Leadership personality type

A leadership personality type occurs in individuals with two long forms of transporter region (5-HTTLPR) of the serotonin transporter gene.

5-HTTLPR (serotonin-transporter-linked polymorphic region) is a degenerate repeat polymorphic region in SLC6A4, the gene that codes for the serotonin transporter. Since the polymorphism was identified in the middle of the 1990s,^[1][2] it has been extensively investigated, e.g., in connection with neuropsychiatric disorders. A 2006 scientific article stated that "over 300 behavioral, psychiatric, pharmacogenetic and other medical genetics papers" had analyzed the polymorphism.^[3]

The polymorphism occurs in the promoter region of the gene. Researchers commonly report it with two variations: A short ("s") and a long ("l"), but it can be subdivided further.^[4] In connection with the region are two single nucleotide polymorphisms (SNP): rs25531 and rs25532.^[5]

One study published in 2000 found 14 allelic variants (14-A, 14-B, 14-C, 14-D, 15, 16-A, 16-B, 16-C, 16-D, 16-E, 16-F, 19, 20 and 22) in a group of around 200 Japanese and Caucasian people.^[4] The difference between 16-A and 16-D is the rs25531 SNP. It is also the difference between 14-A and 14-D.^[3]

Some studies have found that long allele results in higher serotonin transporter mRNA transcription in human cell lines. The higher level may be due to the A-allele of rs25531, such that subjects with the long-rs25531(A) allelic combination (sometimes written L_A) have higher levels while long-rs25531(G) carriers have levels more similar to short-allele carriers. Newer studies examining the effects of genotype may compare the L_A/L_A genotype against all other genotypes.^[6] The allele frequency of this polymorphism seems to vary considerably across populations, with a higher frequency of the long allele in Europe and lower frequency in Asia.^[7]

In a recent study, authors found that individuals homozygous for the long allele of 5-HTLPR paid more attention on average to positive affective pictures while selectively avoiding negative affective pictures presented alongside the positive pictures compared to their heterozygous and short-allele-homozygous peers. This biased attention of positive emotional stimuli suggests they may tend to be more optimistic.^[8] Other research indicates carriers of the short 5-HTTLPR allele have difficulty disengaging attention from emotional stimuli compared to long allele homozygotes.^[9] Another recent study using an eye tracking assessment of information processing found that short 5-HTTLPR allele carriers displayed an eye gaze bias to view positive scenes and avoid negative scenes. Long allele homozygotes viewed the emotion scenes in a more even-handed fashion.^[10] This research suggests that short 5-HTTLPR allele carriers may be more sensitive to emotional information in the environment than long allele homozygotes.

1. ↑ A. Heils, A. Teufel, S. Petri, M. Seemann, D. Bengel, U. Balling, P. Riederer & K. P. Lesch (1995). "Functional promoter and polyadenylation site mapping of the human serotonin (5-HT) transporter gene". Journal of Neural Transmission 102 (3): 247–244. doi:10.1007/BF01281159. PMID 8788073. 
2. ↑ A. Heils, A. Teufel, S. Petri, G. Stober, P. Riederer, D. Bengel & Klaus-Peter Lesch (June 1996). "Allelic variation of human serotonin transporter gene expression". Journal of Neurochemistry 66 (6): 2621–2624. doi:10.1046/j.1471-4159.1996.66062621.x. PMID 8632190. 
3. ↑ ^{3.0 3.1} J.R. Wendland, B.J. Martin, M.R. Kruse, Klaus-Peter Lesch, D.L. Murphy (2006). "Simultaneous genotyping of four functional loci of human SLC6A4, with a reappraisal of 5-HTTLPR and rs255531" (PDF). Molecular Psychiatry 274 (3): 1–3. doi:10.1038/sj.mp.4001789. PMID 16402131. http://www.psychobiologie.uni-wuerzburg.de/publications/pdf/2006-5.pdf. 
4. ↑ ^{4.0 4.1} M. Nakamura, S. Ueno, A. Sano & H. Tanabe (2000). "The human serotonin transporter gene linked polymorphism (5-HTTLPR) shows ten novel allelic variants". Molecular Psychiatry 5 (1): 32–38. doi:10.1038/sj.mp.4000698. PMID 10673766. 
5. ↑ Dennis L. Murphy & Klaus-Peter Lesch (February 2008). "Targeting the murine serotonin transporter: insights into human neurobiology". Nature Reviews Neuroscience 9 (2): 85–86. doi:10.1038/nrn2284. PMID 18209729. 
6. ↑ Nicole Praschak-Rieder, James Kennedy, Alan A. Wilson, Douglas Hussey, Anahita Boovariwala, Matthaeus Willeit, Nathalie Ginovart, Subi Tharmalingam, Mario Masellis, Sylvain Houle & Jeffrey H. Meyer (August 2007). "Novel 5-HTTLPR allele associates with higher serotonin transporter binding in putamen: a [(11)C] DASB positron emission tomography study". Biological Psychiatry 62 (4): 327–321. doi:10.1016/j.biopsych.2006.09.022. PMID 17210141. 
7. ↑ Eisenberg DTA, Hayes MG (2011). "Testing the null hypothesis: comments on “Culture-gene coevolution of individualism-collectivism and the serotonin transporter gene”". Proceedings of the Royal Society B: Biological Sciences 278 (1704): 329–332. doi:10.1098/rspb.2010.0714. 
8. ↑ E.Fox, A.Ridgewell & C.Ashwin (March 2009). "Looking on the bright side: biased attention and the human sertonin transporter gene". Proceedings of the Royal Society B 276 (1663): 1747. doi:10.1098/rspb.2008.1788. 
9. ↑ C.G.Beevers, T.T.Wells, A.J.Ellis & J.E.McGeary (2009). "Association of the Serotonin Transporter Gene Promoter Region (5-HTTLPR) Polymorphism with Biased Attention for Emotional Stimuli". Journal of Abnormal Psychology 118 (3): 670–81. doi:10.1037/a0016198. PMID 19685963. PMC 2841741. //www.ncbi.nlm.nih.gov/pmc/articles/PMC2841741/. 
10. ↑ C.G.Beevers, A.J.Ellis, T.T.Wells & J.E.McGeary (2009). "Serotonin Transporter Gene Promoter Region Polymorphism and Selective Processing of Emotional Images". Biological Psychology 83 (3): 260–5. doi:10.1016/j.biopsycho.2009.08.007. PMID 19715738. PMC 2834869. //www.ncbi.nlm.nih.gov/pmc/articles/PMC2834869/.