Frank Vitaro

McGill University, Montréal, Quebec, Canada

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Publications (344)998.58 Total impact

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    ABSTRACT: Little is known about why people differ in their levels of academic motivation. This study explored the etiology of individual differences in enjoyment and self-perceived ability for several school subjects in nearly 13,000 twins aged 9–16 from 6 countries. The results showed a striking consistency across ages, school subjects, and cultures. Contrary to common belief, enjoyment of learning and children’s perceptions of their competence were no less heritable than cognitive ability. Genetic factors explained approximately 40% of the variance and all of the observed twins’ similarity in academic motivation. Shared environmental factors, such as home or classroom, did not contribute to the twin’s similarity in academic motivation. Environmental influences stemmed entirely from individual specific experiences.
    Personality and Individual Differences 07/2015; 80:51-63. DOI:10.1016/j.paid.2015.02.006 · 1.86 Impact Factor
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    ABSTRACT: Background Little is known about how children differ in the onset and evolution of separation anxiety (SA) symptoms during the preschool years, and how SA develops into separation anxiety disorder. In a large, representative population-based sample, we investigated the developmental trajectories of SA symptoms from infancy to school entry, their early associated risk factors, and their associations with teachers' ratings of SA in kindergarten.Methods Longitudinal assessment of SA trajectories and risk factors in a cohort of 1,933 families between the ages of 1.5 and 6 years.ResultsAnalyses revealed a best-fitting, 4-trajectory solution, including a prevailing, unaffected Low-Persistent group (60.2%), and three smaller groups of distinct developmental course: a High-Increasing (6.9%), a High-Decreasing (10.8%), and a Low-Increasing group (22.1%). The High-Increasing group remained high throughout the preschool years and was the only trajectory to predict teacher-assessed SA at age 6 years. Except for the High-Increasing, all trajectories showed substantial reduction in symptoms by age 6 years. The High-Increasing and High-Decreasing groups shared several early risk factors, but the former was uniquely associated with higher maternal depression, maternal smoking during pregnancy, and parental unemployment.Conclusions Most children with high SA profile at age 1.5 years are expected to progressively recover by age 4–5. High SA at age 1.5 that persists over time deserves special attention, and may predict separation anxiety disorder. A host of child perinatal, parental and family-contextual risk factors were associated with the onset and developmental course of SA across the preschool years.
    Journal of Child Psychology and Psychiatry 04/2015; DOI:10.1111/jcpp.12419 · 5.67 Impact Factor
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    ABSTRACT: This study aims to document the prevalence of repeated patterns of dating victimization and to examine, within the frameworks of an ecological model and lifestyle/routine activities theories, associations between such patterns and family, peer, and individual factors. Dating victimization in adolescence (age 15) and early adulthood (age 21) was evaluated in 443 female participants. Multinomial logistic regression analyses revealed that history of family violence, childhood behavior problems, and adolescent high-risk behaviors were associated with an increased risk for girls of being victimized (psychologically and/or physically/sexually) in their dating relationships, either in adolescence or early adulthood, or at both developmental periods. © The Author(s) 2015.
    Violence Against Women 04/2015; 21(4):435-59. DOI:10.1177/1077801215570481 · 1.33 Impact Factor
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    ABSTRACT: Many victimized youngsters are at risk of developing internalizing problems, and this risk seems to be especially pronounced when they are genetically vulnerable for these problems. It is unclear, however, whether protective features of the school environment such as anti-bullying classroom policies and teacher's perceived self-efficacy in handling bullying situations can mitigate these negative outcomes. Using a genetically informed design based on twins, this study examined the potential moderating role of classroom anti-bullying policies and teachers' perceived self-efficacy in handling bullying situations in regard to the additive and interactive effects of peer victimization and genetic vulnerability on anxiety symptoms. To this end, 208 monozygotic and same-sex dizygotic twins (120 girls) rated their level of anxiety and peer victimization in grade 6 (mean age = 12.1 years, SD = 2.8). Teachers rated their self-efficacy in handling bullying situations and the extent of anti-bullying classroom policies. Multilevel regressions revealed triple interactions showing that genetic disposition for anxiety predicted actual anxiety for twins who were highly victimized by their peers, but only when their teachers had low perceived self-efficacy in handling bullying situations or when anti-bullying classroom rules were absent or rarely enforced. In contrast, for victimized youth with teachers who perceive themselves as effective or in classrooms where anti-bullying classroom policies were strongly enforced, genetic disposition for anxiety was not associated with actual anxiety symptoms. Anti-bullying programs should continue to promote teachers' involvement, as well as the enforcement of anti-bullying classroom policies, in order to diminish peer victimization and its related consequences.
