approach contends that individuals with more internal “assets” or “capacities” will be able to meet more of their own needs.
Finally, some analysts have suggested that the hierarchy of human needs as formulated by Maslow is flawed. For instance, biological theories of life-history development suggest that the sexual needs of mating should be included in a separate category rather than viewed as a subset of physiological or safety needs. Similarly, the need for family and community support might also be considered a distinct category. Moreover, the analysis of functional differences suggests that Maslow has sometimes lumped together functionally and psychologically distinct motives into overly broad categories. For these reasons, a more precise model of human needs has been proposed by psychologists Deci and Ryan.