Table of Contents
The topic of genetics has not only attracted the attention of researchers across the globe, but has also raised the debate on a number of concerns on the human behavior. Development in genetics has a significant impact on the healthcare practice and the medical industry in general Miller, Ahern & Harvey (2005). There are those who support the ideal that human behavior is determined by genetic processes that reign over the ideal that human behavior develops from the environmental factors. The nature-nature debates explain this standoff. There is a need of establishing the truth; hence, the search for truth with joint propositions that both genes and environmental factors has influence on human behavior. Nonetheless, McGue & Bouchard (1998) observe that “the controversy surrounding the recent publication of The Bell Curve shows that the proposition genetic factors influence fundamental aspects of our human nature continue to inflame passions,” (p. 2). This essay explores how genetics and environment both influence the development of human behavior.
The study of human behavior with reference to genetics seeks modalities to substantiate the nature-nurture aspects of individual development resulting from the differences in phenotypic composition. As DiLalla, Mullineaux & Biebl (2012) buttress, it “focuses on the etiology of individual differences in behavior by seeking to understand the contribution of both genes and environments to individual variations in human behavior,” (p. 154). The phenotypic variances lead to possession of different human behaviors. In this study, the influence of genetic variance will be pegged on a consideration of both nature and nurture ideals in an attempt to develop a realistic explanation on the cause of human behavior because of these two aspects.
The environment has plays a role in the shaping of human genetics; hence, affect the behaviors of individuals. It is a scientific tradition in the developmental psychology that shared and nonshared factors of the environments affect individual behaviors. Nonetheless, behavior genetics studies have shown that the influence of psychological characteristics is dependent on the nonshared aspects of the environment. The nonshared environments that have a significant effect on the psychological traits of an individual can be categorized as pre and perinatal factors.
Joint Influence of Genes and Environment on Human Behavior
Correlation between Environment and Genotype
According to McGue & Bouchard (1998), there is a correlation between the environment and genotype on three different mechanisms due to irregular genotype assortment in different environments. The first environment is the passive genotype-environment correlation, which according to McGue & Bouchard (1998) “occurs when parents, who transmit to their offspring genes that might promote the development of a psychological characteristic, also provide a rearing environment that encourages the development of that characteristic,” (p. 16). This correlation has been observed on the cognitive ability during childhood that is inherited from parents. If the parents both have high Intelligence Quotient (IQ), in an environment that enhances child rearing, then the genes are likely to be transmitted to the child. The child will therefore develop high intellectual achievement.Want an expert to write a paper for you Talk to an operator now
The second genotype-environment mechanism is referred to as evocative genotype-environment correlation. This mechanism is based on the proposition that individual experiences are based on the genetically manipulated behavior to suit the views of others. For example, Pike et al. (1996) reported that “the association between parental negativity and both adolescent antisocial behavior and depression was genetically mediated, again implicating evocative genotype-environment correlational processes,” (McGue & Bouchard, 1998, p. 16). It is however critical to determine whether the production of reciprocal effects is a result of the evocative processes.
Research indicate that the there is substantive evidence to show that biological parents state of psychiatry has an association with that of an adoptive parents’ psychiatry (McGue & Bouchard 1998). This points out to the fact both genetic development and environmental factors influence the development of behavior. Evocative correlation between environment and genotype is mediated upon by adoptee antisocial behaviors. Foster, Sharp, Freeman & Chino (1999) that a person’s genetic information could pose collective risks among those who share similar environment or social identity, buttresses this observation. For instance, an adoptee’s antisocial behaviors would make a mother to develop harsh and inconsistent parenting that further aggravates the adoptee’s antisocial characteristics. Genes contribute up to 50% 0f the antisocial behavior of an individual’s traits (Moffitt 2005).
Finally, active genotype-environment correlation takes place when a person’s accede to life dispositions that have a significant effect on basic and secondary choices in life. For instance, it is possible that an individual will spend unwarranted time to watch television while another would rather take part in an active engagement. In addition, while other people would dedicate their time on education, others prefer to end their education a little bit earlier. These choices as posited by McGue & Bouchard (1998) “is likely to have both immediate and long-term effects on the nature of individual experience; each also appears to be partially heritable” (p. 17). Reactive and active processes in the genotype-environment correlation serve as a way of differentiating meaning and heritability for characters that have psychological connotations from those that are medical or physiological characteristics. Antisocial behaviors or specific interests that an individual may develop will depend on the process of mediation on the basic gene product and behavior. The choices that people make depend on the dispositional tendencies, which emanate from the dominant and active environmental opportunities.
It is quite difficult to demonstrate scientifically, the existence of a genotype-environment interaction (G-E) and the sensitive nature of the genotype to the surrounding. This is because individual psychological traits are difficult to express. Research by Bergeman et al. (1998) to establish the link between personality and cognitive ability did not yield positive results (McGue & Bouchard 1998).
“Replicable G × Es may mean that our intuitions are wrong and that the world is largely additive. Alternatively, and we think more plausibly, our methods may presently lack the precision to detect the existence of G × E effects,” (McGue & Bouchard 1998, p. 17). A good example of that shows the G × E behavior trait was the detection of phenylketonurias following the identification of obligatory environment and obligatory genotype. That was a conventional method and the current detections of G × E in the human behavior genotypes show no significant results. The importance of identifying the genes is to provide researchers with the human behavioral interest with models of systematic investigation into the G × E effect. For instance, DiLalla, Mullineaux & Biebl (2012) note that “The overall pattern of genetic and environmental effects appears to be a bit mixed overall early in childhood, but the typical observed pattern indicates that shared environmental influences may decrease over early childhood whereas genetic influences increase,” (p. 188).
Many studies have been dedicated to establishing whether sex differences have effects on antisocial behaviors. Sex differences affect antisocial behaviors to a small extent. Nevertheless, as noted above, the confusion about sex differences exist because scholars confuse behavior-genetics models. “The threshold model argues that because females experience gender%u2010role socialization against antisocial acts, any female who becomes antisocial must be under very strong genetic influence,” (Moffitt 2005, p. 66). To develop research in this spectrum further, molecular genetics research should be streamlined in order to give more insights into the sex differences and how it affects antisocial behaviors.
G-E correlations and interactions as highlighted above helps to differentiate the various phenotypes that determine an individual’s behavior, whether physiological or medical. The three mechanisms that have been used to study G-E correlations all indicate that both genetics and environment contribute to the development of individual traits. The social environment for instance can mediate the genetic development of an individual. The developed mechanisms will offer avenues for researchers to identify which models of G-E would be appropriate to study. This is because of the difficulty that scientific research faces in the studying the G-E interactions. The models therefore specify which aspects can be developed further. Molecular genetics have the potential to become a relevant leeway through which more insights into the field of genetics can be further developed. These technicalities explain why scholars have distinct views on the nature-nurture debates. This research calls for the medical practitioners to understand that environment and genetics influence each other in the development of human behavior.