Psychopathic personality traits in 5 year old twins: the importance of genetic and shared environmental influences

Elucidating the role of negative parenting in the genetic v. environmental influences on adult psychopathic traits

BACKGROUND

Psychopathic traits involve interpersonal manipulation, callous affect, erratic lifestyle, and antisocial behavior. Though adult psychopathic traits emerge from both genetic and environmental risk, no studies have examined etiologic associations between adult psychopathic traits and experiences of parenting in childhood, or the extent to which parenting practices may impact the heritability of adult psychopathic traits using a genetically-informed design.

METHODS

In total, 1842 adult twins from the community reported their current psychopathic traits and experiences of negative parenting during childhood. We fit bivariate genetic models to the data, decomposing the variance within, and the covariance between, psychopathic traits and perceived negative parenting into their genetic and environmental components. We then fit a genotype × environment interaction model to evaluate whether negative parenting moderated the etiology of psychopathic traits.

RESULTS

Psychopathic traits were moderately heritable with substantial non-shared environmental influences. There were significant associations between perceived negative parenting and three of four psychopathy facets (interpersonal manipulation, erratic lifestyle, antisocial tendencies, but not callous affect). These associations were attributable to a common non-shared environmental pathway and not to overlapping genetic effects. Additionally, we found that primarily shared environmental influences were stronger on psychopathic traits for individuals with a history of greater negative parenting.

CONCLUSIONS

Utilizing a genetically-informed design, we found that both genetic and non-shared environmental factors contribute to the emergence of psychopathic traits. Moreover, perceptions of negative parenting emerged as a clear environmental influence on the development of interpersonal, lifestyle, and antisocial features of psychopathy.

HTR1B genotype and psychopathy: Main effect and interaction with paternal maltreatment

Psychopathy is a condition characterized by atypical emotions and socially maladaptive behavioral patterns. Among incarcerated people, psychopathy has been associated with higher rates of crimes, recidivism, and resistance to treatment. Many studies have indicated significant heritability of psychopathic traits, but little is known about the specific contribution of genes and their interaction with adverse experiences in life. Considering the primary role that serotonin plays in cognition and emotion, we investigated TPH2-rs4570625, 5-HTTLPR, MAOA-uVNTR, HTR1B-rs13212041 and HTR2A-rs6314 as risk factors for psychopathy in the largest sample of institutionalized individuals studied so far, consisting of 793 US White male incarcerated adults, and in a replication sample of 168 US White male incarcerated adolescents. In a subgroup of the adult sample, the interaction between genetics and parenting style, assessed by the Measure of Parental Style (MOPS) questionnaire, was also evaluated. The HTR1B-rs13212041-T/T genotype, as compared to HTR1B-rs13212041-C allele, predicted higher psychopathy scores in both the adult and the adolescent samples. The interaction between HTR1B-rs13212041-T/T genotype and paternal MOPS scores, investigated in a subgroup of the adult sample, was an even stronger predictor of higher levels of psychopathy than either the genetics or the environment taken individually. Overall, these data, obtained in two independent samples, shed new light on neurobiological correlates of psychopathy with promising implications both at a clinical and forensic level.

Exploring psychopathy traits on intertemporal decision-making, neurophysiological correlates, and emotions on time estimation in community adults

There are certain characteristics of psychopathy that may be related to changes in intertemporal choices. Specifically, traits such as impulsivity or lack of inhibitory control may be associated with a more pronounced discounting function in intertemporal choices (IC) and, in turn, this function may be based on changes in the basic mechanisms of time estimation (TE). Therefore, this study aimed to examine potential differences in neurophysiological correlates, specifically through N1, P3, and LPP measurements, which may be related to TE and IC, examining their modulation according to psychopathic traits, different emotional conditions, and different decision-making conditions. This experimental study included 67 adult participants (48 women) from the northern region of Portugal, who performed an intertemporal decision-making task and, of those, 19 participants (16 women), with a mean age of 25 years (SD = 5.41) and a mean of 16 years of schooling (SD = 3.37) performed the time estimation task. The instruments/measures applied were MoCA, used as a neurocognitive screening tool; the Triarchic Psychopathy Measure (TriPM), a self-report instrument with 58 items that map the core features of psychopathy along three facets – boldness, meanness, and disinhibition – and considers them continuously distributed among the general population; intertemporal decision-making and time estimation tasks – for the time estimation task, the stimuli consisted of 45 color images extracted from the Nencki Affective Picture System (NAPS). In the TE task, there was an almost significant effect of disinhibition on the values of θ, with higher values on this variable associated with greater values of θ in the unpleasant emotional condition. In the IC task, there were no significant effects of any psychopathy measure on the values of the gains and losses ratios. In addition, the analysis of the neurophysiological correlates of the IC task did not reveal a main effect of the decision-making condition, nor effects of any psychopathy measure on the N1 and P3 amplitudes. The analysis of the neurophysiological correlates of the TE task revealed that higher meanness values are associated with smaller N1 amplitude in the pleasant emotional condition, whereas higher disinhibition values are associated with greater N1 amplitude in the pleasant emotional condition. Still in this task, higher disinhibition values were associated with a smaller LPP amplitude in the unpleasant emotional condition. The increase in the distribution of attention resources towards time and/or the increase in activation states, including those originated by responses to emotional stimuli, may be the main factor that alters the way impulsive individuals and, presumably, individuals with high psychopathy, consider time when making decisions.

