Personality is the varying behaviours of a person that is exclusive from other individuals in the populace. Eysenck's theory of personality emphasizes on the natural nature in the introduction of personality. It had been described that the introversion-extraversion characteristic sizing is biologically based mostly in different levels of arousal of the brain (Eysenck, Eysenck & Barret, 1985). Twin studies also claim that the shared environment play a minimal role in one's personality development. However, it generally does not mean that environment does not have any effect on the introduction of personality. Actually, both genetic factors and environment can play a part in developing an individual's personality. Through research, it is realized that the introduction of a person's personality is the result of both environmental and hereditary components respectively. To get a clearer treat this, it is better to locate a good example of a personality and from then, take a look at the role environment and genes play onto it. Relation between maternal depression and antisocial personality, along with another research of suicidal behaviours, can clearly apprehend the role in which both genetic and environment factors play on the development of personality.
Studies have advised that personality characteristics are inspired by their genetic history, and one common way to check on the heritability of personality attributes is by comparing similar twins with fraternal twins. Equivalent twins have a close hereditary match while fraternal twins reveal 1 / 2 of their genes. Since identical twins will be more genetically similar, it gives the closest possible marriage between two individuals in terms of genetic cosmetic, which is useful in studies personality. Thus, identical twins would become more similar than fraternal twins, if genes were to play a role in the introduction of personality. Similar characteristics in indistinguishable twins would be hereditary, and what's different would be thought to be environmental. If indistinguishable twins were more similar in lab tests for personality traits, it means that genetic factors have a significant amount in accounting for personality qualities. In the study of Loehlin, McCrae, Costa and John (1998), they developed three different measures from questions used in the National Merit Twin Review and applied behaviour-genetic models from what the three options have in common, and also to the distinctions. The results showed that Big Five personality qualities were largely inspired by genes, with a tiny percentage consisting ramifications of unique individual encounters, momentary situations and gene-environmental relationships, when compared with shared family environment, which got minimal results to the five proportions of personality features. Therefore, an individual's long-lasting personality is highly reliant on genes, and usually independent of shared environment (Loehlin et al. , 1998).
By targeting a good example of a personality, you can compare environmental and genetic effects about how this personality originated. For instance, in the case of antisocial personality, Kim-Cohen, Moffitt, Taylor, Pawlby and Caspi (2005) do a study to learn the relationship between maternal major depression and children's antisocial behaviour. Twin pairs were analyzed through the first five many years of life, with age seven for antisocial personality which, by then, would get rid familial accountability. It was hypothesised that children's antisocial behavior is due to the caregiving environment being afflicted by a mother's depression, presence of any antisocial personality in the mother, marriage with antisocial men, or inheritance of genes from mother with an antisocial personality. Frustrated mothers tend to provide inadequate parenting, little relationship and tense family circumstances that lead to behavioural problems for his or her children. This is visible by the significantly higher levels of antisocial behavior at age seven, when the mom was depressed through the children's first five years of life (Kim-Cohen et al. , 2005). Furthermore, maternal melancholy that happened after, not before, children's birth was deeply related to children's antisocial behaviour. Thus, this suggests that antisocial personality developed in children is caused by the family environment.
Also, it is fair to say that children of despondent mothers would share higher antisocial behavior, when compared with children of nondepressed mothers, regardless of any antisocial personality disorder (ASPD) symptoms in the mom. Indeed, results from the study discovered that among children whose moms acquired no symptoms of ASPD, children with a frustrated mother experienced higher antisocial behaviour at era seven as compared to children of nondepressed moms (Kim-Cohen et al. , 2005). Additionally, after controlling maternal ASPD symptoms and biological father's ASPD symptoms in split tests, maternal unhappiness could successfully predict children's antisocial behaviour at era seven. Evidently, maternal major depression through the children's first five years of life plays a part in the introduction of children's antisocial personality. Individual of parental ASPD symptoms, maternal depression could predict a child's antisocial behaviour, implying that it is the surroundings that shapes an individual's antisocial personality. Next, depressed women are likely to marry and keep children with antisocial men. Antisocial fathers tend to be ambitious or abusive, creating a disfavoured family environment. As both parents are affected by either unhappiness or antisocial behavior, this creates an impaired family environment for the children, and so increasing the inclination of antisocial final results in the kids.
Besides the family environment that triggers antisocial behavior of children, hereditary factors can be in charge too. Research shows that antisocial fathers copy their genes for antisocial behaviour to children even though they are not in the children's lives (Sara, Moffitt, Caspi & Taylor, 2003). Also, adoption studies claim that if biological moms have the basis for antisocial personality, their children will also show an antisocial behavior when used and cared for in some other environment. Thus, this hereditary liability in children of stressed out moms discredits the view that the children's antisocial behavior is brought on by poor caregiving environment.
In another example, individuals who have devoted suicide, or attemptedto suicide, have been found to exhibit hostile, neurotic, and competitive personality (Wasserman, Geijer, Sokolowski, Rozanov, Wasserman, 2007). To analyse the contribution of genes and environment to these personalities, it is very important to consider suicide studies, where environmental factors such as negative life events often donate to suicidal behaviour. However, environmental factors do not entirely cause suicidal tendencies, since individuals who are subjected to the same negative environmental stress do not exhibit the same suicidal behaviour. Acknowledged causes of suicidal behaviours include mental health problems, personality disorders and distressing life situations and these do not necessarily lead to suicide, or an effort to suicide. Thus, it is possible to say that there is a significant genetic component to hostile personality in suicidal behaviour.
To examine this likelihood of genetic factor, Wasserman et al. (2007) have an on-going project, genetic inspection of suicide and suicide make an effort (GISS), which try to identify genes relevant to suicidal behaviour. It was discovered that a variant of individual T-box 19 (TBX19) eventually give an increased response with regard to adrenocortical hormones, explaining the relationship between the hostility characteristic and the genetic variance at the TBX19 locus (Wasserman et al. , 2007). Replication of sample data used in the study recommended that it was reliable to conclude that genetic variation at the human TBX19 locus relates to hostile personality. Therefore, genes do play a role in the introduction of personality. Furthermore, in family studies, family of people who already devoted suicide or attempted to commit suicide will probably have higher level of suicidal behavior as compared to those family members that do not have any suicidal background (Brent et al. , 2002). Also, twin studies show that indistinguishable twins have higher probability to successful and attempted suicide included in this as compared to that among fraternal twins (Statham et al. , 1998). Thus, one cannot neglect the role genes play in the development of personality.
In conclusion, both the environment and genetic configuration are essential determinants of a person's personality. One also has to look at the conversation between genetics and environment for a definite understanding on personality development. Differing people with certain genotypes tend to blend into an environment which they deem to be suited or comfortable. Therefore, you'll be able to say that genes make the surroundings one will project in. However, this can even be seen from a different viewpoint. Individuals, who are already created into a certain type of environment, unknowingly bring out or develop certain personality characteristics to blend in and match their environment. Thus, it is very difficult to look for the actual contributions of gene and environment to personality features.