Spectral Parameters of Heart Rate Variability as Indicators of the System Mismatch During Solving Moral Dilemmas

Variability in beat-to-beat heart activity reflects the dynamics of heart-brain interactions. From the positions of the system evolutionary theory, any behaviour is based on simultaneous actualization of functional systems formed at different stages of phylo- and ontogenesis. Each functional system is comprised by neurons and other body cells, the activity of which contributes to achieving an adaptive outcome for the whole organism. In this study we hypothesized that the dynamics of spectral parameters of heart rate variability (HRV) can be used as an indicator of the system mismatch observed when functional systems with contradictory characteristics are actualized simultaneously. We presented 4–11-year-old children (N = 34) with a set of moral dilemmas describing situations where an in-group member achieved optional benefits by acting unfairly and endangering lives of out-group members. The results showed that LF/HF ratio of HRV was higher in children with developed moral attitudes for fairness toward out-groups as compared to children who showed preference for in-group members despite the unfair outcome for the out-group. Thus, the system mismatch in situations with a moral conflict is shown to be reflected in the dynamics of heart activity.