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There are certain characteristics of psychopathy that may be related to changes in IC.

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Higher meanness values are associated with smaller N1 amplitude in the pleasant emotional condition (TE task).

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Higher disinhibition values are associated with greater N1 amplitude in the pleasant emotional condition (TE task).

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Higher disinhibition values were associated with a smaller LPP amplitude in the unpleasant emotional condition (TE task).

Studying Configurations of Psychopathic Traits: Exploring the Viability of Psychopathic Personality in Early Childhood

The idea that very young children can manifest a constellation of personality traits that looks like psychopathy has rarely been explored. To fill this void, data from 2,247 children, aged 3-6 years (M = 4.25; SD = 0.91), from the Estudio Longitudinal para una Infancia Saludable (ELISA) were utilized. Parents and teachers completed questionnaires at baseline and at 1-year follow-up. Using three parent-rated psychopathy dimensions as indicators, the authors conducted latent profile analysis and arrived at five latent classes: Control (39.2%), Impulsive-Need for Stimulation (34.8%), Grandiose-Deceitful (16.5%), Callous-Unemotional (6.2%), and Putative Psychopathic Personality (PP, 3.3%). Children in the PP class, overall, engaged in higher levels of concurrent, future, and stable conduct problems and reactive and proactive aggression, and lower levels of prosocial behavior, as rated by parents or teachers. Findings also revealed meaningful differences between the remaining four classes. Person-oriented analyses seem to offer a fruitful avenue to identify 3-to 6-year-olds who exhibit a putative psychopathic personality and are at risk for future maladjustment.

Selfish parents, parenting practices, and psychopathic traits in children

Parental personality and parenting behavior have been associated with the development of psychopathic traits in offspring. However, no study has examined the effect of parental dispositional selfishness on the development of psychopathic traits in offspring, and the potential mechanism underlying this relationship. To address this issue, parents' reports on their dispositional selfishness, negative and positive parenting behavior, and child's psychopathic traits were collected for a group of children from the community (n = 118, 47% male, mean age = 14.1 years). Results showed that parental selfishness was associated with grandiose-manipulative (GM), daring-impulsive (DI), and callous-unemotional (CU) traits in children. In addition, the egocentric selfishness-GM relationship was indirectly mediated by parenting behavior including lack of involvement, poor monitoring, and inconsistent discipline, whereas the association with CU traits was directly mediated by lack of involvement. These effects remained significant after controlling for child's sex, age, race, social adversity, and a prior measure of psychopathic traits. Findings provide initial empirical evidence on the effect of parental selfishness on a child's psychopathic traits, and further support to the proposition that distinct etiology may underlie different dimensions of psychopathic traits.

Parental positive regard and expressed emotion-prediction of developing attention deficit, oppositional and callous unemotional problems between preschool and school age

Parental expressed emotion and positive reinforcement are assumed to affect the development of oppositional and callous-unemotional behaviors in children at risk of attention deficit hyperactivity disorder (ADHD). As longitudinal research on this issue is scarce, we analyzed the respective links between preschool and school age. 138 five-year-old (m = 58.2, s = 6.2 months) children (59% boys) with elevated ADHD symptoms (according to screening) were assessed at the ages of five and eight years. At 5 years, maternal expressed emotion (using the Five Minute Speech Sample) and positive regard of child (using a standardized at-home observation procedure) were assessed. At 5 and 8 years, symptoms of ADHD, oppositional defiant disorder (ODD), and callous-unemotional (CU) behaviors were measured using a multi-informant approach. Multiple linear regression analyses revealed that positive regard specifically predicted a decrease in ODD symptoms between preschool and school age. The expression of high negative emotion specifically predicted an increase in CU behaviors. The development of ADHD symptoms was not predicted by parenting. Knowledge on these specific links can help to elaborate diagnostic and counseling processes in preschoolers with high ADHD symptoms. Underlying mechanisms and the role of neurocognitive deficits of the preschool child should be further analyzed.

Genetic and environmental influences on disinhibition, boldness, and meanness as assessed by the triarchic psychopathy measure in 19-20-year-old twins

BACKGROUND

The Triarchic Psychopathy Measure (TriPM) provides Disinhibition, Boldness, and Meanness scales for assessing the three trait domains of the triarchic model. Here we examined the genetic and environmental etiology of these three domains, including evaluation of potential sex differences.

METHODS

A total of 1016 men and women ages 19-20 years were drawn from the University of Southern California Risk Factors for Antisocial Behavior twin study.

