The effect of the serotonin transporter polymorphism (5-HTTLPR) on empathic and self-conscious emotional reactivity

Abstract

We examined the relationship between a functional polymorphism of the serotonin transporter gene (5-HTTLPR) and individual differences in emotional reactivity in two laboratory studies. In Study 1, empathic responding and physiological reactivity to viewing films of others in distress were assessed in healthy adults in three age groups. In Study 2, emotional responding to watching oneself in an embarrassing situation was assessed in healthy adults and in patients with neurodegenerative diseases. In Study 1, participants with two short alleles of 5-HTTLPR reported more personal distress and showed higher levels of physiological responses in response to the films than participants with long alleles. In Study 2, participants with two short alleles reported more anger and amusement and displayed more emotional expressive behaviors in response to the embarrassing situation than participants with long alleles. These two findings from diverse samples of participants converge to indicate that individuals who are homozygous for the short allele variant of 5-HTTLPR have greater levels of emotional reactivity in two quite different socially embedded contexts.

Figure 1

Study 1: 5-HTTLPR and self-reported empathic concern and personal distress in response to films of others in distress. There are no differences in empathic concern, but the SS variant differs from the SL/LL variant on personal distress. Note. Estimated marginal means (controlled for covariates). Error bars represent standard errors of the mean.* p < .05

Figure 2

Study 1: 5-HTTLPR and physiological responding to films of others in distress. The SS variant differs from the SL/LL variants and shows the highest levels of reactivity. Note. Estimated marginal means (controlled for covariates). Error bars represent standard errors of the mean. * p < .05

Figure 3

Study 2: 5-HTTLPR and specific emotional experiences of anger and amusement when watching oneself in an embarrassing situation. The SS variant differs from the SL/LL variants on anger and from the LL variant on amusement. Note. Estimated marginal means (controlled for covariates). Error bars represent standard errors of the mean. * p < .05

Figure 4

Study 2: 5-HTTLPR and total emotional expressive behavior (sum of all emotions across the coded 30 seconds weighted by intensity) when watching oneself in an embarrassing situation. The SS variant differs from the SL/LL variants. Note. Estimated marginal means (controlled for covariates). Error bars represent standard errors of the mean. * p < .05