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Genomics in the Media
Click here to see the journal article. "A mechanistic explanation of popularity: Genes, rule breaking, and evocative gene-environment correlations" (Burt, 2009)
The journal article’s introduction explains the contextual background necessary to understand where this study fits in with prior knowledge, and expounds on the purpose of the study. Burt (2009) begins by defining popularity as how much an individual is liked by peers. Importantly, it is acknowledged that the study was not an isolated foray, but rather builds upon previous research and adds to the knowledge of causes of popularity (Burt, 2009).
The first section explains the study’s focus on one behavior’s mediatory role towards popularity. Although several aspects of an individual can influence the popularity status of an individual, one previously documented behavior is rule-breaking behavior (RB) as seen during male adolescence (Burt, 2009). RB is beneficial/adaptive when practiced by an adolescent, is temporarily expressed only during adolescence (not life-long RB), and is partly done due to desire/social pressure to imitate friends (Moffitt, 1993). Because RB is “admired and encouraged” by other adolescents, the male adolescent who practices RB will be more likely to be popular (Burt, 2009). Variable RB expression has been linked to various genetic variations in different individuals (Burt, 2009). Because of this association between genetics and RB, and between RB and popularity, it is possible that popularity has a genetic basis through the mediatory role of RB (Burt, 2009).
The next section focuses on popularity’s relation to the biological role of serotonin and the serotonin receptor. In animal studies using sertonergic-enhancing drugs, and in human studies using SSRI, serotonin was found to increase behaviors making someone more likable, likely leading to more popularity (Burt, 2009). This paper’s study focused on the 5HT2A serotonin receptor (figure 1), but specifically a polymorphism in the receptor gene, -G1438A, because a previous study by Burt found that “those with the G-allele were significantly more popular than those with the A-allele” (Burt, 2009). There is no claim of direct linkage between genetics and popularity; instead, Burt introduces the concept of an evocative gene-environment correlation (rGE) which proposes that genes mediate behavior, which mediate “social consequences;” however, this concept had not been directly demonstrated by previous studies.
Burt goes on to summarize the study’s objectives. The purpose was to demonstrate the concept of evocative rGE by showing that 5HT2A -G1438A mediates RB, which mediates popularity (Burt, 2009). The reason that RB was chosen to be studied was because of its links to popularity and serotonin (Burt, 2009). The hypothesis was the “5HT2A -G1438A and popularity could be at least partially mediated via RB” (Burt, 2009).
Figure 1: Different molecular illustrations of the 5HT2A serotonin receptor along with 5HT (serotonin) binding areas. Permission granted by BIO-BALANCE (http://www.bio-balance.com/BB5.html).
Two independent groups of late-adolescents were selected for the study (Burt, 2009). To test for 5HT2A -G1438A polymorphism, the procedure involved getting saliva for DNA samples (Burt, 2009). To test for RB, the procedure involved participation in a group party planning session and a subsequent “sociometric questionnaire” (Burt, 2009). Popularity was measured using the partner effect (likability of an individual by others), which allowed for direct testing of the concept of evocative rGE (Burt, 2009). A composite RB score was calculated using the questionnaires (participants scoring likability of other participants, RB of themselves and their friends) and observer ratings (from researchers viewing videotaped sessions) (Burt, 2009).
Results and Discussion
The results indicate how much RB mediated the association between -G1438A and popularity (Burt, 2009). The discussion talks about the importance/meaning of the new knowledge discovered in the study. Analysis found a significant positive association between RB and popularity (Burt, 2009). Several different tests found significant association of -G1438A towards both RB and popularity; specifically, RB accounts for 21% of the association between -G1438A and popularity (Burt, 2009). The study’s results are significant because the data supports the concept of evocative rGE, where 5HT2A -G1438A mediates RB, which mediates popularity (Burt, 2009). The study was purported by Burt to be “the first to explicitly identify a pathway” that genes influenced popularity (Burt, 2009).
There are several caveats that limit the scope of the findings. The results are relevant only towards new acquaintances, and are not indicative of what contributes to popularity in “more lasting peer relationships” (Burt, 2009). The study only considers RB temporarily expressed during adolescence, which is linked to popularity; other types of RB such as life-long RB and/or aggressive RB are not linked to popularity, but rather “social rejection” (Burt, 2009). Only interactions between boys were considered in this study; in contrast, interactions between girls or in boy/girl interactions would likely diminish RB mediation towards popularity (Burt, 2009).
Avenues for further research would involve studying longer term relationships, and other genetic factors of popularity for girls, boy/girl networks (Burt, 2009).
Other caveats are directly associated with the genomic complexity of the relationship between popularity, behavior, and genes. The study was limited by focusing only on one polymorphism of 5HT2A -G1438A (Burt, 2009). The study was also limited by focusing on RB since most of the association between -G1438A and popularity (around 79%) was accounted for by other unknown aspects besides RB (Burt, 2009). One of the two sampling groups exhibited a less than significant association between -G1438A and RB (Burt, 2009). This difference between the groups was likely due to RB being polygenic, meaning it is mediated by more than one gene besides -G1438A (Burt, 2009).
Further research would need to look at other polymorphisms of -G1438A or conduct a more comprehensive look at other “candidate genes” associated with behaviors/aspects that influence popularity (Burt, 2009). Another journal article focuses not on RB, but on the demonstrated heritability of individual aspects such as the likability of an individual and how well an individual brings together/introduces friends in a “social network” (Frowler et al., 2009). While there are no implicated genes mentioned in the study, it is probable that there may be many genes and genomic factors that account for why some individuals are better at creating “social networks” than others (Frowler et al., 2009). Genomics takes into account that it is not merely “one gene--one function--one phenotype;” instead, there are many complex interactions between genes, proteins, and cells that may result in RB or other personal aspects that mediate popularity (Campbell and Heyer, 2007).
Burt, S. Alexandra. "A Mechanistic Explanation of Popularity: Genes, Rule Breaking, and Evocative Gene-environment Correlations." Journal of Personality and Social Psychology 96.4 (2009): 783-94. <http://web.ebscohost.com/ehost/detail?hid=12&sid=1b568042-b585-4f2f-b18b-6491e2ad22d5@sessionmgr14&vid=3&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ==#db=pdh&AN=psp-97-1-57>.
Campbell, A. M., and Laurie J. Heyer. Discovering Genomics, Proteomics, and Bioinformatics. 2nd ed. San Francisco: Pearson Education, 2007. Web. 24 Jan. 2011.
Fowler, J. H., C. T. Dawes, and N. A. Christakis. "Model of Genetic Variation in Human Social Networks." Proceedings of the National Academy of Sciences 106.6 (2009): 1720-724. <http://www.pnas.org/content/106/6/1720.full>.
Moffitt, T. E. (1993). Adolescence-limited and life-course-persistent antisocial behavior: A developmental taxonomy. Psychological Review, 100, 674-701.
5HT2A. Photograph. BIO BALANCE: A Biotechnology/Pharmaceutical Discovery Company. Web. 28 Jan. 2011. <http://www.bio-balance.com/BB5.html>.
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