Low resting heart rate, sensation seeking and the course of antisocial behaviour across adolescence and young adulthood

Resting heart rate and antisocial behaviour: a Mendelian randomisation study

Observational studies frequently report phenotypic associations between low resting heart rate (RHR) and higher levels of antisocial behaviour (ASB), although it remains unclear whether this relationship reflects causality. To triangulate evidence, we conducted two-sample univariable Mendelian randomisation (MR), multivariable MR and linkage disequilibrium score regression (LDSC) analyses. Genetic data were accessed from published genome-wide association studies (GWAS) for RHR (n = 458,835) and ASB (n = 85,359) for the univariable analyses, along with a third GWAS for heart rate variability (HRV; n = 53,174) for all other analyses. Genome-wide significant (p < 5 × 10-8) single-nucleotide polymorphisms associated with RHR (n = 278) were selected as instrumental variables and the outcome was a composite measure of ASB. No causal association was observed between RHR and ASB (BIVW =  - 0.0004, p = 0.841). The multivariable MR analyses including RHR and HRV also suggested no causal associations (BIVW = 0.016, p = 0.914) and no genetic correlations between the heart rate measures and ASB were observed using LDSC (rg = 0.057, p = 0.169). Sensitivity analyses suggested that our results are not likely to be affected by heterogeneity, pleiotropic effects, or reverse causation. These findings suggest that individual differences in autonomic nervous system functioning indexed by RHR are not likely to directly contribute to the development of ASB. Therefore, previously observed associations between RHR and ASB may arise from confounding, reverse causation, and/or additional study characteristics. Further causally informative longitudinal research is required to confirm our findings, and caution should be applied when using measures of RHR in interventions targeting ASB.

Autonomic Arousal, Ethical Guilt, and Externalizing Behavior in Childhood: A Clinical Extension and Replication

Lower autonomic arousal is associated with higher externalizing behavior in childhood but the mechanisms explaining this link are still debated. One possibility is that lower autonomic arousal makes it difficult for children to anticipate or express social emotions, such as ethical guilt rooted in concern for others, thereby increasing their likelihood of externalizing behavior. However, evidence for this social-emotional hypothesis has been limited to community samples. The present study included ethnically diverse samples of 150 typically developing children (M_age = 8.01 years; 50% girls) and 62 children referred for clinically elevated externalizing behavior (M_age = 9.16 years; 16% girls; N = 212). Caregivers reported children's externalizing behavior. Children's respiratory sinus arrhythmia (RSA) was measured as an indicator of parasympathetic activity in response to hypothetical vignettes depicting externalizing behavior. Children's ethical guilt was coded from semi-structured interviews following each vignette. Greater RSA increases (indicating a low-arousal, rest-and-digest response) were associated with lower ethical guilt. Lower ethical guilt was associated with higher externalizing behavior. A significant indirect effect showed that RSA increases were associated with higher externalizing behavior through relative lapses in ethical guilt. Results were consistent across and within the community and clinical samples. Theoretical and practical implications for clinically elevated externalizing behavior are discussed.

Sensation-seeking-related DNA methylation and the development of delinquency: A longitudinal epigenome-wide study

Heightened sensation-seeking is related to the development of delinquency. Moreover, sensation-seeking, or biological correlates of sensation-seeking, are suggested as factors linking victimization to delinquency. Here, we focused on epigenetic correlates of sensation-seeking. First, we identified DNA methylation (DNAm) patterns related to sensation-seeking. Second, we investigated the association between sensation-seeking related DNAm and the development of delinquency. Third, we examined whether victimization was related to sensation-seeking related DNAm and the development of delinquency. Participants (N = 905; 49% boys) came from the Avon Longitudinal Study of Parents and Children. DNAm was assessed at birth, age 7 and age 15-17. Sensation-seeking (self-reports) was assessed at age 11 and 14. Delinquency (self-reports) was assessed at age 17-19. Sensation-seeking epigenome-wide association study revealed that no probes reached the critical significance level. However, 20 differential methylated probes reached marginal significance. With these 20 suggestive sites, a sensation-seeking cumulative DNAm risk score was created. Results showed that this DNAm risk score at age 15-17 was related to delinquency at age 17-19. Moreover, an indirect effect of victimization to delinquency via DNAm was found. Sensation-seeking related DNAm is a potential biological correlate that can help to understand the development of delinquency, including how victimization might be associated with adolescent delinquency.

Heart-wired to be cold? Exploring cardiac markers of callous-unemotional traits in incarcerated offenders

Elevated callous-unemotional (CU) traits have been repeatedly identified in a subgroup of offenders that displays severe antisocial behavior; establishing physiological markers may help improve early identification and treatment efforts. This study examines to what extent baseline-resting heart rate (HR) and heart rate variability (HRV) can be used as markers of CU in incarcerated juvenile and adult offenders. CU traits were assessed using the Inventory of Callous-Unemotional traits. Results of the multiple hierarchical regression tests indicated that there was a small yet significant positive association between baseline HR and CU and negative association between HRV and CU in juvenile offenders with medium model effect sizes (R² = 0.115 for HR-CU; R² = 0.126 for HRV-CU). The cardiac markers were unrelated to CU in adult offenders. These findings are important because they demonstrate that impaired cardiac autonomic activity is related to CU traits in juveniles, suggesting that socioemotional processing difficulties should be considered in understanding these deficits. Future research should be conducted in large samples, under reactive and static conditions, while including cardiac covariates, to get more clarity on the interplay between biological systems and behavioral expression.

