The heart as judge: Association of heart rate variability with moral judgement-A replication study.

There is growing research into contributing processes and biological correlates of moral inclinations. Recently, a negative association between utilitarianism and resting heart rate variability (HRV) as an indicator of cardiac vagal tone/parasympathetic activity was reported. We aimed to replicate and extend these findings by additionally investigating the sympathetic parameter electro-dermal activity (EDA), but found no associations in the total sample (N = 157). However, when taking sex and the use of combined oral contraceptives (COC) into account, we found a positive association between HRV and estimated deontology in women using COC and men, while in free cycling women there was a negative association. While no direct replication, our results also point to associations between higher HRV and decreased endorsement of harmful actions that serve a greater good. Unlike HRV, EDA showed no associations with moral judgements. In addition, there were correlations between personality traits and moral judgement.