Psychopathic Traits In Adolescents Research Articles

Adolescents with Elevated Psychopathic Traits are Associated with an Increased Risk for Premature Mortality.

The mortality rate among adolescents has been steadily increasing in recent years. Researchers have previously identified forms of externalizing psychopathology measured during adolescence associated with an increased risk for premature mortality, including attention-deficit/hyperactivity disorder (ADHD), substance use disorders (SUDs), oppositional defiant disorder (ODD), and conduct disorder (CD). The current study investigated whether additional personality traits (i.e., adolescent psychopathic traits, assessed via the Hare Psychopathy Checklist: Youth Version [PCL:YV]) were also associated with premature mortality risk among maximum-security incarcerated adolescents (N = 332). During a follow-up period ranging from 10 to 14 years, premature mortality was observed in n = 33 participants (9.94%), a mortality rate nearly ten times higher than population norms. We observed that adolescents scoring the highest on PCL:YV total scores exhibited significantly higher rates of premature mortality compared to adolescents scoring lower on PCL:YV total scores via Fisher's exact tests. Additionally, through univariate Cox proportional hazard regression analyses, PCL:YV total, Factor 2 (measuring lifestyle/behavioral and antisocial/developmental psychopathic traits), Facet 1 (measuring interpersonal psychopathic traits), and Facet 3 (measuring lifestyle/behavioral psychopathic traits) scores were associated with faster time to premature mortality. In supplemental analyses performed, we observed that adolescents meeting criteria for externalizing psychopathology (i.e., ADHD, SUDs, ODD, and CD) did not exhibit higher rates of premature mortality compared to control participants. The current study therefore identifies additional maladaptive personality traits to consider in relation to premature mortality risk (i.e., psychopathic traits) among a high-risk sample of incarcerated adolescents.

Adolescent psychopathic traits and adverse environments: Associations with socially adaptive outcomes.

Researchers have suggested that psychopathic traits among adults may be, at least in part, an adaptive and/or a learned response for securing socially adaptive outcomes in adverse environments, but there is a lack of developmental evidence supporting this hypothesis among adolescents. Therefore, we examined the indirect links from self-perceived adverse environments (parental neglect, socioeconomic status, school competition, neighborhood violence) to evolutionarily relevant social outcomes (social power, dating behavior) through psychopathic traits. A community sample of 396 adolescents completed measures for the study (Mage = 14.64, SD = 1.52). As predicted, there were significant indirect effects from higher levels of parental neglect, school competition, and neighborhood violence to both forms of socially adaptive outcomes through psychopathic traits, but unexpectedly, there were no indirect effects with socioeconomic status. There were also direct effects between environment and socially adaptive outcomes. Results support the hypothesis that psychopathic traits may be, in part, an adaptive and/or learned response to cues from adverse social environments as a means to acquire evolutionarily relevant social outcomes. Interventions could be designed to target the adverse social issues that might be facilitating the development of psychopathy and should be sensitive to the social outcomes adolescents may acquire from these traits.

Adolescent Psychopathic Traits, Early Adversity, and Intimate Partner Violence

Research shows psychopathic traits in adults are associated with perpetrating intimate partner violence (IPV). Less research, however, has examined this association in adolescents’ relationships. Our study examines whether adolescent psychopathic traits are associated with different forms of IPV and whether early adverse experiences of abuse and/or interparental violence might be implicated in this relationship. A mixed sample of 156 justice-involved and at-risk adolescents were assessed with the PCL:YV, participated in an early adversity interview assessing abuse and interparental violence, and completed IPV measures of physical and psychological aggressive acts. Psychopathic traits were associated with each IPV measure over and above early adversity. Psychopathic traits continued to be associated with psychological but not physical IPV after accounting for sample type. Furthermore, psychopathic traits indirectly linked interparental violence with psychological IPV, suggesting that psychopathic traits may play a role in the intergenerational perpetration of partner violence.