    Journal of Abnormal Child Psychology 03/2015; DOI:10.1007/s10802-015-0001-3 · 3.09 Impact Factor
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    ABSTRACT: This study examined (a) whether, in line with a gene-environment correlation (rGE), a genetic disposition for anxiety puts children at risk of having anxious friends or having no reciprocal friends; (b) to what extent these friendship experiences are related to anxiety symptoms, when controlling for sex and genetic disposition for this trait; and (c) the additive and interactive predictive links of the reciprocal best friend's anxiety symptoms and of friendship quality with children's anxiety symptoms. Using a genetically informed design based on 521 monozygotic and ic twins (264 girls; 87% of European descent) assessed in Grade 4 (M age = 10.04 years, SD = .26), anxiety symptoms and perceived friendship quality were measured with self-report questionnaires. Results indicated that, in line with rGE, children with a strong genetic disposition for anxiety were more likely to have anxious friends than nonanxious friends. Moreover, controlling for their genetic risk for anxiety, children with anxious friends showed higher levels of anxiety symptoms than children with nonanxious friends but did not differ from those without reciprocal friends. Additional analyses suggested a possible contagion of anxiety symptoms between reciprocal best friends when perceived negative features of friendship were high. These results underline the importance of teaching strategies such as problem solving that enhance friendship quality to limit the potential social contagion of anxiety symptoms.
    Journal of Clinical Child & Adolescent Psychology 02/2015; DOI:10.1080/15374416.2014.987382 · 1.92 Impact Factor
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    ABSTRACT: The present study examined sibling influence over reactive and proactive aggression in a sample of 452 same-sex twins (113 male dyads, 113 female dyads). Between and within siblings influence processes were examined as a function of relative levels of parental coercion and hostility to test the hypothesis that aggression contagion between twins occurs only among dyads who experience parental coerciveness. Teacher reports of reactive and proactive aggression were collected for each twin in kindergarten (M = 6.04 years; SD = 0.27) and in first grade (M = 7.08 years; SD = 0.27). Families were divided into relatively low, average, and relatively high parental coercion-hostility groups on the basis of maternal reports collected when the children were 5 years old. In families with relatively high levels of parental coercion-hostility, there was evidence of between-sibling influence, such that one twin's reactive aggression at age 6 predicted increases in the other twin's reactive aggression from ages 6 to 7, and one twin's proactive aggression at age 6 predicted increases in the other twin's proactive aggression from ages 6 to 7. There was also evidence of within-sibling influence such that a child's level of reactive aggression at age 6 predicted increases in the same child's proactive aggression at age 7, regardless of parental coercion-hostility. The findings provide new information about the etiology of reactive and proactive aggression and individual differences in their developmental interplay.
    Aggressive Behavior 02/2015; · 2.27 Impact Factor
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    ABSTRACT: This study tested 2 related hypotheses. The first holds that high co-rumination anticipates heightened internalizing problems. The second holds that positive relationships with friends exacerbate the risk for internalizing problems arising from co-rumination. A sample of MZ twins followed from birth (194 girls and 170 boys) completed (a) self-reports of friendship support, friendship negativity, and co-rumination with friends at age 12 and (b) measures of anxiety and depression at ages 12 and 13. Using a monozygotic twins-difference design, within-pair differences in co-rumination predicted increased within-pair differences in anxiety (but not depression), after removing the covariance between co-rumination and perceptions of friendship. In other words, the difference in co-rumination within each monozygotic twin pair predicted an increase in the difference in their anxiety levels, but not the difference in their depression levels. The discussion focuses on nonshared environmental influences, because the monozygotic twin-difference design eliminates the possibility that associations were driven by heritability or by shared environmental factors that underlie friendship experiences and internalizing problems. (PsycINFO Database Record (c) 2015 APA, all rights reserved).
    Developmental Psychology 02/2015; DOI:10.1037/a0038848 · 3.21 Impact Factor
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    ABSTRACT: The present study examined sibling influence over reactive and proactive aggression in a sample of 452 same-sex twins (113 male dyads, 113 female dyads). Between and within siblings influence processes were examined as a function of relative levels of parental coercion and hostility to test the hypothesis that aggression contagion between twins occurs only among dyads who experience parental coerciveness. Teacher reports of reactive and proactive aggression were collected for each twin in kindergarten (M = 6.04 years; SD = 0.27) and in first grade (M = 7.08 years; SD = 0.27). Families were divided into relatively low, average, and relatively high parental coercion-hostility groups on the basis of maternal reports collected when the children were 5 years old. In families with relatively high levels of parental coercion-hostility, there was evidence of between-sibling influence, such that one twin's reactive aggression at age 6 predicted increases in the other twin's reactive aggression from ages 6 to 7, and one twin's proactive aggression at age 6 predicted increases in the other twin's proactive aggression from ages 6 to 7. There was also evidence of within-sibling influence such that a child's level of reactive aggression at age 6 predicted increases in the same child's proactive aggression at age 7, regardless of parental coercion-hostility. The findings provide new information about the etiology of reactive and proactive aggression and individual differences in their developmental interplay. Aggr. Behav. 9999:1-12, 2015. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.
