| 1. |
- Isen, Joshua, et al.
(författare)
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Developmental Trajectories of Delinquent and Aggressive Behavior : Evidence for Differential Heritability
- 2022
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Ingår i: Child Psychiatry and Human Development. - : Springer. - 0009-398X .- 1573-3327. ; 53:2, s. 199-211
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Tidskriftsartikel (refereegranskat)abstract
- The developmental course of antisocial behavior is often described in terms of qualitatively distinct trajectories. However, the genetic etiology of various trajectories is not well understood. We examined heterogeneity in the development of delinquent and aggressive behavior in 1532 twin youth using four waves of data collection, spanning ages 9-10 to 16-18. A latent class growth analysis was used to uncover relevant subgroups. For delinquent behavior, three latent classes emerged: Non-Delinquent, Low-Level Delinquent, and Persistent Delinquent. Liability for persistent delinquency had a substantial genetic origin (heritability = 67%), whereas genetic influences were negligible for lower-risk subgroups. Three classes of aggressive behavior were identified: Non-Aggressive, Moderate, and High. Moderate heritability spanned the entire continuum of risk for aggressive behavior. Thus, there are differences between aggressive behavior and non-aggressive delinquency with respect to heterogeneity of etiology. We conclude that persistent delinquency represents an etiologically distinct class of rule-breaking with strong genetic roots.
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| 2. |
- Isen, Joshua, et al.
(författare)
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Heritability of skin conductance reactivity in children
- 2008
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Ingår i: Behavior Genetics. - : Springer Science and Business Media LLC. - 0001-8244 .- 1573-3297. ; 38:6, s. 632-632
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- This study assessed the genetic covariance between various measures of phasic skin conductance activity, including response amplitude and frequency of responding. A few studies have investigated the etiology of skin conductance reactivity (e.g., Lykken et al. Psychophysiology 25:4–15, 1988), but none have been conducted with children. Given that deficits in skin conductance orienting are associated with psychosis-proneness and conduct problems, it is important to understand the genetic and environmental contributions to skin conductance reactivity in children. Subjects for this study were 800 male and female twins, aged 9–10, who passively listened to stimuli during an orienting task. The stimuli consisted of tones of moderate intensity (75 dB), as well as different types of socially meaningful sounds (e.g. baby cries and speech-like stimuli). Skin conductance response magnitude, averaged across all stimuli, was substantially heritable. Genetic modelfitting was used to determine if the variation in reactivity across the different types of stimuli can be explained by a single latent factor. Furthermore, there was a moderate phenotypic correlation between a continuous measure of reactivity (i.e. response amplitude) and a more categorical measure of skin conductance (i.e. frequency of responding). This association was not genetically mediated, suggesting a theoretical distinction between hyporeactivity and nonresponding.
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| 3. |
- Jackson, Nicholas J., et al.
(författare)
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Impact of adolescent marijuana use on intelligence : Results from two longitudinal twin studies
- 2016
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 113:5, s. E500-E508
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Tidskriftsartikel (refereegranskat)abstract
- Marijuana is one of the most commonly used drugs in the United States, and use during adolescence-when the brain is still developing-has been proposed as a cause of poorer neurocognitive outcome. Nonetheless, research on this topic is scarce and often shows conflicting results, with some studies showing detrimental effects of marijuana use on cognitive functioning and others showing no significant long-term effects. The purpose of the present study was to examine the associations of marijuana use with changes in intellectual performance in two longitudinal studies of adolescent twins (n = 789 and n = 2,277). We used a quasiexperimental approach to adjust for participants' family background characteristics and genetic propensities, helping us to assess the causal nature of any potential associations. Standardized measures of intelligence were administered at ages 9-12 y, before marijuana involvement, and again at ages 17-20 y. Marijuana use was self-reported at the time of each cognitive assessment as well as during the intervening period. Marijuana users had lower test scores relative to nonusers and showed a significant decline in crystallized intelligence between preadolescence and late adolescence. However, there was no evidence of a dose-response relationship between frequency of use and intelligence quotient (IQ) change. Furthermore, marijuana-using twins failed to show significantly greater IQ decline relative to their abstinent siblings. Evidence from these two samples suggests that observed declines in measured IQ may not be a direct result of marijuana exposure but rather attributable to familial factors that underlie both marijuana initiation and low intellectual attainment.
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| 4. |
- Tuvblad, Catherine, 1968-, et al.
