NATURE VS. NURTURE
Can human behavior be explained as being ingrained in the genes before people are born, or is behavior developed by people over time in relation to their experiences in the external environment? According to Kleese (2001), this question has never been satisfactorily answered. The answers that have been provided are traditionally referred to as “The Nature vs. Nurture Debate.”
If the answer to the foregoing question is heavily weighted on the side of genetics and heredity as the prime contributor to the development of human behavior, the writer is said to be arguing Nature as the answer; however, if the argument is heavily weighted toward environment and experiences as the major contributor to behavior, then the writer is said to be arguing Nurture as the answer. The purpose of this paper is to briefly examine this debate and draw conclusions concerning its current status in the psychological literature.
Argument in Favor of Nature
Xu (2006) points out that while science has long known that certain physical traits (e.g., eye color) are determined by specific genes, the Nature argument states that more abstract psychobehavioral traits like personality, sexual orientation, aggression, intelligence and so forth are also encoded in an individual’s DNA. For example, it has been argued that being gay is genetically determined (Iemmola, & Camperio, 2008) as is criminal behavior (Pierei, & Levitt, 2008).
It should be noted that there is research that is supportive of genetics as a major influence on the development of human behavior. For example, Rutter (2006) reports that some of the strongest support for the Nature explanation consists of studies of identical twins. Although raised apart with no knowledge of one another, the similarities in behavior shown by identical twins are frequent and profound. However, despite some amazing similarities, there are also differences. This suggests that there are other factors at work beyond the contribution provided by DNA. In other words, the genetic/hereditary argument is supported but the argument as explanation for the development of human behavior is, at best, incomplete.
Argument in Favor of Nurture
Plomin and Colledge (2001) state that the Nurture argument holds that human behavior develops primarily from experiences that the person has during development, e.g., upbringing/parenting and other environmental factors. According to Shaffer and Kipp (2006), there are literally hundreds of studies of infant and child temperament and personality that support this argument. For example, it is known that the development of phobias and other mental conditions arise from classical conditioning learning mechanisms; while instrumental conditioning explains a host of other once thought to be genetic talents, penchants, abilities, tendencies, and so forth (Rutter, 2006). Current studies have even shown that humor is a learned trait (Rutter, 2006).
Given the foregoing, it can be said that while the studies of identical twins mentioned previously did show remarkable similarities, it is very likely that their differences are explained by differences in their experiences in life. In other words, the differences in the twin studies are explained by environmental differences. This is because if environment was not making a contribution, then the identical twin studies would have shown that the twins were similar in all aspects of their behavior.
This examination of the Nature vs. Nurture debate can be best understood in terms of the original question asked which was: Is our behavior ingrained prior to birth or is developed based on our experiences in the environment? The fact that there is research support for both arguments, leads to the conclusion that human behavior is a product of both nurture and nature. It would appear that our genes operate to increase the likelihood of certain behaviors but they are not fully deterministic in this regard. Rather, environment also makes its contribution and it is both our genes and our experiences that will ultimately play a large role in the behavior that we develop from birth to adulthood.