A systematic review of the heritability of specific psychopathic traits using Hare's two-factor model of psychopathy

Using twin-pairs to assess potential bias in polygenic prediction of externalising behaviours across development

Prediction from polygenic scores may be confounded sources of passive gene-environment correlation (rGE; e.g. population stratification, assortative mating, and environmentally mediated effects of parental genotype on child phenotype). Using genomic data from 10,000 twin pairs, we asked whether polygenic scores from the recent externalising genome-wide association study predicted conduct problems, ADHD symptomology and callous-unemotional traits, and whether these predictions are biased by rGE. We ran regression models including within-family and between-family polygenic scores, to separate the direct genetic influence on a trait from environmental influences that correlate with genes (indirect genetic effects). Findings suggested that this externalising polygenic score is a good index of direct genetic influence on conduct and ADHD-related symptoms across development, with minimal bias from rGE, although the polygenic score predicted less variance in CU traits. Post-hoc analyses showed some indirect genetic effects acting on a common factor indexing stability of conduct problems across time and contexts.

Hypothalamic-pituitary-adrenal axis responsivity during adolescence in relation to psychopathic personality traits later in life

Psychopathic personality traits have been linked to low physiological arousal, particularly among high risk and forensic samples. A core indicator of physiological arousal is the activity of the hypothalamic-pituitary-adrenal (HPA) axis; however, findings of a link between HPA axis functioning and psychopathic personality traits have been inconsistent. Furthermore, given sex differences in both HPA axis responsivity and psychopathic personality traits, the association may be expected to differ between men and women. The aim of this study was to investigate the association between HPA axis responsivity in mid-adolescence and psychopathic personality traits in early adulthood and determine whether the association was moderated by sex. We examined this link in a general population sample of twins (N = 556). Adolescents participated in a psychosocial stress task during which samples of salivary cortisol were collected (11-15 years) and reported psychopathic personality traits using the Triarchic Psychopathy Measure (19-20 years). Multilevel linear regression models were estimated in which psychopathic personality traits (boldness, meanness and disinhibition), and their interactions with sex, were regressed on HPA axis responsivity. The study was pre-registered on the Open Science Framework (osf.io/gs2a8). Preliminary analyses showed that cortisol levels did not increase significantly during the stressor task but decreased during recovery. Results showed that there was no association between HPA axis responsivity in mid-adolescence and psychopathic personality traits in early adulthood. The associations were not moderated by sex. Findings suggest that HPA axis responsivity in mid-adolescence did not serve as a biological marker for psychopathic personality traits among young adults from the general population.

Childhood Maltreatment and Adolescent Cyberbullying Perpetration: A Moderated Mediation Model of Callous-Unemotional Traits and Perceived Social Support

Although childhood maltreatment has been shown to play an important role in adolescent cyberbullying perpetration, little is known about mediating and moderating mechanisms underlying this relationship. The current study investigated the mediating role of callous-unemotional (CU) traits in the association between childhood maltreatment and adolescent cyberbullying perpetration, as well as the moderating role of perceived social support. A total of 2,407 Chinese adolescents (aged 11-16 years, M_age = 12.75 years, SD = 0.58) completed the measures of childhood maltreatment, CU traits, cyberbullying perpetration, and perceived social support. The results showed that CU traits partially mediated the relationship between childhood maltreatment and adolescent cyberbullying perpetration. Furthermore, perceived social support moderated the relationship between childhood maltreatment and CU traits, as well as CU traits and cyberbullying perpetration. Specifically, childhood maltreatment had a greater impact on CU traits for adolescents with higher levels of perceived social support and the predictive function of CU traits on cyberbullying perpetration was stronger for adolescents with low levels of perceived social support.

The relationship between childhood trauma and suicidal ideation, the mediating role of identification of all humanity, indifference and loneliness

BACKGROUND

Research shows that childhood trauma has a detrimental impact on an individual's health, including suicidal ideation. In order to intervene with suicidal ideation, it is necessary to study the impact of childhood trauma on emotional and social functioning. This study explored the relationship between childhood trauma and suicidal ideation from the perspectives of indifference, identification with all humanity, and loneliness.

METHODS

A total number of 8,452 college students completed the study. Childhood trauma was measured by the short form of Childhood Trauma Questionnaire (CTQ-SF). The Identification With All Humanity scale (IWAH) was used to measure individual's ability to identify or not identify with humanity. For indifference, we used the Inventory of Callous-Unemotional Traits, and Loneliness was assessed by the Loneliness Scale. The relationship of indifference, identification with all humanity, and loneliness were explored to further understand the relationship between childhood trauma and suicidal ideation's correlations, regression analysis, and path analysis were employed for data analysis.

RESULTS

Childhood trauma was positively correlated with indifference, loneliness, and suicidal ideation, and negatively correlated with identification with all humanity (r = -0.140∼0.335, p < .001). Suicidal ideation was positively correlated with indifference and loneliness, and negatively correlated with identification with all humanity (r = -0.082∼0.260, p < .001). The results indicated that childhood trauma leads to indifference, which increases loneliness, and results in suicidal ideation (β = 0.073∼0.335, p < 0.001). If an individual with childhood trauma were to gain more recognition from social groups, this would reduce their loneliness and suicidal ideation (β = -0.125∼0.228, p < 0.001).

DISCUSSION

Individuals with childhood trauma were more likely to display apathy, including non-emotional behavior. This makes individuals lonelier and may increase suicidal ideation. However, if individuals are further recognized by others and social groups within their environment it is possible to intervene in this process.