Stability of self-reported psychopathic traits in at-risk adolescents in youth welfare and juvenile justice institutions

BackgroundThe purpose of this study was to evaluate the self-reported stability of psychopathic traits in adolescents in residential care (both child welfare and juvenile justice placed juveniles) and potential influencing factors.MethodsWe applied the Youth Psychopathic traits Inventory (YPI) in a sample of 162 adolescents (M = 15.0 years, SD = 1.3) over a mean time interval of 11 months (min. 6, max. 21 months, SD = 3.14).ResultsThere was no significant difference in YPI total score nor in the three underlying dimensions Grandiose-Manipulative (GM), Callous-Unemotional (CU), and Impulsive-Irresponsible (II) between t1 and t2. Furthermore, approximately 70% of the adolescents showed no clinically significant reliable change on the YPI total score (as measured with the reliable change index), 15% improved, 15% deteriorated. The strongest predictor for psychopathic traits at t2 were psychopathic traits at t1. Additional predictors for higher levels of general psychopathic traits was male sex, for CU-traits male sex and lower levels of internalizing mental health problems, and for II-traits higher levels of externalizing mental health problems. Generally, the three reliable change groups (increase, no change, decrease) did not seemed to differ on relevant factors.ConclusionsOur results add to the findings that psychopathic traits are relatively stable in this at-risk group over approximately a 1-year time interval. Research with a longer follow-up time and more time points is warranted to better interpret these results.

Adolescent affective psychopathic traits: the long-term outcomes of mother-infant attachment across 14years.

Affective psychopathic traits have been associated with increased violence and aggression. The scholarly interest in the pathways leading to affective psychopathic traits in adolescence has been growing. Infant attachment security may be one of the early life factors that contribute to the development of affective psychopathic traits. In this study, we test the infant attachment styles measured with the Strange Situation Procedure as a predictor of adolescent affective psychopathic traits measured in three dimensions: remorselessness, unemotionality, and callousness, among 1149 families in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Study of Early Child Care and Youth Development (SECCYD). Propensity scores for the four attachment styles were estimated with iterative tree-based regression models. After accounting for the potential confounding effects of demographic characteristics and child temperament with the inverse probability of treatment weighting, weighted generalized linear models revealed the association between insecure/avoidant attachment style measured one year after childbirth and higher levels of remorselessness, unemotionality, and callousness at 15years. These findings provide insights into the long-term outcomes for attachment relationships established in early life.

Disruptive Behavior Disorders and Psychopathic Traits in Adolescents: Empathy-Related Responses to Witnessing Animal Distress

Cruelty to animals is a symptom of conduct disorder and associated with psychopathic traits in childhood. One of the factors thought to contribute to animal cruelty is reduced empathy and concern for the well-being of animals. A first aim of this study was to examine empathy towards animals in distress in male adolescents with disruptive behavior disorders (DBD) and high or low psychopathic traits, and normal controls (NC). Psychopathic traits were assessed by the Antisocial Process Screening Device (APSD). Respondents were exposed to a short film clip depicting a baby bear in distress. Heart rate (HR) responses were monitored during film exposure. Afterwards, respondents were asked to report the emotions they had observed and experienced. Contrary to expectations based on research on human empathy, no group differences were found in empathy-related responses to witnessing animal distress. Both DBD groups and normal controls observed equal levels of distress in the baby bear, experienced as much empathy and sympathy, and showed similar levels of HR reduction during the most dramatic scene. Results suggest that empathy for humans does not generalize to animals, and vice versa. A second aim was to examine the associations between empathy-related responses and the broad concept of psychopathy as well as its dimensions. The relationships were different and for the most part reversed in the NC and DBD groups. Group proved to be an important moderating factor, indicating that results obtained within a sample of healthy adolescents do not generalize to adolescents with DBD, and vice versa.

Parental Warmth and Hostility and the Development of Psychopathic Behaviors: A Longitudinal Study of Young Offenders

Parental behaviors may shape levels of psychopathic traits and antisocial outcomes among youth. To better evaluate the potential causality of these associations, we used eight follow-ups from the Pathways to Desistance study of 1354 offending adolescents (14.3% female; 40.1% black) and examined whether within-individual variation in parenting over time was associated with within-individual variation in psychopathic traits and offending. Multilevel regression models were adjusted for age, gender, ethnicity, contact with parental figure, and self-reported offending. Adolescent self-reported parental warmth was associated with lower psychopathic traits, and parental hostility with higher psychopathic traits. The results indicated that the more supportive and nurturing the parent, the lower the levels of psychopathic traits, whereas the more hostile the parent, the higher the levels, respectively. In addition, self-reported offending was predicted by higher parental hostility and lower maternal warmth. In time-lagged analysis, psychopathic traits did not predict parental behaviors. In young offenders parental warmth may protect against development of psychopathic traits in adolescence, whereas parental hostility may strengthen these traits. We conclude, that parenting quality matters in adolescence. Warm parenting style at this developmental period associates with lower psychopathic features among young offenders possibly lowering the risk of further criminal activity.

