Childhood behavior problems and adverse economic outcomes: a 30-year population-based study of intergenerational income mobility.

BACKGROUND: The objectives of this study were to (a) assess the associations between early behavioral problems and intergenerational income mobility (i.e., the degree to which income status is transmitted from one generation to the next), (b) verify whether these associations are moderated by child sex, and (c) explore indirect effects of early behavioral problems on income mobility via high school graduation. METHODS: Data were drawn from the Quebec Longitudinal Study of Kindergarten Children (n = 3,020; 49.17% girls). Participants were followed from age 6 to 37 years. Measures included parents' and teachers' ratings of behavioral problems at age 6 years as well as participants' (ages 30-35 years) and their parents' (when participants were aged 10-19 years) income data obtained from tax return records. Regression models were used to predict upward and downward mobility (i.e., increased or decreased income status from one generation to the next) from attention-deficit/hyperactivity problems, conduct/opposition problems, depression/anxiety problems, prosociality, and the quality of children's relationship with their caregiver. Two-way interaction effects between behavioral problems and child sex were examined and indirect effect models including high school graduation as a mediator of these associations were conducted. RESULTS: Despite their higher educational attainment, females had lower incomes and experienced lower upward (but higher downward) income mobility than males. For both females and males, higher levels of attention-deficit/hyperactivity and conduct/opposition problems were associated with decreased odds of upward mobility, whereas higher levels of attention-deficit/hyperactivity were associated with increased odds of downward mobility. Attention-deficit/hyperactivity problems, conduct/opposition problems as well as low prosociality were associated with lower educational attainment (no high school diploma), which in turn was associated with increased odds of downward mobility. CONCLUSIONS: Results highlight the importance of providing intensive support to children with early behavioral problems as a means of improving educational attainment and intergenerational income mobility.

The social and economic impact of the Montreal Longitudinal and Experimental Study.

BACKGROUND: The effectiveness of early prevention programmes and their viability as a public policy option have increasingly caught the attention of scholars and policymakers. Given the implementation costs of such programmes, it is important to assess whether they achieved anticipated objectives and whether they made efficient use of taxpayer money. AIM: To discuss the social and economic impact of a 2-year randomised intervention aimed to improve social skills and self-control (i.e., non-cognitive skills) among disruptive boys from low-income neighbourhoods in Montreal. METHOD: We review findings from published studies documenting the impact of the intervention at different stages of the life course, as well as its cost-effectiveness and cost-benefit. RESULTS: The intervention improved behavioural indicators throughout adolescence and eventually led to greater high school graduation rates, reduced crime, and better labour market outcomes in adulthood. Importantly, the prevention programme generated considerable returns to taxpayer investments. CONCLUSION: Findings from the Montreal Longitudinal Experimental Study have been well-received and have contributed to an early prevention 'awakening' in Quebec and elsewhere.

Association of Childhood Externalizing, Internalizing, and Comorbid Symptoms With Long-term Economic and Social Outcomes.

Importance: Little is known about the long-term economic and social outcomes for children with longitudinally assessed comorbid externalizing and internalizing symptoms, especially compared with children with externalizing symptoms or internalizing symptoms only. Objective: To examine the association between childhood trajectories of externalizing, internalizing, and comorbid symptoms and long-term economic and social outcomes. Design, Setting, and Participants: A 32-year prospective cohort study linked with administrative data was conducted in school-aged participants aged 6 to 12 years in the Québec Longitudinal Study of Kindergarten Children (N = 3017) followed up from 1985 to 2017. Data analysis was conducted between August 1, 2021, and March 31, 2022. Exposures: Teacher-rated behavioral symptoms were used to categorize children from age 6 to 12 years into developmental profiles using group-based trajectory modeling. Main Outcomes and Measures: Multivariable regression models were used to test the association between childhood symptom profile group and adult employment earnings, welfare receipt, intimate partnership status, and having children living in the household. Participant sex, IQ, and socioeconomic background were adjusted for. Results: Of 3017 participants in this sample, 1594 (52.8%) were male and 1423 (47.2%) were female. Per confidentiality rules established by Statistics Canada, income variables were rounded to base 100 and count variables were rounded to base 10; the mean (SD) age was 37 (0.29) years at follow-up. Four symptom profiles were identified: no/low (n = 1369 [45.4%]), high externalizing (882 [29.2%]), high internalizing (354 [11.7%]), and comorbid (412 [13.7%]) symptoms. Compared with the no/low symptom profile, participants in the high externalizing-only profile earned $5904 (95% CI, -$7988 to -$3821) less per year and had 2.0 (95% CI, 1.58-2.53) times higher incidence of welfare receipt, while participants in the high internalizing group earned $8473 (95% CI, -$11 228 to -$5717) less per year, had a 2.07 (95% CI, 1.51-2.83) higher incidence of welfare receipt, and had a lower incidence of intimate partnership (incident rate ratio [IRR], 0.89; 95% CI, 0.80-0.99). Participants in the comorbid profile fared especially poorly: they earned $15 031 (95% CI, -$18 030 to -$12 031) less per year, had a 3.79 (95% CI, 2.75-5.23) times higher incidence of annual welfare receipt, and were less likely to have an intimate partner (IRR, 0.71; 95% CI, 0.63-0.79) and children living in the household (IRR, 0.86; 95% CI, 0.80-0.92). Estimated lost earnings over a 40-year working career were $140 515 for the high externalizing, $201 657 for the high internalizing, and $357 737 for the comorbid profiles. Conclusions and Relevance: In this cohort study, children exhibiting sustained childhood high externalizing, high internalizing, or comorbid symptoms were at increased risk of poor economic and social outcomes into middle age. These findings suggest that children exhibiting comorbid problems were especially vulnerable and that early detection and support are indicated.

