The Etiology of Aggressive and Nonaggressive Antisocial Behaviour - Literature review Example

Critique: ‘A Longitudinal Behavioural Genetic Analysis of the Etiology of Aggressive and Nonaggressive Antisocial Behaviour’ by Thalia C. Eley, Paul Lichtenstein and Terrie E. Moffitt Popular Culture Student’s Name: Name of Institution: Instructor’s Name: Course Code: Date of Submission: Introduction (Problem Statement and Purpose) Eley et al (2003) begin this paper begins by identifying the two groups of antisocial behavior (ASB); aggressive and nonaggressive. In the end, the paper is a result of the efforts of Eley et al (2003) to investigate how genetics and environment influence both the aggressive and nonaggressive ASB. From the onset, the researchers agree that both genetics and environment influence behavior. But they also recognize that these factors could influence the two groups of behavior differently. In the end, the researchers seek to answer the question: how exactly does genetics and environment influence ASB and in which case (aggressive or nonaggressive) is the influence of genetics or environment stronger? In this respect, the researchers study these aspects on two twin groups: twin pairs between 8-9 years of age and 13-14 years of age. Literature Review Eley et al (2003) explore some of the key terms and concepts of behavioral studies, which then inform some of the key assumptions they make. First, research has apparently shown that ASB in childhood is likely to continue into adulthood, and can be used to predict one’s ASB or crime in adulthood. In contrast, while it has been noted that ASB increases significantly in adolescents, these are normally short-lived and mostly fade away in adulthood (Laub & Sampson, 2001). Secondly, despite these characters of ASB at different stages of human growth and development, close examination reveals considerable heterogeneities. For instance, empirical studies in the cross-sectional studies distinguish two ASBs: aggressive and nonaggressive (delinquent) (Loeber & Hay, 1997). Aggressive ASB include ‘aggressive’ physical acts like hitting, bullying and fighting, as well as ‘aggressive’ personality like bragging, hot temper and arguing, etc. Delinquency (nonaggressive ABS) refers to rule-breaking acts such as vandalism, drug abuse, theft, truancy, etc. These are usually performed with peers. Considering these developmental and heterogeneity characters of ASB, Eley at al (2003) needed to find a way to integrate them. Moffit (1993) proposed two developmental ASB subtypes: ‘life-course-persistent’ ASB and ‘adolescent-limited’ ASB. ‘Life-course-persistent’ ASB is the result of some underlying temperamental trait probably having some biological basis (difficult temperament and neuropsychological deficits) which cause a person’s interaction with his/her the environment to not only promote, but also sustain ASB. ‘Adolescent-limited’ ASB, on the other hand, is likely to reveal circumstances or contexts that influence, for instance, peer affiliations, as well as the use of reinforcement and mimicry. In the end, the theory suggests that since the former has to do with heritable elements of temperament, it is likely to be more genetically influenced than the latter. This is, in a nutshell, the backdrop against which this research paper rests. Research Question & Methodology As already mentioned in the introduction part of this paper, Eley et al’s (2003) research seeks to answer the question: how do genetics and environment influence ASB? This is especially in line with the research hypothesis that “aggressive behavior ASB is a stable heritable trait as compared to nonaggressive behavior, which is more strongly influenced by the environment and shows less genetic stability over time” (Eley et al 2003). Looking at these questions and hypothesis it is obvious that this research has adopted a qualitative approach as it seeks to examine, understand, describe and explain the aspects relating to the causes of ASB (Catherine 2002). Generally, this research employed a non-probability sampling technique (Catherine 2002). In this respect, the researchers first decided to focus their research on twins. The paper then quotas the sample (Catherine 2002) into two groups: 8-9 year olds and 13-14 year olds. The researchers obtained the sample of twin groups involved in the study from the Swedish twin Registry. The researchers then contacted all the parents of the twins born in the period May 1985 and December 1986 in the 1994 through mailed questionnaires. Of the initial 1480 twin pairs, 1241 (about 84%) responded. The sample of twins used was also based on their zygosity: monozygotic (if they were ‘alike’) and dizygotic (if they were ‘not alike’). This was tested in various ways, e.g. questionnaires to parents and to the twins. The researchers used a number of ways to measure the variables of the study. For instance, parents completed CBCL, which is global model used to measure behavior in both children and adolescents for the past 6 months. In this model, the researchers used Aggression and Delinquency subscales for analyses. According to Achenbach (1991, cited in Eley et al 2003), these subscales possess good psychometric qualities. In this particular research, the Aggression subscale consists of 19 items, e.g. physical aggression such as fighting, destruction of property, bragging, jealousy, etc. The Delinquency subscale consists of 13 items, e.g. cheating, truancy, etc. To ascertain the generalizability of the sample used, the researchers compared their CBCL data with others, e.g. American