The causal nature of the association between resting pulse in late adolescence and risk for internalizing and externalizing disorders: a co-relative analysis in a national male Swedish sample

BACKGROUND

Resting pulse is robustly and inversely associated with the risk for externalizing disorders and may be positively associated with internalizing disorders. We know little about the causal nature of these associations.

METHODS

We examined resting pulse at conscription examination in 369 301 males born 1960-80 with a mean (s.d.) follow-up of 29.1 (7.7) years. From pulse rates, we predicted, using Cox models, the risk for criminal behavior (CB), drug abuse (DA), alcohol use disorder (AUD), major depression (MD), and anxiety disorders (AD), assessed from medical, criminal, and pharmacy registries. Co-relative analyses were conducted on the general population, cousin, half-sibling, full-sibling, and monozygotic pairs discordant for the outcome. Twin/sibling modeling for pulse was performed using OpenMX.

RESULTS

Familial resemblance for pulse resulted entirely from genetic factors. In the general population, the risk for externalizing disorders (CB, DA, and AUD) and internalizing disorders (MD and AD) were, respectively, significantly associated with low and high resting pulse rate. For CB, DA, and AUD, co-relative analyses showed that the inverse association with pulse resulted entirely from familial common causes (aka 'confounders'). By contrast, co-relative analyses found that the association between higher pulse and MD and AD resulted from direct causal effects.

CONCLUSIONS

Resting pulse has a negative and positive association with, respectively, the risk for externalizing and for internalizing disorders. Co-relative analyses indicate that the nature of these associations differ, suggesting that elevated pulse appears to directly increase the risk for internalizing disorders while the reduced pulse is a risk index for underlying traits that predispose to externalizing disorders.

Resting Heart Rate Mediates the Relationship between Parenting Style and Callous-Unemotional Traits in Chinese Children

Despite increasing knowledge of social and biological risk factors for callous-unemotional (CU) traits, relatively less is known about how these two sets of risk factors combine to affect these traits. The current longitudinal study investigated pathways from parenting style to CU traits via resting heart rate in a three-year project. Parents of 382 children completed the Parenting Styles and Dimensions Questionnaire at Time 1 (children Mean age = 9.06, SD = 0.94, range = 7-11 years), with the heart rate data collected at Time 2 (M = 10.16, SD = 0.93, range = 8-13 years) and CU traits assessed at Time 3 (M = 11.06, SD = 0.94, range = 9-13 years). We found that parenting style and CU traits were associated with resting heart rate, and that structural equation modeling showed resting heart rate to partially mediate the effect of parenting style on CU traits. Specifically, higher levels of authoritarian parenting were associated with lower resting heart rate, which in turn was linked to higher level of CU traits. On the contrary, children in the context of authoritative parenting showed relatively higher resting heart rate, which was predictive of lower CU traits. Overall, findings have implications for understanding the etiology of CU traits in children and developing effective prevention programs for children with affective deficits.

Sensation seeking and its relationship with psychopathic traits, impulsivity and aggression: a validation of the Dutch Brief Sensation Seeking Scale (BSSS)

Sensation seeking is a personality trait that manifests as a preference for change, variety and novelty. Sensation seeking has been positively associated with different externalising behaviours. However, its associations with psychopathic traits, impulsivity and aggression are unclear. These associations were examined via the psychometric properties of the Dutch version of the Brief Sensation Seeking Scale (BSSS) using individuals from the general population and forensic patients. The results show that the BSSS has good psychometric properties, including test-retest reliability and a four-factor structure. Additionally, the results support associations between sensation seeking and psychopathic traits, impulsivity and total scores of aggression but revealed no specific associations with different types of aggression (e.g. proactive and reactive). The Dutch BSSS is a valuable tool for assessing sensation seeking in both the general population and forensic patients. Future research should further examine its utility and explore the role of sensation seeking in antisocial conduct.

The relationship between resting heart rate and aggression in males is racially variant

Although resting heart rate is thought to be a generalizable risk factor for aggression, very little research has examined whether this relationship varies by race. We addressed this limitation using longitudinal data from the Pittsburgh Youth Study. Current data are from 197 men who participated in a teenage biosocial study (mean age = 15.7 years) and adult follow-up study (mean age = 32.1 years). Teenage resting heart rate interacted with race to predict teenage and adult aggression. The relationship between heart rate and aggression was significant in White, but not in Black males. To our knowledge, this is the first study to find that the relationship between resting heart rate and aggression is racially variant, suggesting that resting heart rate may not be a generalizable biomarker for conduct problems. At an intervention-level, findings could contribute to the development of more accurate risk assessment tools that take into account racial variance in risk factors.

Resting Heart Rate and Psychopathy Revisited: Findings From the Add Health Survey

Despite the prior linkages of low resting heart rate to antisocial behavior broadly defined, less work has been done examining possible associations between heart rate to psychopathic traits. The small body of research on the topic that has been conducted so far seems to suggest an inverse relationship between the two constructs. A smaller number of studies has found the opposite result, however, and some of the previous studies have been limited by small sample sizes and unrepresentative samples. The current study attempts to help clarify the relationship between resting heart rate and psychopathic traits in a large, nationally representative sample (analytical N ranged from 14,173-14,220) using an alternative measure of psychopathic traits that is less focused on antisocial processes, and rooted in personality traits. No significant relationship between heart rate and psychopathic traits, or heart rate and a measure of cold-heartedness, was found. It is possible that previous findings of a link between heart rate and psychopathy have been driven by the inclusion of overt antisocial behavior in many traditional psychopathy measures. Further work is needed to confirm the associations (or lack thereof) between heart rate and the behavioral, affective, and personality trait aspects of psychopathy.