Serotonin Transporter Genotype (5-HTTLPR) Predicts Utilitarian Moral Judgments

Abstract

BackgroundThe psychological and neurobiological processes underlying moral judgment have been the focus of extensive recent research. Here we show that serotonin transporter (5-HTTLPR) genotype predicts responses to moral dilemmas featuring foreseen harm to an innocent.Methodology/Principal FindingsParticipants in this study judged the acceptability of actions that would unintentionally or intentionally harm an innocent victim in order to save others' lives. An analysis of variance revealed a genotype × scenario interaction, F(2, 63) = 4.52, p = .02. Results showed that, relative to long allele homozygotes (LL), carriers of the short (S) allele showed particular reluctance to endorse utilitarian actions resulting in foreseen harm to an innocent individual. LL genotype participants rated perpetrating unintentional harm as more acceptable (M = 4.98, SEM = 0.20) than did SL genotype participants (M = 4.65, SEM = 0.20) or SS genotype participants (M = 4.29, SEM = 0.30). No group differences in moral judgments were observed in response to scenarios featuring intentional harm.Conclusions/SignificanceThe results indicate that inherited variants in a genetic polymorphism that influences serotonin neurotransmission influence utilitarian moral judgments as well. This finding is interpreted in light of evidence that the S allele is associated with elevated emotional responsiveness.

Personality and Blood Types Revisited: Case of Morality

“…Our results show that only the ability to empathise and to desire purity [27] are innate in each living human being (probably in part determined by genetics), and represents our "first draft" of the moral mind. These results partially follow Haidt's theory (innateness of all moral 5 Analysis of variance (ANOVA) is a collection of statistical models used to analyse the differences between group means and their associated procedures (such as "variation" among and between groups), developed by R.A. Fisher. In the ANOVA setting, the observed variance in a particular variable is partitioned into components attributable to different sources of variation.…”

“…Based on the data obtained, we can conclude that there is a connection between the moral foundations of Harm [5] and Purity and blood group. Our post hoc tests show that this is the case with B, O and AB blood types, when speaking about Harm.…”

“…According to Marsh [5], there is a link between a genetic polymorphism which influences serotonin neurotransmission and utilitarian moral judgments (causing harm to others), as well. This finding is interpreted in light of evidence that the S allele is associated with elevated emotional responsiveness.…”

Theory of mind, empathy and moral emotions in patients with affective disorders

“…In the long run, persons with the "worse" combination of alleles may have increased risk of developing depression, by a lower resistance to stressful events. What is important, authors of some of the recent research found that polymorphism 5-HT-TLPR gene not only modulates mood, but it can also affect -to some extent -the process of moral decision-making [38,41 ], therefore it significantly influences our social functioning. Interestingly, serotonin (neurotransmitter, the operation of which is encoded by described gene) seems to play an important role in the regulation of social behavior of different species, not just of people [38].…”

Molecular genetics and antisocial behavior: Where do we stand?

“…67 A preliminary study on the genetics of moral behavior found an association between the S allele of 5HTTLPR and moral judgment, as the S carriers rated ''unintentional harm'' less acceptable than L-L individuals. 68 Several studies have described an association between the S allele of 5HTTLPR and impulsivity, aggression, and conduct disorders, 8,[69][70][71][72][73] while other studies, including a recent meta-analysis, reported non-replications of these data. [74][75][76] Contrariwise, an association of the long form of 5HTTLPR to the same behavioral traits has been published.…”