    Aggressive Behavior 02/2015; DOI:10.1002/ab.21582 · 2.27 Impact Factor
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    ABSTRACT: Background The phenotypic and genetic associations between decoding skills and ADHD dimensions have been documented but less is known about the association with reading comprehension. The aim of the study is to document the phenotypic and genetic associations between reading comprehension and ADHD dimensions of inattention and hyperactivity/impulsivity in early schooling and compare them to those with decoding skills.Methods Data were collected in two population-based samples of twins (Quebec Newborn Twin Study – QNTS) and singletons (Quebec Longitudinal Study of Child Development – QLSCD) totaling ≈ 2300 children. Reading was assessed with normed measures in second or third grade. Teachers assessed ADHD dimensions in kindergarten and first grade.ResultsBoth decoding and reading comprehension were correlated with ADHD dimensions in a similar way: associations with inattention remained after controlling for the other ADHD dimension, behavior disorder symptoms and nonverbal abilities, whereas associations with hyperactivity/impulsivity did not. Genetic modeling showed that decoding and comprehension largely shared the same genetic etiology at this age and that their associations with inattention were mostly explained by shared genetic influences.Conclusion Both reading comprehension and decoding are uniquely associated with inattention through a shared genetic etiology.
    Journal of Child Psychology and Psychiatry 02/2015; DOI:10.1111/jcpp.12394 · 5.67 Impact Factor
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    ABSTRACT: In the current prospective study, we investigated (1) whether high and low BMI in early childhood puts a child at risk of victimization by their peers, and (2) whether being victimized increases BMI over the short- and long-term, independent of the effect of BMI on victimization. We also examined whether gender moderated these prospective associations. Participants were 1,344 children who were assessed yearly from ages 3 to 10 years as part of the Québec Longitudinal Study of Child Development (QLSCD). BMI predicted annual increases in victimization for girls aged 6 years and over; for boys aged 7 and 8 years of age, higher BMI reduced victimization over the school year. Further, victimization predicted annual increases in BMI for girls after age 6 years. When these short-term effects were held constant, victimization was also shown to have a three and 5-year influence on annual BMI changes for girls from age 3 years. These short- and long-term cross-lagged effects were evident when the effects of family adversity were controlled. The findings support those from previous prospective research showing a link between higher BMI and victimization, but only for girls. Further, being victimized increased the likelihood that girls would put on weight over time, which then increased future victimization. The implications of these prospective findings for interventions are considered. Aggr. Behav. 9999:XX–XX, 2015. © 2015 Wiley Periodicals, Inc.
    Aggressive Behavior 01/2015; 41(2). DOI:10.1002/AB.21580 · 2.27 Impact Factor
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    ABSTRACT: Parental educational expectations have been associated with children's educational attainment in a number of long-term longitudinal studies, but whether this relationship is causal has long been debated. The aims of this prospective study were twofold: 1) test whether low maternal educational expectations contributed to failure to graduate from high school; and 2) compare the results obtained using different strategies for accounting for confounding variables (i.e. multivariate regression and propensity score matching). The study sample included 1,279 participants from the Quebec Longitudinal Study of Kindergarten Children. Maternal educational expectations were assessed when the participants were aged 12 years. High school graduation - measuring educational attainment - was determined through the Quebec Ministry of Education when the participants were aged 22-23 years. Findings show that when using the most common statistical approach (i.e. multivariate regressions to adjust for a restricted set of potential confounders) the contribution of low maternal educational expectations to failure to graduate from high school was statistically significant. However, when using propensity score matching, the contribution of maternal expectations was reduced and remained statistically significant only for males. The results of this study are consistent with the possibility that the contribution of parental expectations to educational attainment is overestimated in the available literature. This may be explained by the use of a restricted range of potential confounding variables as well as the dearth of studies using appropriate statistical techniques and study designs in order to minimize confounding. Each of these techniques and designs, including propensity score matching, has its strengths and limitations: A more comprehensive understanding of the causal role of parental expectations will stem from a convergence of findings from studies using different techniques and designs.
