Department of Psychology, University of Bonn. Kaiser-Karl-Ring 9, D-53111 Bonn, Germany.
Soc Cogn Affect Neurosci. 2011 Oct;6(5):662-8. doi: 10.1093/scan/nsq083. Epub 2010 Oct 28.
Findings from twin studies yield heritability estimates of 0.50 for prosocial behaviours like empathy, cooperativeness and altruism. First molecular genetic studies underline the influence of polymorphisms located on genes coding for the receptors of the neuropeptides, oxytocin and vasopressin. However, the proportion of variance explained by these gene loci is rather low indicating that additional genetic variants must be involved. Pharmacological studies show that the dopaminergic system interacts with oxytocin and vasopressin. The present experimental study tests a dopaminergic candidate polymorphism for altruistic behaviour, the functional COMT Val158Met SNP. N = 101 healthy Caucasian subjects participated in the study. Altruism was assessed by the amount of money donated to a poor child in a developing country, after having earned money by participating in two straining computer experiments. Construct validity of the experimental data was given: the highest correlation between the amount of donations and personality was observed for cooperativeness (r = 0.32, P ≤ 0.001). Carriers of at least one Val allele donated about twice as much money as compared with those participants without a Val allele (P = 0.01). Cooperativeness and the Val allele of COMT additively explained 14.6% of the variance in donation behaviour. Results indicate that the Val allele representing strong catabolism of dopamine is related to altruism.
双胞胎研究的结果表明，同理心、合作和利他等亲社会行为的遗传率估计值为 0.50。最初的分子遗传学研究强调了位于编码神经肽催产素和血管升压素受体的基因上的多态性的影响。然而，这些基因座解释的方差比例相当低，表明必须涉及其他遗传变异。药理学研究表明，多巴胺能系统与催产素和血管升压素相互作用。本实验研究测试了利他行为的多巴胺能候选多态性，即功能性 COMT Val158Met SNP。101 名健康的白种人受试者参加了这项研究。通过参与两项艰苦的计算机实验来赚取金钱后，向发展中国家的贫困儿童捐款的金额来评估利他主义。实验数据的结构效度如下：捐赠数量与人格之间的相关性最高的是合作性（r=0.32，P≤0.001）。与没有 Val 等位基因的参与者相比，至少携带一个 Val 等位基因的人捐赠的金额大约是其两倍（P=0.01）。合作性和 COMT 的 Val 等位基因共同解释了捐赠行为 14.6%的方差。结果表明，代表多巴胺强烈分解代谢的 Val 等位基因与利他主义有关。
