Frank Vitaro

Developmental Trajectories of Childhood Disruptive Behaviors and Adolescent Delinquency: A Six-Site, Cross-National Study

This study used data from 6 sites and 3 countries to examine the developmental course of physical aggression in childhood and to analyze its linkage to violent and nonviolent offending outcomes in adolescence. The results indicate that among boys there is continuity in problem behavior from childhood to adolescence and that such continuity is especially acute when early problem behavior takes the form of physical aggression. Chronic physical aggression during the elementary school years specifically increases the risk for continued physical violence as well as other nonviolent forms of delinquency during adolescence. However, this conclusion is reserved primarily for boys, because the results indicate no clear linkage between childhood physical aggression and adolescent offending among female samples despite notable similarities across male and female samples in the developmental course of physical aggression in childhood.

The power of friendship: protection against an escalating cycle of peer victimization

This study examined 2 aspects of friendship (presence and perceived qualities of a best friend) as moderators of behavioral antecedents and outcomes of peer victimization. A total of 393 children (188 boys and 205 girls) in the 4th and 5th grades (mean age = 10 years 7 months) participated during each of 2 waves of data collection in this 1-year longitudinal study. Results indicated that teacher-reported internalizing and externalizing behaviors predicted increases in peer-reported victimization, but the relation of internalizing behaviors to increases in victimization was attenuated for children with a protective friendship. Victimization predicted increases in internalizing and externalizing behaviors but only for children without a mutual best friendship. Results highlight the importance of peer friendships in preventing an escalating cycle of peer abuse.

Reactively and proactively aggressive children: antecedent and subsequent characteristics

BACKGROUND Reactive and proactive subtypes of aggressive 10-11-12-year-old children were compared with non-aggressive children to examine whether the two forms of aggression were differentially related to antecedent and subsequent measures. METHOD A large community sample of boys and girls was used. Reactive and proactive aggression was measured through teacher ratings when the children were 10, 11 and 12 years old. Antecedent measures were age 6 temperament and behavioral dispositions; subsequent measures were age 13 delinquency and depressive symptoms. RESULTS Results indicated that reactive and proactive children had distinctive profiles on antecedent and subsequent measures. CONCLUSIONS We conclude that children characterized by reactive or proactive aggression differ on several dimensions of personal functioning, and that reactive and proactive aggression are distinct forms of aggression, although both co-occur in a large proportion of aggressive children.

Development of parasomnias from childhood to early adolescence.

Objectives. This study examines the prevalence and developmental changes of parasomnias and assesses gender differences, relationships between parasomnias, and associations with anxiety and family adversity using data collected during the course of a longitudinal study of a representative sample of children from Québec. Method. The present analyses are based on results available for 664 boys and 689 girls for whom mothers have completed questions concerning demographics, parasomnias, and anxiety level. For the prevalence and developmental aspects of parasomnias, prospective data were collected at annual intervals from 11 to 13 years old and retrospective data for the period between ages 3 and 10 years were collected when the children were 10 years old. Results. Somniloquy, leg restlessness, and sleep bruxism are the most frequent parasomnias. More girls were afflicted with leg restlessness, while enuresis and somniloquy were more common in boys. High anxiety scores were found in children suffering from night terrors, somniloquy, leg restlessness, sleep bruxism, and body rocking. Parasomnias were unrelated to the index of family adversity. Conclusions. Although sleepwalking, night terrors, enuresis, and body rocking dramatically decreased during childhood, somniloquy, leg restlessness, and sleep bruxism were still highly prevalent at age 13 years, paralleling results found in adults. Sleepwalking, night terrors, and somniloquy are conditions often found together. The only robust gender difference was for enuresis. High anxiety scores in parasomnias are reported for the first time in a large, controlled study. Sociodemographic variables do not seem to play a major role in the occurrence of parasomnias.

Reactive and Proactive Aggression Differentially Predict Later Conduct Problems

This study tested whether proactive and reactive aggression were differently predictive of later externalizing problems such as delinquency and DSM-related disruptive behaviors (i.e. oppositional defiant and conduct disorders). It also tested whether these two subtypes of aggressive behaviors interacted in predicting externalizing problems. A community sample of low SES boys participated in the study. Proactive and reactive aggression were rated by teachers when boys were 12 years old. Delinquency, oppositional disorders, and conduct disorders were assessed during mid-adolescence. Proactive but not reactive aggression predicted delinquency and disruptive behaviors. Moreover, high levels of reactive aggression weakened the link between proactive aggression and delinquency. Reactive aggression, however, did not moderate the link between proactive aggression and disruptive behaviors. We conclude that reactive and proactive aggression are two types of aggressive behaviors with different predictive abilities. We also offer tentative explanations to account for the present findings.