    PLoS ONE 01/2015; 10(3):e0119638. DOI:10.1371/journal.pone.0119638 · 3.53 Impact Factor
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    ABSTRACT: Background Antisocial personality disorder (ASPD) is characterised by elevated impulsive aggression and increased risk for criminal behaviour and incarceration. Deficient activity of the monoamine oxidase A (MAOA) gene is suggested to contribute to serotonergic system dysregulation strongly associated with impulsive aggression and antisocial criminality. Aims To elucidate the role of epigenetic processes in altered MAOA expression and serotonin regulation in a population of incarcerated offenders with ASPD compared with a healthy non-incarcerated control population. Method Participants were 86 incarcerated participants with ASPD and 73 healthy controls. MAOA promoter methylation was compared between case and control groups. We explored the functional impact of MAOA promoter methylation on gene expression in vitro and blood 5-HT levels in a subset of the case group. Results Results suggest that MAOA promoter hypermethylation is associated with ASPD and may contribute to downregulation of MAOA gene expression, as indicated by functional assays in vitro, and regression analysis with whole-blood serotonin levels in offenders with ASPD. Conclusions These results are consistent with prior literature suggesting MAOA and serotonergic dysregulation in antisocial populations. Our results offer the first evidence suggesting epigenetic mechanisms may contribute to MAOA dysregulation in antisocial offenders. Royal College of Psychiatrists.
    The British journal of psychiatry: the journal of mental science 12/2014; DOI:10.1192/bjp.bp.114.144964 · 7.34 Impact Factor
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    ABSTRACT: DNA methylation patterns are characterized by highly conserved developmental programs, but allow for divergent gene expression resulting from stochastic epigenetic drift or divergent environments. Genome-wide methylation studies in monozygotic (MZ) twins are providing insight into the extent of epigenetic variation that occurs, irrespective of genotype. However, little is known about the variability of DNA methylation patterns in adolescence, a period involving significant and rapid physical, emotional, social, and neurodevelopmental change. Here, we assessed genome-wide DNA methylation using the 450 K Illumina BeadChip in a sample of 37 MZ twin pairs followed longitudinally since birth to investigate: 1) the extent of variation in DNA methylation in identical genetic backgrounds in adolescence and; 2) whether these variations are randomly distributed or enriched in particular functional pathways. We also assessed stability of DNA methylation over 3-6 months to distinguish stable trait-like and variable state-like genes. A pathway analysis found high within-pair variability in genes associated with development, cellular mechanisms, tissue and cell morphology, and various disorders. Test-retest analyses performed in a sub-sample of 8 twin pairs demonstrated enrichment in gene pathways involved in organismal development, cellular growth and proliferation, cell signaling, and particular disorders. The variability found in functional gene pathways may plausibly underlie phenotypic differences in this adolescent MZ twin sample. Furthermore, we assessed stability of methylation over 3-6 months and found that some genes were stable while others were unstable, suggesting that the methylome remains dynamic in adolescence and that dynamic sites tend to be organized in certain gene pathways.
    Epigenetics: official journal of the DNA Methylation Society 10/2014; 9(10):1410-22. DOI:10.4161/15592294.2014.970060 · 5.11 Impact Factor
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    ABSTRACT: Background Little is known about the associations between self-reported offending and official offending whilst considering different types of offences.AimsThe aims of the present study are to identify developmental trajectories of self-reported violent and nonviolent offending (SRVO; SRNVO) and to examine their associations with official violent and nonviolent offences (as juveniles and adults).Methods Developmental trajectories of SRVO and SRNVO from 11 to 17 years of age were estimated with data from the Montreal Longitudinal and Experimental Study, a prospective longitudinal study of 1037 boys from disadvantaged neighbourhoods.ResultsFive trajectories of SRVO (i.e. Chronic, Desisting, Delayed, Moderate and Low) and three trajectories of SRNVO (Chronic, Moderate and Low) were identified. Chronic, Desisting and Delayed trajectories of SRVO were associated with violent and nonviolent official offending in adolescence and early adulthood, over and above the trajectories of SRNVO. In comparison, trajectories of SRNVO were weakly and inconsistently associated with official offending, once controlling for their overlap with trajectories of SRVO.Conclusions Individuals on high trajectories of violent offending during adolescence are most at risk for being exposed to the justice system both concurrently and longitudinally. Differentiating violent and nonviolent offending can help resolve part of the discordance between self-reported and official offending. Copyright © 2014 John Wiley & Sons, Ltd.
