Maslow’s Need Hierarchy Theory Maslow’s Need Hierarchy Theory of motivation was derived from the clinical research of psychologist, Abraham Maslow in 1943. This popular theory describes a pyramid which identifies five basic human needs, which drive human behavior. He suggests that individuals are motivated or inspired by their unmet needs. The pyramid structure of these need components identifies this from most basic to not as basic. The higher one is not met until the one before has been actualized. Those needs are: physiological, safety, love, esteem, and self-actualization respectively. They are also called deficiency needs or D-needs, meaning that these needs are a result of deprivation. Satisfying these lower-level needs is important in order to avoid unpleasant feelings or consequences. Physiological needs, according to Maslow, the most basic of needs, include a sufficient supply of food, air, and water for survival. All other needs are secondary to these instinctive needs. Safety needs are the necessity of security from harm or danger, both physically and psychologically. These survival necessities include a desire for steady employment, health insurance, safe neighborhoods, and shelter from the environment. The third need is love. This encompasses the yearning to be loved, as well as to love others. It includes a desire to belong and to gain affection from others. Romantic relationships, friendships, and family interactions fulfill this need for companionship and acceptance. Participation in social, community, or religious groups also help to meet this need. Esteem is the fourth need on the pyramid of hierarchy. It is the longing for prestige and recognition from others. It also includes a need for a reputation. It calls for inner strength and self-confidence. The least of the basic needs is self-actualization. This means to be aware of oneself and cognizant of one’s personal growth. When people are self-aware, they are less concerned with the opinions of others, and more interested in fulfilling their own potential. Achieving self-actualization is becoming the best that one can be. As one of the above needs is fulfilled, the next unmet need becomes more prevalent. Maslow believed that the first has to be actualized in order to be motivated to achieve the next. It is difficult to focus on the latter without the first being satisfied.

Alderfer’s ERG Theory Clayton Alderfer was an American psychologist who further developed Maslow's hierarchy of needs by categorizing the hierarchy into his ERG theory. ERG is an acronym for Existence, Relatedness, and Growth. Alderfer re-categorized Maslow’s hierarchy of needs into three broader classes: Existence, Relatedness, and Growth. Existence is the need for basic material necessities, which are physiological and physical safety needs combined. Relatedness includes an individual’s aspiration for maintaining significant interpersonal relationships with family, peers and/or superiors. It includes acquiring public recognition and notoriety. It is similar to Maslow’s social and esteem category of needs.
Growth is the need for self-development, personal growth, and advancement. It is compared to the Maslow need of self-actualization. Esteem is also identified in this category.
According to the ERG Theory, more than one need can be in action simultaneously. One does not have to be met before another. Individuals have a variety of needs which must be achieved at the same time in order for them to be properly motivated. If the higher needs are not met, a person might regress to the lower for satisfaction. All need must be considered for motivation to take place and advance in personal growth.
McClelland’s Need Theory This Need Theory was created by psychologist, David McClelland. He stated that needs for achievement, affiliation, and power affect the actions of people. He attached a