Genetic and environmental influences on antisocial behavior: a meta-analysis of twin and adoption studies

A meta-analysis of 51 twin and adoption studies was conducted to estimate the magnitude of genetic and environmental influences on antisocial behavior. The best fitting model included moderate proportions of variance due to additive genetic influences (.32), nonadditive genetic influences (.09), shared environmental influences (.16), and nonshared environmental influences (.43). The magnitude of familial influences (i.e., both genetic and shared environmental influences) was lower in parent-offspring adoption studies than in both twin studies and sibling adoption studies. Operationalization, assessment method, zygosity determination method, and age were significant moderators of the magnitude of genetic and environmental influences on antisocial behavior, but there were no significant differences in the magnitude of genetic and environmental influences for males and females.     

Sex differences in the genetic and environmental influences on childhood conduct disorder and adult antisocial behavior

Sex differences in the genetic and environmental influences on childhood conduct disorder and adult antisocial behavior were examined in a large community sample of 6,383 adult male, female, and opposite-sex twins. Retrospective reports of childhood conduct disorder (prior to 18 years of age) were obtained when participants were approximately 30 years old, and lifetime reports of adult antisocial behavior (antisocial behavior after 17 years of age) were obtained 8 years later. Results revealed that either the genetic or the shared environmental factors influencing childhood conduct disorder differed for males and females (i.e., a qualitative sex difference), but by adulthood, these sex-specific influences on antisocial behavior were no longer apparent. Further, genetic and environmental influences accounted for proportionally the same amount of variance in antisocial behavior for males and females in childhood and adulthood (i.e., there were no quantitative sex differences). Additionally, the stability of antisocial behavior from childhood to adulthood was slightly greater for males than females. Though familial factors accounted for more of the stability of antisocial behavior for males than females, genetic factors accounted for the majority of the covariation between childhood conduct disorder and adult antisocial behavior for both sexes. The genetic influences on adult antisocial behavior overlapped completely with the genetic influences on childhood conduct disorder for both males and females. Implications for future twin and molecular genetic studies are discussed.     

Socioeconomic status modifies heritability of IQ in young children

Scores on the Wechsler Intelligence Scale for Children were analyzed in a sample of 7-year-old twins from the National Collaborative Perinatal Project. A substantial proportion of the twins were raised in families living near or below the poverty level. Biometric analyses were conducted using models allowing for components attributable to the additive effects of genotype, shared environment, and nonshared environment to interact with socioeconomic status (SES) measured as a continuous variable. Results demonstrate that the proportions of IQ variance attributable to genes and environment vary nonlinearly with SES. The models suggest that in impoverished families, 60% of the variance in IQ is accounted for by the shared environment, and the contribution of genes is close to zero; in affluent families, the result is almost exactly the reverse.     

The relation between anger and antisocial beliefs in young offenders

The tendency for youth to report antisocial beliefs has been identified as a major risk factor in delinquency. Advances in emotion research suggest the importance of examining the emotional concomitants of cognitive appraisals such as antisocial beliefs. The present study examined the relation between anger and antisocial beliefs in a sample of young offenders and investigated whether scores on either variable differentiated aggressive from non-aggressive offenders. Twenty-two aggressive and 20 nonaggressive young offenders were compared on two questionnaires measuring anger and antisocial beliefs, respectively. The findings revealed a significant correlation between the two measures. In addition, it was found that the aggressive offenders, compared to their non-aggressive counterparts, scored significantly higher on anger and antisocial beliefs. These findings extended previous research on the characteristics that differentiate aggressive and non-aggressive offenders. Results also support the rationale for incorporating both cognitive and affective components in intervention programs designed for aggressive young offenders.     

The relations between type A behavior, clinically relevant behavior, academic achievement, and IQ in children

The relation of Type A behavior to IQ, academic achievement, and several clinically relevant dimensions of behavior in children was assessed in 873 fourth, fifth, and sixth graders by means of the Matthews Youth Test for Health (MYTH), the Cognitive Abilities Test (CAT), the Iowa Tests of Basic Skills (ITED), and the teachers' form of the Missouri Children's Behavior Checklist (MCBC-T). The MYTH and its competitiveness and impatience-aggression subscales were found to be differentially related to academic achievement and to account for a small but significant portion of the variance in achievement not accounted for by IQ. The subscales of the MYTH were found to be highly correlated with several clinically familiar dimensions of children's behavior. The significance of these findings for the construct validity of the MYTH is discussed.     

A gender-linked exploratory factor analysis of antisocial behavior in young adolescents

One hundred sixty-three young adolescents (72 males, 91 females) were administered a 23-item self-report inventory measuring antisocial behaviors. Results were analyzed separately for males and females. Exploratory factor analysis showed antisocial behavior to be multidimensional and to have different factor structures for males and females. The three factors accounting for more than two-thirds of the variance in antisocial behavior are discussed in terms of specialization in drug/alcohol use and violence.     