Gray matter asymmetry in the orbitofrontal cortex in relation to psychopathic traits in adolescents

BackgroundStructural abnormalities in the orbitofrontal cortex (OFC) of incarcerated psychopaths have been well documented. However, the neural correlates of psychopathic traits in younger and nonclinical samples remain poorly understood. AimThe present study aimed to examine the structural brain asymmetry in the OFC in relation to dimensions of psychopathic traits in adolescents from the community. MethodIn 29 youths from the community, childhood psychopathic traits including narcissism, impulsivity, and callous-unemotional traits were assessed when they were 7- to 10 years old (Time 1), and their gray matter (GM) volumes were measured using structural Magnetic Resonance Imaging when they were 10- to 14 years old (Time 2). ResultsAfter controlling for age, sex, IQ, pubertal stage, and whole-brain volumes, callous-unemotional traits were associated with right-left asymmetry in the medial OFC (mOFC), that is, smaller right mOFC GM as compared to the left. Impulsivity was associated with left-right asymmetry in the mOFC, that is, smaller left mOFC than the right. Narcissism was not associated with any GM asymmetry measure. No significant association was found for the lateral OFC, amygdala, caudate and putamen. ConclusionThe present findings provide further support that dimensions of psychopathic traits may have distinct neurobiological correlates.

Factor Structure and Construct Validity of the Youth Psychopathic Traits Inventory and Its Shorten Version in Chinese Detained Boys.

The Youth Psychopathic Traits Inventory (YPI) was designed to assess psychopathic traits in adolescents. However, there exists limited evidence for the factor structure and psychometric properties of the YPI when used with Chinese detained juveniles. The present study aimed to examine the factor structure and construct validity of the YPI and its shortened version (YPI-S) in a sample of 607 Chinese 14- to 22-year-old detained boys (M = 17.15, SD = 1.09). Confirmatory factor analyses revealed a bifactor model which best fit the data at the subscale level for the YPI, and at the item level for the YPI-S. The internal consistency of the YPI and YPI-S scores ranged from marginal to good. Both the YPI and YPI-S total and factor scores correlated positively with the APSD, an alternative psychopathic measure, as well as with proactive and reactive aggression, and correlated negatively with affective and cognitive empathy. Overall, the YPI and YPI-S are shown to be practical and valid assessment tools to measure psychopathic traits in Chinese detained youths.

Adolescent Psychopathic Traits Negatively Relate to Hemodynamic Activity within the Basal Ganglia during Error-Related Processing.

Youth with elevated psychopathic traits exhibit a number of comparable neurocognitive deficits as adult psychopathic offenders, including error-related processing deficits. Subregions of the basal ganglia play an important, though indirect, role in error-related processing through connections with cortical areas including the anterior cingulate cortex. A number of recent structural and functional magnetic resonance imaging (s/fMRI) studies have associated basal ganglia dysfunction in youth with elevated psychopathic traits, but these studies have not examined whether dysfunction occurring within subregions of the basal ganglia help contribute to error-related processing deficits previously observed in such at-risk youth. Here, we investigated error-related processing using a response inhibition Go/NoGo fMRI experimental paradigm in a large sample of incarcerated male adolescent offenders (n = 182). In the current report, psychopathy scores (measured via the Psychopathy Checklist: Youth Version (PCL:YV)) were negatively related to hemodynamic activity within input nuclei of the basal ganglia (i.e., the caudate and nucleus accumbens), as well as intrinsic/output nuclei (i.e., the globus pallidus and substantia nigra) and related nuclei (i.e., the subthalamic nucleus) during error-related processing. This is the first evidence to suggest that error-related dysfunction previously observed in youth with elevated psychopathic traits may be related to underlying abnormalities occurring within subregions of the basal ganglia.

