Etiology of different developmental trajectories of callous-unemotional traits.
ABSTRACT To investigate the longitudinal development of callous-unemotional traits (CU) in middle childhood using developmental trajectory analyses in a large twin dataset and examine the degree to which genetic and environmental influences contributed to the CU trajectory-group membership in children.
The study included 9,462 youths from the Twins Early Development Study, a population-based sample of twins from the United Kingdom. Developmental trajectories were described using teachers' ratings of CU at 7, 9, and 12 years old.
We identified four trajectories of CU through general growth mixture modeling: stable high, increasing, decreasing, and stable low. In most cases, the trajectory-group membership was largely driven by genetic and to a lesser extent by nonshared environmental influences for boys and girls. The most notable exception was a strong contribution of shared environment for the girls in the stable-high trajectory group.
Our findings suggest distinct developmental trajectories of CU from childhood to early adolescence, which are in most cases influenced by genetic factors and, to a lesser degree, by nonshared environmental factors. Highest heritability was observed for boys on a stable-high CU trajectory. Interestingly, the trajectory-group membership for girls on a stable-high CU trajectory appeared to be almost entirely driven by shared environmental influences. These differences in the etiology of stable-high CU in boys and girls have potential implications for clinical practice and studies attempting to identify genetic and environmental risk factors for high CU.
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ABSTRACT: Few studies have examined the etiology of psychopathic traits in youth, and even fewer have tested whether the genetic and environmental influences underlying these traits differ for boys and girls. We tested for sex differences in the etiology of 3 trait dimensions-impulsivity, narcissism, and callous-unemotionality (CU)-previously found to underlie youth psychopathy in our sample. Using biometric modeling we tested whether constraining the genetic and environmental influences for each dimension across sex reduced model fit. We also tested for qualitative sex differences in the influences underlying these dimensions by allowing the genetic and environmental correlations between opposite sex dizygotic twins to be less than their respective values in same-sex dizygotic twins. Although the magnitudes of the genetic and environmental influences underlying the CU and narcissistic trait dimensions did not differ for boys and girls, nonshared environmental influences contributed significantly greater variance to impulsive traits in boys. No qualitative sex differences were found in the influences underlying any of the 3 trait dimensions, suggesting that the same genes and environments contribute to these psychopathic traits in males and females. (PsycINFO Database Record (c) 2014 APA, all rights reserved).Journal of Abnormal Psychology 05/2014; 123(2):406-411. DOI:10.1037/a0036457 · 4.86 Impact Factor
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ABSTRACT: Background. Previous research has supported gender-specific aetiological factors in oppositional defiant disorder (ODD) and conduct disorder (CD). The aims of this study were to identify gender-specific associations between the behavioural problems–ODD/CD-like problems–and the neurodevelopmental disorders–attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD)–and to investigate underlying genetic effects. Methods. 17,220 twins aged 9 or 12 were screened using the Autism–Tics, AD/HD and other Comorbidities inventory. The main covariates of ODD- and CD-like problems were investigated, and the relative importance of unique versus shared hereditary and environmental effects was estimated using twin model fitting. Results. Social interaction problems (one of the ASD subdomains) was the strongest neurodevelopmental covariate of the behavioural problems in both genders, while ADHD-related hyperactivity/impulsiveness in boys and inattention in girls stood out as important covariates of CD-like problems. Genetic effects accounted for 50%–62% of the variance in behavioural problems, except in CD-like problems in girls (26%). Genetic and environmental effects linked to ADHD and ASD also influenced ODD-like problems in both genders and, to a lesser extent, CD-like problems in boys, but not in girls. Conclusions. The gender-specific patterns should be considered in the assessment and treatment, especially of CD.04/2014; 2:e359. DOI:10.7717/peerj.359
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ABSTRACT: Until now, no study has examined the genetic and environmental influences on psychopathic personality across different raters and method of assessment. Participants were part of a community sample of male and female twins born between 1990 and 1995. The Child Psychopathy Scale and the Antisocial Process Screening Device were administered to the twins and their parents when the twins were 14-15 years old. The Psychopathy Checklist: Youth Version (PCL:YV) was administered and scored by trained testers. Results showed that a 1-factor common pathway model was the best fit for the data. Genetic influences explained 69% of the variance in the latent psychopathic personality factor, while nonshared environmental influences explained 31%. Measurement-specific genetic effects accounted for between 9% and 35% of the total variance in each of the measures, except for PCL:YV, where all genetic influences were in common with the other measures. Measure-specific nonshared environmental influences were found for all measures, explaining between 17% and 56% of the variance. These findings provide further evidence of the heritability in psychopathic personality among adolescents, although these effects vary across the ways in which these traits are measured, in terms of both informant and instrument used. (PsycINFO Database Record (c) 2014 APA, all rights reserved).Psychological Assessment 05/2014; 26(3). DOI:10.1037/a0036711 · 2.99 Impact Factor