Genetic and environmental influences on behavior: capturing all the interplay

Basic quantitative genetic models of human behavioral variation have made clear that individual differences in behavior cannot be understood without acknowledging the importance of genetic influences. Yet these basic models estimate average, population-level genetic and environmental influences, obscuring differences that might exist within the population and masking systematic transactions between specific genetic and environmental influences. This article discusses a newer, more sophisticated and powerful quantitative genetic model that articulates these transactions. Results from this model highlight the ways in which the gene- environment interaction and correlation are intertwined. They can be used to integrate findings from quantitative and molecular genetic studies and to understand the roles of genetic influences and social forces in manifested behaviors, even when DNA sequence variation is not relevant.     

The relationship between multisensory integration and IQ in children

It is well accepted that multisensory integration has a facilitative effect on perceptual and motor processes, evolutionarily enhancing the chance of survival of many species, including humans. Yet, there is limited understanding of the relationship between multisensory processes, environmental noise, and children's cognitive abilities. Thus, this study investigated the relationship between multisensory integration, auditory background noise, and the general intellectual abilities of school-age children (N = 88, mean age = 9 years, 7 months) using a simple audiovisual detection paradigm. We provide evidence that children with enhanced multisensory integration in quiet and noisy conditions are likely to score above average on the Full-Scale IQ of the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV). Conversely, approximately 45% of tested children, with relatively low verbal and nonverbal intellectual abilities, showed reduced multisensory integration in either quiet or noise. Interestingly, approximately 20% of children showed improved multisensory integration abilities in the presence of auditory background noise. The findings of the present study suggest that stable and consistent multisensory integration in quiet and noisy environments is associated with the development of optimal general intellectual abilities. Further theoretical implications are discussed.     

Preventing antisocial behavior in the schools

Multiple correlates and determinants of antisocial behavior within the home, community, and school are reviewed. Due to the school's pivotal role in our society, an emphasis is placed on how our schools contribute to antisocial behavior, and what educators can do to prevent anti-social behavior and related attendance problems. A variety of contextual factors and setting events within our schools appear to be major contributors to antisocial behavior, and some of the same factors identified within the schools also have been identified within the home. These setting events, rather than quick restrictive fixes, must be given more attention if we are to provide safe school environments-environments that durably prevent antisocial behavior and related attendance problems.     

Romantic relationships of young people with childhood and adolescent onset antisocial behavior problems

Using prospective longitudinal data from the Christchurch Health and Development Study, this paper examines the extent to which early onset, life course persistent and adolescent limited antisocial behavior problems place young people at risk of violent and unsatisfactory romantic relationships in early adulthood. Results revealed the presence of clear linear associations between the developmental timing of antisocial behavior and later partnership risks, with these risks including partner violence perpetration and victimization, interpartner conflict, and increased ambivalence about the relationship. Young people with childhood onset antisocial behavior problems reported higher rates of partnership difficulties than young people with adolescent limited antisocial behavior problems, while those with adolescent limited antisocial behavior reported higher levels of partnership difficulties than young people without a history of antisocial behavior problems. These associations persisted even after extensive control for a range of social, family, and individual factors that were correlated with the timing of antisocial behavior. Results highlight the importance of distinguishing between early and late onset antisocial behavior, and provide further support for existing life course models of the development of antisocial behavior problems in children and adolescents.     

Genetic and environmental bases of childhood antisocial behavior: a multi-informant twin study

Genetic and environmental influences on childhood antisocial and aggressive behavior (ASB) during childhood were examined in 9- to 10-year-old twins, using a multi-informant approach. The sample (605 families of twins or triplets) was socioeconomically and ethnically diverse, representative of the culturally diverse urban population in Southern California. Measures of ASB included symptom counts for conduct disorder, ratings of aggression, delinquency, and psychopathic traits obtained through child self-reports, teacher, and caregiver ratings. Multivariate analysis revealed a common ASB factor across informants that was strongly heritable (heritability was .96), highlighting the importance of a broad, general measure obtained from multiple sources as a plausible construct for future investigations of specific genetic mechanisms in ASB. The best fitting multivariate model required informant-specific genetic, environmental, and rater effects for variation in observed ASB measures. The results suggest that parents, children, and teachers have only a partly "shared view" and that the additional factors that influence the "rater-specific" view of the child's antisocial behavior vary for different informants. This is the first study to demonstrate strong heritable effects on ASB in ethnically and economically diverse samples.     