Development of sleep patterns in early adolescence

This study examines the developmental changes of sleep patterns as a function of gender and puberty and assesses the prevalence of sleep habits and sleep disturbances in early adolescence. It also investigates the relationship between sleep patterns, sleep habits and difficulty falling asleep and nocturnal awakenings. The present analyses are based on results available for 588 boys and 558 girls for whom mothers completed questions concerning demographics and sleep at annual intervals when their child was aged 10–13 years. The results indicated that nocturnal sleep times decreased, bedtimes were delayed and differences between weekend and school day sleep schedules progressively increased with age. Gender and puberty were both associated with the timing of sleep on weekends. Girls presented longer weekend time in bed (TIB) and later weekend wake time than boys. Similarly, subjects with higher pubertal status showed longer weekend TIB and later weekend wake time than subjects with lower pubertal status. Difficulty falling asleep was associated with later weekend wake time and with sleeping with a night light. In conclusion, the gender differences commonly reported in adolescents’ sleep patterns are most likely explained by girls’ higher pubertal status. This study emphasizes the link between puberty and a putative physiological need for more sleep, in presence of a general reduction of sleep times during adolescence. From age 10–13 years, the delay and lengthening of the sleep period on weekends in comparison to schooldays is associated with difficulty falling asleep.

Reactive and Proactive Aggression: Predictions to Physical Violence in Different Contexts and Moderating Effects of Parental Monitoring and Caregiving Behavior

This study aimed at (a) comparing the links of proactive and reactive aggression at 13 years of age to delinquency-related violence and dating violence at ages 16 and 17, and (b) examining the moderating effects of parental supervision, and mothers and fathers warmth and caregiving behaviors on these links. Based on a sample of 525 Caucasian boys, the results showed that proactive aggression uniquely predicted delinquency-related violence, whereas reactive aggression uniquely predicted later dating violence. The relation between proactive aggression and delinquency-related violence, however, was moderated by parental supervision. The relation between reactive aggression and dating violence was moderated by mothers warmth and caregiving behavior. The implications of the findings for the theoretical and practical distinction between proactive and reactive aggression are discussed.

Subtypes of aggressive behaviors: A developmental perspective

Aggressive behaviors in children and adolescents have undergone important conceptual and definitional modifications in the past two decades. In particular, subtypes of aggression have been proposed that separate the form and the function of the aggressive behaviors (i.e., social vs. physical aggression; reactive vs. proactive aggression). Moreover, new methodological tools have been developed to examine the developmental course of these subtypes, as well as their correlates. These conceptual and methodological innovations, in turn, have introduced new views of the development of aggressive behaviors. These “new views” contrast with more traditional perspectives about the evolution of aggressive behaviors from infancy to young adulthood, particularly with respect to the existence of individuals who begin to become aggressive by adolescence only. This article gives an overview of these definitional, conceptual, and methodological innovations. It also tries to reconcile different views about the development of aggressive behaviors from infancy through early adulthood. Theoretical and practical/clinical implications are also reviewed. The conclusion describes an integrative framework and identifies possible areas of research for the future.

Kindergarten Disruptive Behaviors, Protective Factors, and Educational Achievement by Early Adulthood.

This study examined whether 2 aspects of disruptive behaviors (i.e., hyperactivity-inattention and aggressiveness-opposition) observed in kindergarten predict noncompletion of high school by early adulthood. Also investigated was whether other personal characteristics such as anxiety or prosociality as well as parent child-rearing attitudes and teacher management style exert a compensatory or protective role with respect to these predictive links. A community sample of 4,330 children participated in this study. Results showed that hyperactivity-inattention made a stronger contribution to predicting noncompletion of high school than did aggressiveness-opposition. However, prosociality and 2 parental child-rearing aspects (i.e., pleasure and discipline) played a compensatory role in this process. Theoretical and preventive implications of these results are stressed in the discussion.

The development of impulsivity, fearfulness, and helpfulness during childhood: patterns of consistency and change in the trajectories of boys and girls

BACKGROUND The objective of the present study was to describe the development of boys and girls during the elementary-school years on three dimensions that conceptually and empirically represent risk for maladjustment. METHOD Every year between kindergarten and grade six, teachers rated the impulsivity, fearfulness, and helpfulness dimensions among a sample of 1,865 children representative of kindergarten boys and girls in the province of Quebec (Canada) in 1986-87. A group-based trajectory method was used to 1) identify groups of boys and girls following distinct-level trajectories of behaviours (on each dimension) during the elementary-school years; 2) estimate the proportion of children in each of the identified trajectory groups; and 3) estimate the patterns of consistency and variations in trajectories. RESULTS The results indicated that the best models comprised three distinct-level trajectory groups on fearfulness and helpfulness (a low, moderate, and high group) and four distinct-level trajectory groups on impulsivity. The helpfulness and fearfulness trajectory groups were generally more stable than the impulsivity groups. The broad patterns of development were similar across sexes. However, there were more boys on the higher impulsivity trajectories and low helpfulness trajectory, while there were more girls on the high fearfulness trajectory. CONCLUSION We found that behavioural consistency over middle childhood varied across trajectory groups and across dimensions, and we identified sex differences in the distribution of children in the different trajectory groups that may reflect gender-specific risks for psychopathology.