Psychopathic Traits in Middle Childhood: Evidence of a Hierarchical Three-Factor Structure

Although the development of psychopathy is not well understood, prior studies suggest that psychopathic traits begin to develop in childhood. Whereas research suggests consistency in the structure and correlates of psychopathic traits as assessed with clinical measures of psychopathic traits in adolescence and in adulthood, there is less agreement about the nature of psychopathic traits earlier in childhood. This study was designed to enhance understanding of the nature of psychopathic traits in youth by: 1) examining the fit of one, two, three, and four factor models of psychopathic traits during middle childhood, and 2) examining the stability of the factor structure of psychopathic traits over time through invariance testing. The participants were youth in the Quebec Longitudinal Study of Child Development (QLSCD) whose teachers provided ratings on 17 items associated with four validated dimensions of psychopathy at six (N = 605), seven (N = 747) and eight years of age (N = 686). Confirmatory factor analyses revealed that a hierarchical three-factor model of psychopathic traits, consisting of interpersonal, affective, and lifestyle/ antisocial components provided the best fit to the data at all three ages. Analyses also demonstrated strong invariance across these ages. These findings provide preliminary evidence that the internal structure for a syndrome of psychopathic traits in middle childhood is somewhat similar but slightly less differentiated than the factor structure identified during adolescence. Current findings also suggest that this internal structure is stable over a three-year period during middle childhood.

Grandiose-Manipulative, Callous-Unemotional, and Daring-Impulsive: the Prediction of Psychopathic Traits in Adolescence and their Outcomes in Adulthood

There has been much debate about how to measure psychopathic traits in adolescence. One of the main issues is whether one should focus on callous-unemotional (CU) traits alone, or CU traits in combination with Grandiose-Manipulative (GM) and Daring-Impulsive (DI) traits. The current study first investigates the extent to which youth who are high on CU traits are also high on GM and DI traits. In addition, the study investigates if being high on both CU and GM, and high on both CU and DI, identify groups that are particularly characterized by past and future impairments. To investigate this, data from the Cambridge Study in Delinquent Development (CSDD) was analyzed. The CSDD is a prospective longitudinal study of 411 English boys spanning over 50 years. The information available at age 12–14 was coded on the Antisocial Process Screening Device (APSD). Childhood risk factors were measured at age 8–10 and later life outcomes were measured at age 32. The results indicate that being high on CU in combination with DI delineates a clinically interesting group who are characterized by high childhood risk and poorer adult life outcomes. The same applied to the high CU/high GM group, but to a lesser extent.

Psychopathic Traits in Adolescence: the Importance of Examining Components in Face Processing, Voice Processing, and Emotional Skill

This study examined relations among interpersonal, affective, and impulsive-irresponsible psychopathic traits, emotional capacities, and recidivism rates in 144 detained adolescents. Emotional skill was conceptualized using a range of constructs, including face and voice processing, emotional intelligence, and self-reported cognitive and affective empathy. In addition, the relation between these concepts and recidivism three years after the initial assessment was examined. Results indicated that interpersonal traits were positively associated with better facial identification of fearful faces, whereas affective traits were associated with worse facial identification of sad and happy faces as well as angry voices. Impulsive-irresponsible traits were associated with reduced emotional intelligence. Differential predictive utility of the three psychopathic traits dimensions was also evidenced. Findings highlight the need to consider the broad concept of psychopathy, but also its underlying dimensions.

Investigating error-related processing in incarcerated adolescents with self-report psychopathy measures

Disparate results have been found in previous reports when incorporating both interview-based and self-report measures of psychopathic traits within the same sample, suggesting such assessments should not be used interchangeably. We previously found Total and Facet 4 scores from Hare’s Psychopathy Checklist: Youth Version (PCL:YV) were negatively related to amplitude of the error-related positivity (Pe) event-related potential (ERP) component. Here, we investigated using the same previously published sample whether scores on four different self-report measures of adolescent psychopathic traits (the Antisocial Process Screening Device [APSD], Child Psychopathy Scale [CPS], Inventory of Callous-Unemotional Traits [ICU], and Youth Psychopathic Traits Inventory [YPI]) were similarly associated with reduced Pe amplitude. Unlike our previous results, adolescent self-report psychopathy scores were not associated with reduced Pe amplitude in multiple regression analyses. Results obtained in the current report support previous research observing incongruent findings when incorporating different assessment types within the same sample.