Psychophysical design influences frequency discrimination performance in young children

We investigated how different psychophysical procedures affect frequency discrimination performance in children. Four studies used a design in which listeners heard two tone pairs and had to identify whether the first or second pair contained a higher frequency target tone. Thresholds for 6- and 7-year-olds were higher than those for 8- and 9-year-olds and adults. Two manipulations led to lower (better) thresholds in young children: (a) moving the standard comparison tone before the target tone and (b) using three target comparison tone pairs. It is suggested that young children benefit from designs that help cue them to when they need to attend to a target tone. The two-interval, forced-choice procedure that is widely used in studies of developmental disorders led to variable performance even in adults and did not give a realistic picture of the perceptual capabilities of children under 8 years of age.     

Biosocial studies of antisocial and violent behavior in children and adults: a review

Despite increasing knowledge of social and biological risk factors for antisocial and violent behavior, we know surprisingly little about how these two sets of risk factors interact. This paper documents 39 empirical examples of biosocial interaction effects for antisocial behavior from the areas of genetics, psychophysiology, obstetrics, brain imaging, neuropsychology, neurology, hormones, neurotransmitters, and environmental toxins. Two main themes emerge. First, when biological and social factors are grouping variables and when antisocial behavior is the outcome, then the presence of both risk factors exponentially increases the rates of antisocial and violent behavior. Second, when social and antisocial variables are grouping variables and biological functioning is the outcome, then the social variable invariably moderates the antisocial–biology relationship such that these relationships are strongest in those from benign home backgrounds. It is argued that further biosocial research is critical for establishing a new generation of more successful intervention and prevention research.     

Cognitive and developmental influences in visual-motor integration skills in young children

Measures of visual-motor integration skills continue to be widely used in psychological assessments with children. However, the construct validity of many visual-motor integration measures remains unclear. In this study, we investigated the relative contributions of maturation and cognitive skills to the development of visual-motor integration skills in young children (N = 856). We used a block regression analysis to determine the contribution of maturation, as indicated by age, followed by broad cognitive factors (Study 1) and subsequently by individual subtests in verbal and nonverbal domains subsumed under each factor (Study 2) in explaining score variance of the Bender Visual-Motor Gestalt Test (2nd ed.; BG-II; Brannigan & Decker, 2003) Copy and Recall scores in children between the ages of 4 and 7 years. Results confirm that maturation accounted for a large proportion of variance in both BG-II Copy and Recall performance, above which Stanford-Binet Intelligence Scale (5th ed.; SB-5; Roid, 2003) Quantitative Reasoning and Fluid Reasoning factors significantly contributed to visual-motor integration performance for the Copy phase, and SB-5 Quantitative Reasoning and Visual-Spatial factors accounted for a significant amount of variance for the Recall phase. Additionally, nonverbal domains were more related to visual-motor performance than verbal domains. Results from this study are interpreted to suggest nonverbal reasoning and visual-spatial attention are important contributing factors to visual-motor integration, as measured by the BG-II. Developmental implications of visual-motor integration skills, nonverbal problem solving, and mathematical competence are discussed.     

Impulsiveness and antisocial behaviour in children

An Impulsiveness inventory was completed by 118 boys and 309 girls from London comprehensive schools. Of these, 101 boys and 306 girls also completed the Eysenck Junior Personality Questionnaire and an Antisocial Behaviour Scale. Intercorrelations of the scores suggest that there is a strong link between antisocial behaviour in children and impulsiveness, as well as psychoticism or toughmindedness, and a weaker link with venturesomeness, extraversion and lack of empathy. Neuroticism was only slightly implicated for girls and hardly at all for boys.     

Aggressive and nonaggressive antisocial behavior in adolescence

This study examined whether a distinction between aggressive and nonaggressive antisocial behavior can be empirically verified in a large (254 girls and 254 boys) nonclinical (community) sample of Dutch adolescents between 12 and 18 years old. The results of confirmatory factor analysis for both boys and girls shows that aggressive and nonaggressive antisocial behaviors do not represent a single underlying dimension, but two separate constructs with moderate independence among them. These findings suggest that the conceptualization of adolescent antisocial behavior as a one-dimensional phenomenon is of questionable utility and supports growing evidence that aggressive antisocial behavior is distinct from other forms of antisocial behavior.     

Genetic and experiential influences on behavior: Twins reunited at seventy-eight years

Twins living in different countries offer opportunities to explore associations between observed differences and experiential effects. This report compared the life histories, cognitive abilities, personality traits, psychomotor skills, medical characteristics, job satisfaction, social support and social relations of dizygotic (DZ) female twins reunited at 78, the world’s longest separated set. The twins’ advanced age also enabled a study of how co-twin differences in aging may be associated with current behavioral and social differences. Consistent with previous studies, these dizygotic reared apart (DZA) twins showed discordance across some, but not all, traits. Their different rearing situations and life histories may explain current differences in their responses to meeting their twin. This case highlights the importance of both genetic and rearing factors on behavior, but does not allow firm conclusions regarding the extent to which these sources explain individual developmental differences. However, such data contribute to the growing number of cross-culturally separated twins, generating novel hypotheses that may be assessed using larger samples.