RESULTS

Scores for the three TriPM scales were correlated to differing degrees, with the strongest phenotypic correlation between Disinhibition and Meanness. No sex differences were found in the genetic and environmental influences underlying these three domains, suggesting that the same genes and life experiences contribute to these traits in young men and women. For TriPM Disinhibition and Boldness, genetic factors explained about half or less of the variance, with the rest of the variance being explained by non-shared environmental factors. For TriPM Meanness, on the other hand, genetic, shared environmental, and non-shared environmental factors accounted for the variance. The phenotypic correlation between Disinhibition and Meanness was explained in part by common genes (26%), with the remainder attributable about equally to common shared (39%), and non-shared environmental influences (35%).

CONCLUSIONS

These findings contribute to our understanding of psychopathic personality traits by demonstrating the importance of heritable factors for disinhibition and boldness facets of psychopathy, and the importance of shared environmental influences for the meanness facet.

The genetic underpinnings of callous-unemotional traits: A systematic research review

BACKGROUND

Callous-unemotional (CU) traits represent the affective features of psychopathy used to delineate youth at high risk for externalizing pathology. The genetic etiology CU traits is not currently well-understood.

METHODS

The current review surveyed the literature for studies on the genetic underpinnings of CU traits and integrated information from 39 genetic studies.

RESULTS

The results from 24 studies with quantitative data suggest that the heritability for CU traits is likely between 36-67%. A majority of the 16 molecular genetic studies focused on candidate genes in the serotonin and oxytocin systems with results that have not been well replicated. Although two genome-wide association studies have been conducted, no genome-wide significant loci have been discovered.

DISCUSSION

There is some evidence to suggest that the serotonin and oxytocin systems may play a role in CU traits; however, there is currently not enough evidence to implicate specific genetic mechanisms. The authors encourage researchers to continue to apply the most up-to-date and relevant methodology, specifically collaborations and consortiums using genome-wide and polygenic methods.

Main and interaction effects of childhood trauma and the MAOA uVNTR polymorphism on psychopathy

Psychopathy is characterized by callous affect, interpersonal manipulation, a deviant lifestyle, and antisocial behavior. Previous research has linked psychopathic traits to childhood trauma, but also to the upstream variable number tandem repeat (uVNTR) polymorphism of the monoamine oxidase A (MAOA) gene. An interaction between childhood trauma and MAOA genotype has been associated with antisocial behavior, but so far little is known about interaction effects of childhood trauma and the MAOA uVNTR on psychopathy. In order to bridge this gap, we used data of 1531 male and 1265 female twins and their siblings from a Finnish community sample to estimate structural equation models. The psychopathy and childhood trauma constructs were conceptualized as bifactor models with one general and two orthogonal group factors. Data comprised self-reports on childhood trauma and psychopathic traits as well as MAOA uVNTR genotype. In both genders, childhood trauma was associated with the general factor that represents the overarching psychopathy construct, and with the group factor that captures social deviance, but not with the group factor capturing psychopathic core personality traits. Women with a low activity variant of the MAOA uVNTR reported slightly higher levels of psychopathy than those with a high activity allele, but only with respect to the general psychopathy factor. There was no evidence for an interaction effect between MAOA uVNTR genotype and childhood trauma on psychopathy in either gender. Our results suggest that psychopathy in general and social deviance in particular are associated with childhood trauma in men and women, and that psychopathic traits are subject to variation in the MAOA uVNTR genotype in women.

Understanding the development of psychopathy: progress and challenges

Psychopathy is an adult condition that incurs substantial societal and individual costs. Here we review neurocognitive and genetically informative studies that shed light on how and why this condition emerges. Children cannot present with psychopathy. However, the presence of callous-unemotional (CU) traits can distinguish a group of children who are at elevated risk of psychopathy in adulthood. These children display diminished empathy and guilt and show attenuated brain activation to distress cues in others. Genetically informative studies indicate that individual differences in CU traits show moderate-to-strong heritability, but that protective environmental factors can counter heritable risk. On the basis of the extant research findings, we speculate on what might represent the priorities for research over the next decade. We also consider the clinical implications of these research findings. In particular, we consider the importance of delineating what precisely works for children with CU traits (and their parents) and the ways in which intervention and prevention programs may be optimized to improve engagement as well as clinical outcomes.

Conduct disorders and psychopathy in children and adolescents: aetiology, clinical presentation and treatment strategies of callous-unemotional traits

Conduct Disorder (CD) is a psychiatric diagnosis characterized by a repetitive and persistent pattern of behaviour in which the basic rights of others and major age-appropriate social norms or rules are violated. Callous Unemotional (CU) traits are a meaningful specifier in subtyping CD for more severe antisocial and aggressive behaviours in adult psychopathology; they represent the affective dimension of adult psychopathy, but they can be also detected in childhood and adolescence. The CU traits include lack of empathy, sense of guilt and shallow emotion, and their characterization in youth can improve our diagnostic, prognostic and therapeutic abilities. A strong genetic liability, in interaction with parenting and relevant environmental factors, can lead to elevated levels of CU traits in children. We pointed out that CU traits can be detected in early childhood, may remain stable along the adolescence, but a decrease following intensive and specialized treatment is possible. We here provide a narrative review of the available evidences on CU traits in three main domains: aetiology (encompassing genetic liability and environmental risk factors), presentation (early signs and longitudinal trajectories) and treatments.