    Criminal Behaviour and Mental Health 10/2014; 24(4). DOI:10.1002/cbm.1935 · 1.28 Impact Factor
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    ABSTRACT: Proactive aggression (PA) describes an instrumental behavior that is goal-oriented, whereas reactive aggression (RA) refers to an angry or frustrated aggressive response to a real or perceived threat. Little is known about the respective roles of genetic (G) and environmental (E) factors associated with PA and RA during childhood. The objectives of this study were to investigate a) the G-E etiology of the commonality between PA and RA and b) the presence of G or E components specific to PA or RA throughout childhood (i.e., from 6 to 12 years of age). Participants were 254 monozygotic and 413 dizygotic pairs. Teacher reports of PA and RAwere obtained at 6, 7, 9, 10 and 12 years of age. Throughout childhood, genetic factors accounted for most of the common variance between PAand RA, as well as their specificity. Shared environment played no role. Specifically, genetic factors common to PA and RA explained between 39% and 45% of the variance in PA, and between 27% and 42% of the variance in RA. Genetic factor also uniquely accounted for only but a small percentage (9% at 6 years and 3% at 9 years old) of the variation in PA. As for RA, three distinctive genetic factors contributed to phenotypic variation throughout childhood and explained between 12% and 22% of variance. Dynamic genetic factors accounted for the commonality in PA and RA, and for the specificity of RA. Few genetic factors were unique to PA; in contrast, for RA, an early, specific and persistent genetic factor was found alongside new genetic factors that appeared at later ages. These results challenge theoretical models that focus primarily on the effects of environmental factors in the etiology of reactive and proactive aggression.
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    ABSTRACT: The goal of the study was to identify a group of adolescent "slow readers" and retrospectively test which ADHD symptoms and neuropsychological processes were affected at 8 years of age.
    Archives of Clinical Neuropsychology 09/2014; 29(6):546. DOI:10.1093/arclin/acu038.115 · 1.92 Impact Factor
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    ABSTRACT: This study examined sibling influence over gambling involvement and delinquency in a sample of 628 twins (151 male dyads, 163 female dyads). Self-reports of gambling involvement and delinquency were collected for each twin at ages 13, 14 and 15 years. Results revealed evidence of between-twin influence. Higher levels of an adolescent's delinquency predicted an increase in his or her co-twin's delinquency from age 13 to age 14 and from age 14 to age 15. In contrast, gambling behavior was unaffected by the co-twin's gambling involvement. Within-twins, higher initial levels of delinquency predicted a subsequent increase in gambling behavior from age 13 to age 14 and again from age 14 to age 15, and higher initial levels of gambling involvement predicted an increase in delinquency from age 14 to age 15. Between and within siblings effects are discussed in light of the scant literature on (a) sibling influence on gambling, and (b) the links between gambling and delinquency.
    Journal of Gambling Behavior 07/2014; DOI:10.1007/s10899-014-9487-9 · 1.28 Impact Factor

Publication Stats

9k Citations
998.58 Total Impact Points

Institutions

  • 1995–2015
    • McGill University
      • • Department of Psychiatry
      • • Department of Psychology
      Montréal, Quebec, Canada
  • 1991–2015
    • Université de Montréal
      • School of Psycho-Education
      Montréal, Quebec, Canada
  • 2004–2013
    • Université du Québec à Montréal
      • • Department of Psychology
      • • Department of Sexology
      Montréal, Quebec, Canada
  • 1999–2013
    • Laval University
      • School of Psychology
      Québec, Quebec, Canada
  • 2011
    • CHU Sainte-Justine
      Montréal, Quebec, Canada
    • Université René Descartes - Paris 5
      Lutetia Parisorum, Île-de-France, France
  • 2008–2010
    • Radboud University Nijmegen
      • Behavioural Science Institute
      Nijmegen, Provincie Gelderland, Netherlands
    • University College London
      Londinium, England, United Kingdom
  • 2006–2010
    • VU University Amsterdam
      • • Department of Clinical Psychology
      • • Department of Developmental Psychology
      Amsterdam, North Holland, Netherlands
  • 1988–2007
    • Université du Québec
      Quebec City, Quebec, Canada
  • 2005
    • The University of Winnipeg
      • Department of Economics
      Winnipeg, Manitoba, Canada
  • 2003
    • University of New Mexico
      • Department of Sociology
      Albuquerque, NM, United States
  • 2002
    • Concordia University Montreal
      Montréal, Quebec, Canada
  • 2000–2001
    • Hôpital du Sacré-Coeur de Montréal
      • Center for Advanced Research in Sleep Medicine
      Montréal, Quebec, Canada
    • University of Jyväskylä
      • Department of Psychology
      Jyväskylä, Province of Western Finland, Finland
  • 1989
    • University of Hull
      Kingston upon Hull, England, United Kingdom