versus Swedish CBCL data samples. Findings & Conclusions Ultimately, Eley et al (2003), outline their findings in the research. The main finding is that there are indeed different factors that lead to both aggressive and nonaggressive ASB. This is not to say that the two categories of ASBs do not have any etiological similarities. For instance, Eley et al (2003) conclude that while aggressive ASB in childhood is a result of genes, nonaggressive ASB is a result of both genes and environmental influences. But the same distinctions are not as obvious in adolescents in whom both genetics and environment influence aggressive and nonaggressive ASB the same way. According to Moffit’s (1993) taxonomic theory, life-course-persistent antisocial personality is a result of the cumulative interaction(s) between the a child’s initial genetic constitution and the environmental context (both at home and school). In other words, while Aggression is genetically influenced in childhood, it is increasingly influenced by the environment as the child ages. On the other hand, Delinquency is more environmentally-influenced across all ages. It is thus harder to distinguish the etiological differences of ASB in children and adolescents. Eley et al (2003) also sought to mark out the causes of continuity of ASB over time. In other words, they sought to answer the question: what causes ASB (aggressive or nonaggressive) to be carried on into adulthood? In line with the hypothesis, the research found continuity of genetic influences to be the cause of continuity in aggressive ASB. This continuity was also measured in relation to how childhood aggressive ASB develops into adolescent nonaggressive ASB (Eley et al, 2003). The research did not however find shared environment to have much influence on continuity in aggressive ASB, rating it at only 8%. However, when it came to continuity in nonaggressive ASB, the research found that shared environment a bigger role (54%). This is more than the influence of genetics on continuity of nonaggressive ASB (44%). Nonshared environment played a lesser role in continuity. The research also confirmed that genes have the ability to influence behavioral outcomes. This is as a result of several factors/mechanisms: direct main effects (i.e. monoamine acid) (Sabol, Hu & Hammer, 1998); gene-environment correlations, which simply means that there is a possibility for an individual to be genetically sensitive to certain elements of the environment (i.e. passive, active and evocative correlations) (Eley et al 2003). Shared environment (i.e. factors such as family criminality, poverty, poor child-rearing behavior) was also found to have significant influence (especially) on nonaggressive ASB during childhood and adolescence. Contrary to this, non-shared environmental factors vary with time (i.e. time-specific). Without having to go into the details of Eley et al’s (2003) research findings, it is important to assess and evaluate the validity of these findings, both in terms of general elements of research and the specific objectives of this research. First, it is important to note some of the limitations of this research- especially as admitted by the researchers themselves and what implications these have on the findings. First, the research relies on data from parent report, which may be biased (e.g. overplay twin correlations and shared environment factors, etc.). Still, these data are not dismissible since recent self-reported delinquency studies show relatively the same results. The second limitation has to do with the use of twins. Since twins are of the same ages and may share the environment, using them may not reveal clears ASB trends across ages and contexts. However, studies on twins have been found to show relatively the same results. Third, the research does not use the sample drawn from the peak ASB age, which is around 16 years of age. Unfortunately, this limitation is not satisfactorily explained or dealt with. Despite these limitations, they do not seem to have much implication on the findings of the paper. This is especially discernible considering that other research studies (some of which are cited here) have found more-or-less the same results. It is possible that the research may be biased, more inclined towards pointing out the elements that confirm the research hypothesis. Still, if the research is to be judged on its own, then the paper looks objective enough to offer valid findings. References Achenbach, T.M. (1991). Manual for the Child Behaviour Checklist and 1991 Profile. Burlington, VT: University of Vermont, Department of Psychiatry. Catherine, D. (2002). Practical Research Methods, New Delhi: UBS Publishers’ Distributors Eley, T.C., Lichtenstein, P. & Moffit, T.E. (2003). A Longitudinal Behavioural Genetic Analysis of the Etiology of Aggressive and Nonaggressive Antisocial Behaviour. Development and Psychopathology, vol. 15, pp. 383–402 Laub, J.H. & Sampson, R.J. (2001). Understanding Desistance from Crime. In M. Tonry (ed.), Crime and Justice: Annual Review. Chicago: University of Chicago Press. Loeber, R. & Hay, D.F. (1997). ‘Key Issues in the Development of Aggression and Violence from Early Childhood to Early Adulthood’, Annual Review of Psychology, vol. 48, pp. 371-410 Moffit, T.E. (1993). ‘Adolescence-limited and Life-course-persistent Antisocial Behavior: A Development Taxonomy. Psychological Review, vol. 100, pp. 674-710 Sabol, S., Hu, S., & Hamer, D. (1998). A Functional Polymorphism in the Monoamine Oxidase A Gene Promoter. Human Genetics, vol. 103, no. 3, pp. 273-279 Read More