(författare)
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The genetic and environmental etiology of sympathetic and parasympathetic activity in children
- 2010
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Ingår i: Behavior Genetics. - : Springer Science and Business Media LLC. - 0001-8244 .- 1573-3297. ; 40:4, s. 452-466
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Tidskriftsartikel (refereegranskat)abstract
- The present study examines the genetic and environmental etiology of the associations among respiratory sinus arrhythmia (RSA), heart rate (HR), skin conductance level (SCL), and non-specific skin conductance responses (NS-SCR)-measures that purportedly index the parasympathetic and sympathetic branches of the autonomic nervous system. The sample was drawn from a cohort of 1,219 preadolescent twins (aged 9-10). Multivariate analyses of the data were conducted using structural equation modeling. Almost all genetic and environmental influences on the measures acted through two latent factors. The first latent factor was largely responsible for the variance in heart rate, SCL and NS-SCR, reflecting sympathetic activity, and its proportions of variance due to genetic and shared environmental influences were 27 and 28% in males, and 31 and 41% in females, respectively. The second latent factor accounted for the variance in RSA and heart rate, reflecting parasympathetic activity; genetic and shared environmental factors explained 27 and 23% of the variance in males, respectively, and 35 and 18% of the variance in females. Measurement-specific genetic effects accounted for 14-27% of the total variance in RSA and SCL, and measurement- specific shared environmental effects accounted for 10-12% in SCL. In general, the validity of separate sympathetic and parasympathetic constructs was supported.
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| 5. |
- Tuvblad, Catherine, 1968-, et al.
(författare)
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The heritability of the skin conductance orienting response : a longitudinal twin study
- 2011
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Ingår i: Biological Psychology. - : Elsevier BV. - 0301-0511 .- 1873-6246. ; 89:1, s. 47-53
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Tidskriftsartikel (refereegranskat)abstract
- The orienting response is a widely used experimental paradigm that reflects the association between electrodermal activity and psychological processes. The present study examined the genetic and environmental etiology of skin conductance orienting response (SCOR) magnitude in a sample of twins assessed at ages 9-10, 11-13 and 14-16 years. Structural equation modeling at each visit showed that genetic influences explained 56%, 83%, and 48% of the total variance in SCOR at visits 1, 2, and 3, respectively, with the remaining variance explained by non-shared environmental factors. SCOR was moderately stable across ages, with phenotypic correlations between time points ranging from .35 to .45. A common genetic factor explained 36%, 45% and 49% of the variance in SCOR magnitude across development. Additional age-specific genetic effects were found at ages 9-10 and 11-13 years, explaining 18% and 35% of the variance, respectively. The genetic correlations among the three time points were high, ranging from .55 to .73, indicating a substantial continuity in genetic influences from ages 9 to 16. These findings suggest that genetic factors are important influences in SCOR magnitude during late childhood and adolescence.
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| 6. |
- Wang, Pan, et al.
(författare)
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Genetic covariance between psychopathic traits and anticipatory skin conductance responses to threat : evidence for a potential endophenotype
- 2015
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Ingår i: Development and psychopathology (Print). - : Cambridge University Press. - 0954-5794 .- 1469-2198. ; 27:4, s. 1313-1322
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Tidskriftsartikel (refereegranskat)abstract
- The genetic architecture of the association between psychopathic traits and reduced skin conductance responses (SCRs) is poorly understood. By using 752 twins aged 9–10 years, this study investigated the heritability of two SCR measures (anticipatory SCRs to impending aversive stimuli and unconditioned SCRs to the aversive stimuli themselves) in a countdown task. The study also investigated the genetic and environmental sources of the covariance between these SCR measures and two psychopathic personality traits: impulsive/disinhibited (reflecting impulsive–antisocial tendencies) and manipulative/deceitful (reflecting the affective–interpersonal features). For anticipatory SCRs, 27%, 14%, and 59% of the variation was due to genetic, shared environmental, and nonshared environmental effects, respectively, while the percentages for unconditioned SCRs were 44%, 2%, and 54%. The manipulative/deceitful (not impulsive/disinhibited) traits were negatively associated with both anticipatory SCRs (r¼–.14,p,.05) and unconditioned SCRs (r¼–.17,p,.05) in males only, with the former association significantly accounted for by genetic influences (rg¼–.72). Reduced anticipatory SCRs representa candidate endophenotype for the affective–interpersonal facets of psychopathic traits in males.
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