Functional connectivity in incarcerated male adolescents with psychopathic traits

The present study examined the association between psychopathic traits and functional connectivity in 177 incarcerated male adolescents. We hypothesized that psychopathic symptoms would be associated with functional connectivity within networks encompassing limbic and paralimbic regions, such as the default mode (DMN), salience networks (SN), and executive control network (ECN). The present sample was drawn from the Southwest Advanced Neuroimaging Cohort, Youth sample, and from research at a youth detention facility in Wisconsin. All participants were scanned at maximum-security facilities. Psychopathic traits were assessed using Hare's Psychopathy Checklist-Youth Version. Resting-state networks were computed using group Independent Component Analysis. Associations between psychopathic traits and resting-state connectivity were assessed using Mancova analyses. PCL-YV Total score and Factor 1 score (interpersonal and affective traits) were associated with the power spectra of the DMN. Factor 1 score was associated with SN and ECN spatial maps. Factor 2 score (lifestyle and antisocial traits) was associated with spatial map of the ECN. Only the Factor 1 association with DMN power spectrum survived correction for multiple testing. Comparable to adult psychopathy, adolescent psychopathic traits were associated with networks implicated in self-referential thought, moral behavior, cognition, and saliency detection: functions previously reported to be disrupted in adult psychopaths.

Triarchic dimensions of psychopathy in young adulthood: Associations with clinical and physiological measures after accounting for adolescent psychopathic traits.

This study examined associations of psychopathy facets of boldness, meanness, and disinhibition with clinically relevant variables and physiological reactivity to affective stimuli. These associations were examined after accounting for developmental associations with adolescent psychopathic traits, namely callous-unemotional traits, narcissism, and impulsivity. Psychopathic traits were assessed during adolescence using the Antisocial Process Screening Device and the Inventory of Callous Unemotional traits and during young adulthood via the Triarchic Psychopathy Measure. Clinical variables (N = 99, Mage = 15.91, 53% female), as well as affective and physiological responses (heart rate, skin conductance, startle modulation) to violent and erotic videos (N = 88, Mage = 19.92, 50% female) were also assessed during adulthood. After accounting for adolescent psychopathic traits, boldness was associated with high cognitive reappraisal and low anxiety, fear, and hostility, and meanness was related to callous-unemotional traits, hostility, less sympathy to victims, and less use of cognitive reappraisal. Disinhibition, by contrast, was associated with impulsivity, increased anxiety, and hostile and aggressive tendencies, as well as conduct disorder, antisocial personality disorder symptoms, and cognitive suppression. In addition, evidence was found for different physiological measures operating as biological indicators of these distinctive dimensions, with reduced resting heart rate and cardiac reactivity to violent stimuli indicative of boldness, above and beyond adolescent psychopathic traits, and low startle potentiation for violent stimuli indicative of callous-unemotional traits and meanness. These findings provide evidence for the value of a multidomain approach for clarifying neurobiological mechanisms of psychopathic tendencies that can inform prevention and treatment efforts. (PsycINFO Database Record

Understanding adolescent psychopathic traits from early risk and protective factors: Relations among inhibitory control, maternal sensitivity, and attachment representation

Psychopathic traits reflect deficits in behavioral, affective, and interpersonal functioning (Cooke & Michie, 2001). Children with poor inhibitory control may display these traits. Maternal sensitivity and attachment have been implicated in psychopathic traits, but whether they may reduce the likelihood of psychopathic trait expression in adolescence for uninhibited children is largely unknown. The current study attempted to shed light on this issue. Data came from 957 adolescents, followed from 54 months through 15 years. Findings demonstrated that maternal sensitivity was associated with a reduced likelihood of psychopathic traits for males with low inhibitory control. For females, secure attachment mediated the interaction of sensitivity and inhibitory control to psychopathic traits. The current study offers insight into the temperamental traits, parenting, and relational processes involved in psychopathic trait expression during adolescence.

