According to humanistic psychologist Abraham Maslow, all individuals strive to become self-actualized, or reach their fullest potential; however, in order to do so, a series of needs must first be satisfied.  These needs are arranged in a hierarchy beginning with physiological needs and ending with self-actualization.  The needs of each level on the hierarchy cannot be addressed until the needs beneath them have been met.  These basic and universal needs are referred to as conative needs, which means that they have a striving or motivational nature.  They include (in order) physiological needs, safety needs, love and belongingness needs, esteem needs, and self-actualization needs.

In contrast to conative needs, aesthetic needs are not basic or universal in nature.  These needs involve beauty and aesthetically pleasing experiences.  In the same way that people respond when their basic needs are not met, individuals with strong aesthetic needs often experience stress and sickness when these needs are not met.

Cognitive needs refer to the desire to know, understand, and solve problems.  People with strong cognitive needs are often described as curious and inquisitive.  According to Maslow, when cognitive needs are blocked, all of the conative needs on the hierarchy are threatened.  In other words, knowledge is imperative to satisfying each of the conative needs.  For example, in order to meet physiological needs, a person must know how to attain food and shelter.

In order to maintain optimum physical and psychological health, conative, aesthetic, and cognitive needs must be satisfied.  In contrast, neurotic needs are not productive and typically lead to pathology.  These needs are usually reactive in nature and serve to compensate for some basic need that has gone unsatisfied.  For example, it has been suggested that anorexia nervosa sometimes serves as a pathological mechanism for control.  Neurotic needs inhibit personal growth and prevent individuals from reaching a state of self-actualization.