What is Internal Motivation Extrinsic and Intrinsic Motivation what is External Motivation

Motivation to take action often comes from internal sources. The need to fulfill one’s own needs does not necessarily need to be externally motivated, and self-determination theory focuses on autonomy, competence, and relatedness, which are all intrinsic motivators. Similarly, instinct is an internal stimulus for behavior, but the behavior associated with instinct stems from an external source (Deckers, 2010, p. 28). Individuality plays a significant role in how much of a particular instinctive behavior is produced. For example, what frightens one person may not be intimidating to another, and the consequences of a lack of instinctive behavior could result in the demise of an individual organism. Instinct is a universal component of evolutionary behavior passed from one generation to the next, and is a critical part of determining the further evolution of a species. 

Deckers (2010) reported some interesting insight into self-determination and needs, according to renowned psychologist Henry Murray (1938). Once instigated, a need will persist as an electrical chemical process in the brain, which corresponds to a feeling of desire. Behaviors instigated by need cease when the goal of satisfying the specific need has been achieved. Needs can be evoked by an internal physiological process but also by environmental demands, which are either to be approached or avoided (p. 33).

In contrast to behaviors associated with evolution, some psychological needs are exaggerated because of external stimuli. The need to lose weight and to conform to the stereotypical image of being skinny is a major concern for psychologists and medical doctors who see increasing numbers of teenage girls battling eating disorders while trying to fulfill their own psychological need to be slim. The behaviors associated with dieting and weight loss are contradictory to feeding behaviors that come from evolutionary motivated behaviors. In ancient times, eating until one was satisfied was in line with an inborn instinct to survive. Not eating enough could lead to illness and subsequent death. Unfortunately, understanding the consequences of poor nutrition is not enough to help some young men and women overcome their need to be slim.

In an article about self-determination and unhealthy weight control behaviors, it is reported that “the struggle for body control might also represent a compensatory activity that manifests when individuals’ needs for competence and relatedness are thwarted” (Thogersen , Ntoumani, Ntoumanis & Nikitaras, 2010, p. 538).  Social isolation, lack of parental support, and a perceived lack of autonomy are just some of the psychological needs that are replaced with other behaviors detrimental to physical and psychological wellbeing. Examining these underlying needs is useful in predicting unhealthy eating behaviors in some people (Thogersen , et al, 2010, p. 544)

The absence of competence and autonomy is associated with more health-related behaviors than diet and exercise participation. Moreover, relatedness apparently plays a role in forming behaviors modeled by trusted friends and associates (Sharma & Smith, 2011, p. 3). According to Sharma & Smith (2011), literature regarding the relationship between self-determination theory and substance abuse, including alcohol, is currently scarce, and “future studies looking to evaluate SDT, alcohol, and drug abuse behaviors should further explore motivational factors over time as they relate to self-determination and treating alcohol and substance abuse” (p. 8). Self-determination theory and evolution theories help to explain only a minute part of the complex system of behaviors humans possess.

When processing the qualities considered attractive in a mate, humankind has relied on little more than an inborn knowledge of what traits are the most desirable. This knowledge promotes behaviors designed to entice the perfect partner.  Men and women sometimes share similar preferences when seeking a mate, however, “men display a higher mean level of sexual unrestrictedness than do women” (MacDonald, 2009, p. 180). Although evolution has allotted a number of similar values in both men and women, it is men who are reported to be more interested in short-term sexual relationships, rather than long term commitments “‘(Simpson and Gangestad, 1991;) Schmitt, 2005)’” (MacDonald, 2009, p. 180). The need to reproduce to ensure future generations are as strong and healthy as possible appears to be an evolutionary motivated behavior, rather than one of self-determination.


Deckers, L. (2010). Motivation: Biological, psychological, and environmental (3rd ed.). Boston, MA: Pearson/Allyn & Bacon.

MacDonald, K. (2009). Evolution, Psychology, and a Conflict Theory of Culture. Evolutionary Psychology, 7(1), 208-233. Retrieved from EBSCOhost.

Sharma, M., & Smith, L. (2011). Self Determination Theory and Potential Applications to Alcohol and Drug Abuse Behaviors. Journal of Alcohol & Drug Education, 55(2), 3-7. Retrieved from EBSCOhost.

 Thogersen-Ntoumani, C., Ntoumanis, N., & Nikitaras, N. (2010). Unhealthy weight control behaviors’ in adolescent girls: a process model based on self-determination theory. Psychology & Health, 25(5), 535-550. doi:10.1080/08870440902783628