Needs Theories

While there are multiple theories of motivation, there are a few that are very similar. These ones are Maslow's Hierarchy of Needs, Alderfer's ERG theory and Mcclellan's Acquired Needs Theory. All three of these theories are based on a human's perceived needs and wants.

Hierarchy of Needs 

Abraham Harold Maslow was a psychologist and a professor that published a highly influential paper in 1943 called A Theory of Human Motivation. In this paper, he outlined “five motivational needs, often depicted as hierarchical levels within a pyramid" (Maslow's Hierarchy of Needs, 2007) such as the one below.

(Rosen, 2011)

 While the order may not necessarily be the same for everyone, Maslow theorized that these were the needs that motivated all humans. His theory was later expanded to include cognitive, aesthetic and transcendence needs. Cognitive needs referred to the need of knowledge and meaning, while aesthetic needs were the "appreciation and search for beauty, balance, form" and transcendence needs were "helping others to achieve self-actualization" (Maslow's Hierarchy of Needs, 2007).

ERG Theory 

Clayton Alderfer's simplified Malsow's Heirarchy of Needs, suggesting that "all human needs can be accessed and satisfied simultaneously, rather than from the bottom up" (Maslow's Hierarchy of Needs, 2007). His ERG theory consisted of three needs:

• Existence - the most basic level 
• Relatedness - the need for "satisfying interpersonal relationships" 
• Growth - the need for "personal growth and development" (Kadian-Baumeyer)

When comparing Alderfer's ERG theory to Maslow's Hierarchy we can see how Alderfer's needs relate to the different levels in the pyramid.

(Alderfer's ERG Theory: Understanding the Priorities in People's Needs)

Alderfer's theory has more flexibility than Maslow's, while still retaining some sort of order. He also claims that the levels are "not as fixed as it is in Maslow's hierarchy" (Alderfer's ERG Theory: Understanding the Priorities in People's Needs) and can change from person to person..

Acquired Needs Theory 

David Mcclellan's Acquired Needs Theory slightly deviates from the other two, stating that "specific needs are acquired over time and are shaped by one's life experiences" (McClelland - Theory of Needs). He categorizes these needs into three categories: achievement, affiliation and power. The need to "accomplish something difficult", "form close personal relationships" and the need to "control others" (Theories of Motivation). Needs can be measured through the Thematic Appreciation Test, in which the test taker interprets image, like the one below, into a story.

(TAT)

Conclusion 

All of these theories are based around needs that either come biologically, culturally or through experience. These three scientists agree on the fact that motivation comes from a certain need and that need is what drives a person to go after certain goals.

References

Alderfer's ERG Theory - Existence, Relatedness, and Growth. (2012, January 1). Retrieved March 28, 2015, from http://www.leadership-central.com/erg-theory.html#axzz3VhZYkaiQ

Alderfer's ERG Theory: Understanding the Priorities in People's Needs. (n.d.). Retrieved March 28, 2015, from http://www.mindtools.com/pages/article/newTMM_78.htm

Kadian-Baumeyer, K. (n.d.). Alderfer's ERG Theory & Employee Motivation in the Workplace. Retrieved March 28, 2015, from http://study.com/academy/lesson/alderfers-erg-theory-employee-motivation-in-the-workplace.html

Maslow's Hierarchy of Needs. (2007, September 17). Retrieved March 28, 2015, from http://www.simplypsychology.org/maslow.html

Maslow, A. (2000, August 1). Classics in the History of Psychology -- A. H. Maslow (1943) A Theory of Human Motivation. Retrieved March 28, 2015, from http://psychclassics.yorku.ca/Maslow/motivation.htm

McClelland - Theory of Needs. (n.d.). Retrieved March 28, 2015, from http://www.netmba.com/mgmt/ob/motivation/mcclelland/

Rosen, L. (2011, October 7). Maslow’s Hierarchy of Needs. Retrieved March 28, 2015, from http://www.21stcentech.com/transportation-part-6-the-21st-century-and-the-automobile-what-will-we-use-to-make-them/maslow/

TAT. (n.d.). Retrieved March 28, 2015, from http://www.utpsyc.org/TATintro/

Theories of Motivation. (n.d.). Retrieved March 28, 2015, from http://www.analytictech.com/mb021/motivation.htm