Psychopathic traits in adolescents are associated with higher structural connectivity

Altered structural connectivity has been reported in antisocial juveniles, but findings have been inconsistent. Given the phenotypical heterogeneity among individuals showing antisocial behavior, specification of the association between structural connectivity and the dimensions of psychopathic traits (i.e., callous-unemotional, grandiose-manipulative, and impulsive–irresponsible traits) may aid in more reliably elucidating the neural mechanisms underlying antisocial behavior during adolescence. In this study, a sample of 145 adolescents (mean age 17.6, SD 1.6) from a childhood arrestee cohort participated in a neuroimaging protocol including diffusion tensor imaging (DTI). Fractional anisotropy (FA), radial diffusivity (RD) and axial diffusivity (AD), as obtained by tract-based spatial statistics, were associated with juveniles' scores on the Youth Psychopathic Traits Inventory. Grandiose-manipulative traits were positively associated with FA and negatively with RD in a wide range of white matter tracts, suggesting abnormal myelination related to these traits. Callous-unemotional traits were positively associated with FA and AD in specific white matter tracts, including the corpus callosum and corticospinal tract. The differential associations between dimensions of psychopathic traits and measures of structural connectivity support the notion that multiple distinct neural mechanisms underlie antisocial and psychopathic development.

Self-reported psychopathic traits among non-referred Finnish adolescents: psychometric properties of the Youth Psychopathic traits Inventory and the Antisocial Process Screening Device.

BackgroundIn general psychiatric services, cost-benefit screening instruments for psychopathic traits in adolescents are needed. The aim of the present study was to study the psychometric properties of the Finnish versions of the Youth Psychopathic traits Inventory (YPI) and the Antisocial Process Screening Device (APSD-SR) in community youth. As gender-specific differences exist in psychopathic traits, we analyzed the data separately in girls and boys.MethodsThe YPI and the APSD-SR were administered to 372 9th graders (174 boys and 198 girls) with a mean age of 15.06 years (SD 0.28). Cronbach’s alphas were used to study internal consistency. The factor structures of the self-assessments were studied using both Confirmatory Factor Analysis (CFA) and Principal Component Analysis (PCA).ResultsIn both self-assessments, boys scored significantly higher in the total scores, Interpersonal and Affective dimension scores as well as in most sub-dimensions. In the YPI, the alpha values for total and dimensional scores ranged from 0.55 to 0.91 in boys and from 0.74 to 0.89 in girls and, in the APSD-SR, respectively, from 0.38 to 0.78 and from 0.29 to 0.78. In CFA, the three-factor model produced poor fit for both self-assessments. For the ten sub-dimensions of the YPI, the PCA suggested two factors. Extending the model into three components showed sub-dimension loadings according to the original dimensions. For the APSD-SR, the PCA revealed a five-factor structure in the male sample and a six-factor one in the female group. When limiting the model to a three factor- model, we obtained a structure, which resembled the original dimensions.ConclusionsBoth the YPI and the APSD-SR are promising tools of screening for psychopathic features in Finnish community youth. The YPI turned out to be slightly better than the APSD- SR in both reliability and factor structure. However, the original three-factor models did not find support. Both self-assessments were somewhat weak for tapping the callous-unemotional traits of the psychopathic character, but, again, the YPI worked better than the ASPD-SR. Both self-assessments revealed significant gender differences in psychopathic character traits.Electronic supplementary materialThe online version of this article (doi:10.1186/s13034-015-0047-6) contains supplementary material, which is available to authorized users.

Frontal and striatal alterations associated with psychopathic traits in adolescents

Neuroimaging research has demonstrated a range of structural deficits in adults with psychopathy, but little is known about structural correlates of psychopathic tendencies in adolescents. Here we examined structural magnetic resonance imaging (sMRI) data obtained from 14-year-old adolescents (n=108) using tensor-based morphometry (TBM) to isolate global and localized differences in brain tissue volumes associated with psychopathic traits in this otherwise healthy developmental population. We found that greater levels of psychopathic traits were correlated with increased brain tissue volumes in the left putamen, left ansa peduncularis, right superiomedial prefrontal cortex, left inferior frontal cortex, right orbitofrontal cortex, and right medial temporal regions and reduced brain tissues volumes in the right middle frontal cortex, left superior parietal lobule, and left inferior parietal lobule. Post hoc analyses of parcellated regional volumes also showed putamen enlargements to correlate with increased psychopathic traits. Consistent with earlier studies, findings suggest poor decision-making and emotional dysregulation associated with psychopathy may be due, in part, to structural anomalies in frontal and temporal regions whereas striatal structural variations may contribute to sensation-seeking and reward-driven behavior in psychopathic individuals. Future studies will help clarify how disturbances in brain maturational processes might lead to the developmental trajectory from psychopathic tendencies in adolescents to adult psychopathy.