Adventurous and antisocial hearts: Investigating the causality of associations between antisocial behaviour, resting heart rate and sensation seeking

Antisocial behaviour (ASB) is associated with negative outcomes later in life, such as criminal behaviour. Prior research found resting heart rate (RHR) to be one of the most robust physiological correlates of ASB, where a lower RHR was associated with higher levels of ASB. This relationship could be mediated by sensation seeking (SS), where SS could result from a lack of inhibition, marked by a low RHR, or could be employed to raise the heart rate to a more comfortable level of arousal. However, there is currently little proof that the relationships between ASB, RHR, and SS are causal. This study therefore used multilevel mixed effects models including between- and within-family effects to study the relationships between ASB, RHR, and SS. Relationships were first investigated in a broad sample (N = 8422), then in a subsample of dizygotic (DZ) twins (N = 1927), and finally, the relationship between SS and ASB was investigated in a subsample of monozygotic (MZ) twins (N = 2599). Polygenic scores for RHR, used as a proxy for RHR, only predicted ASB between families in the broad sample, without mediation of SS. RHR was not associated with ASB in the DZ sample. Conversely, SS significantly predicted ASB in the broad sample. Additionally, the between- and within-family effect of SS significantly predicted ASB in the DZ and MZ sample, which is consistent with a potential causal relationship. SS could therefore be an effective target for ASB interventions, regardless of RHR.