Genetic influences on the overlap between low IQ and antisocial behavior in young children.

Abstract

The well-documented relation between the phenotypes of low IQ and childhood antisocial behavior could be explained by either common genetic influences or environmental influences. These competing explanations were examined through use of the Environmental Risk Longitudinal Twin Study 1994-1995 cohort (Moffitt & the E-Risk Study Team, 2002) of 1,116 twin pairs and their families. Children's IQ was assessed via individual testing at age 5 years. Mothers and teachers reported on children's antisocial behavior at ages 5 and 7 years. Low IQ was related to antisocial behavior at age 5 years and predicted relatively higher antisocial behavior scores at age 7 years when antisocial behavior at age 5 years was controlled. This association was significantly stronger among boys than among girls. Genetic influences common to both phenotypes explained 100% of the low IQ-antisocial behavior relation in boys. Findings suggest that specific candidate genes and neurobiological processes should be tested in relation to both phenotypes. Keywords IQ; antisocial behavior; young children; behavior geneticsEarly-onset antisocial behavior is a strong risk factor for poor mental health, criminality, unemployment, and a host of other adjustment problems in adult life (Moffitt, Caspi, Harrington, & Milne, 2002;Robins, 1966). Understanding the etiology of antisocial behavior in young children is necessary for informing prevention efforts and, therefore, remains an important public health goal. Low IQ is a consistent risk factor for emergence and continuity of antisocial behavior across the life course in both prospective and cross-sectional studies, even when other relevant risk factors are statistically controlled (Hinshaw, 1992;Moffitt & Lynam, 1994;Nigg & Huang-Pollock, 2003;Simonoff et al., 2004). The effect size of the association between low IQ and antisocial behavior ranges from small to medium, with correlations ranging from .20 to .30 across studies, and comparisons of antisocial groups and control groups show half a standard deviation (approximately 8 points) difference in their IQ scores. These findings have been replicated in cohorts throughout the Western world (Hinshaw, 1992;Nigg & Huang-Pollock, 2003). Although the bulk of studies involve adolescents, the Correspondence concerning this article should be addressed to Karestan C. Koenen, Department of Society, Human Development, and Health, Harvard School of Public Health, 677 Huntington Avenue, Kresge 613, Boston, MA 02115. E-mail: kkoenen@hsph.harvard.edu. NIH Public Access NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript association has been reported for preschool children (Moffitt, Caspi, Harrington, & Milne, 2002;Raine, Yaralian, Reynolds, Venables, & Mednick, 2002). The association between IQ and antisocial behavior is, therefore, robust. It is not an artifact of differential detection, socioeconomic status, race, or children's poor effort on the tests (Lynam, Moffitt, & Stouthamer-Loeber, 1993). This article examines the etiology of the ...

The neurocognitive phenotype in velo‐cardio‐facial syndrome: A developmental perspective

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The Relationship of Impulsivity-Inattention and Verbal Ability to Overt and Covert Antisocial Behaviors in Children

“…Some research found that children with conduct disorders scored about eight IQ points lower than their non-disordered counterparts on intelligence tests, scoring particularly lower on the verbal scale (Lynam et al 1993;Prentice and Kelly 1963). Low IQ scores obtained at age 5 also have been related to antisocial behavior scores at age 7 (Koenen et al 2006). The relationship between intellectual deficits and the developmental progression of antisocial behaviors in childhood, adolescence, and adulthood have been well supported by research.…”

Emotional Memory and Emotional Intelligence of Individuals Diagnosed with Anti-Social Personality Disorder: Experimental Pretest-Posttest Design

“…Some other studies discussed ASPD from neuropsychological point of view, they concluded that ASPD individuals tend to suffer from cognitive and behavioral problems due to tampered function in DLPFC and VMPFC area of the brain (Dolan & Park, 2002). In another study conducted by Karestan and Koenen (2008), they studied Genetic Influences on the Overlap between Low IQ and Antisocial Behavior in Young Children; they concluded that Low IQ was associated with antisocial behavior at age 5 years and anticipated comparatively higher antisocial behavior scores at age 7 years when antisocial behavior at age 5 years was controlled. This link was dramatically boosted among boys than among girls.…”

“…Genetic influences mutual to both phenotypes explained 100% of the low IQantisocial behavior relation in boys. Findings suggest that specific candidate genes and neurobiological processes should be tested in relation to both phenotypes (Karestan, Koenen, Terrie, Fruhling, & Alan, 2008). As we can see various clinicians and scientists have assessed various aspects of ASPD individuals function, but current study stands out, because it meticulously assess EM and EI subtypes of these individuals.…”