The phenotypic associations and gene-environment underpinnings of socioeconomic status and diurnal cortisol secretion in adolescence.

While converging evidence suggests that both environmental and genetic factors underlie variations in diurnal cortisol, the extent to which these sources of influence vary according to socioeconomic status (SES) has seldom been investigated, particularly in adolescence. To investigate whether a distinct genetic and environmental contribution to youth's diurnal cortisol secretion emerges according to family SES and whether the timing of these experiences matters. Participants were 592 twin pairs, who mostly came from middle-income and intact families and for whom SES was measured in childhood and adolescence. Diurnal cortisol was assessed at age 14 at awakening, 30 min later, in the afternoon and evening over four nonconsecutive days. SES-cortisol phenotypic associations were specific to the adolescence period. Specifically, higher awakening cortisol levels were detected in wealthier backgrounds, whereas higher cortisol awakening response (CAR) and diurnal changes were present at both ends of the SES continuum. Moreover, smaller genetic contributions emerged for awakening cortisol in youth from poorer compared to wealthier backgrounds. The results suggest that the relative contribution of inherited factors to awakening cortisol secretion may be enhanced or suppressed depending on the socio-family context, which may help to decipher the mechanisms underlying later adjustment.

Trajectories of adolescent poly-substance use and their long-term social and economic outcomes for males from low-income backgrounds.

Substance abuse is a significant public health concern that disproportionately burdens males and low-income communities. This study examined (1) longitudinal profiles of male adolescent poly-substance use and (2) their association with social and economic participation across early adulthood. Drawing on a cohort of males (n = 890) from low-income neighborhoods, we used group-based multi-trajectory modeling to identify profiles of poly-substance use (alcohol, tobacco, cannabis, illicit drugs) from age 13-17 years. Regression models were used to link substance use profiles to high school graduation, criminal convictions, personal and household earnings, welfare receipt and partnership from age 19-37 years, obtained from administrative records. Child IQ, family adversity and behavioral problems were adjusted for. Four poly-substance use profiles were identified: abstinent (n = 128, 14.4%), late-onset (n = 412, 46.5%), mid-onset (n = 249, 28.1%), and early-onset (n = 98, 11.1%). Relative to the late-onset (reference) group, participants in the early-onset profile were 3.0 times (95%CI = 1.68-5.53) more likely to have left school without a diploma, 2.7 times (95% CI = 1.56-4.68) more likely to have a criminal conviction by age 24 years, earned 10,185 USD less (95% CI = - 15,225- - 5144) per year at age 33-37 years and had 15,790 USD lower (95% CI = - 23,378- - 8218) household income at age 33-37 years, a 1.3 times (95%CI = 1.15-1.57) higher incidence of annual welfare receipt and a 24% (95% CI = 5-40) lower incidence of marriage/cohabitation from age 18-35 years. We show that adolescent-onset poly-substance use by age 13 is associated with poor social and economic outcomes. Delaying the onset of substance use and reducing exposure to additional substance classes has potential for high societal cost savings.

Cumulative exposure to socioeconomic and psychosocial adversity and hair cortisol concentration: A longitudinal study from 5 months to 17 years of age.

BACKGROUND: Exposure to early adversity has been associated with long-lasting risks for poor health and functioning. Prior research suggests that the hypothalamic-pituitary-adrenal (HPA) axis, and its main end-product glucocorticoid hormone cortisol, may be at play. This study tested whether an index of cumulative socioeconomic and psychosocial adversity assessed prospectively, from infancy to adolescence, was associated with hair cortisol concentration (HCC), and if this association differed by sex. METHODS: The sample comprised 556 adolescents (42.0% males) who provided hair for cortisol measurement at 17 years of age. Adversity indicators (young and single motherhood, low socioeconomic status (SES), maternal alcohol use, hostile-reactive parenting, and depressive symptoms, as well as peer victimization and neighborhood dangerousness) were repeatedly reported by mothers or youths between the ages of 5 months and 15 years. RESULTS: Chronic adversity was non-linearly associated with HCC; youth exposed to lower and higher levels of adversity had moderate-to-higher HCC compared to lower HCC noted in participants with moderate levels of adversity, for both males and females. None of the indicators taken separately, except the perception of neighborhood dangerousness, were significantly associated with HCC. CONCLUSION: Our findings support the hypothesis that HPA axis activity varies according to cumulative adversity, albeit non-linearly, which may bear consequences for later health and functioning.

Long-term economic and social outcomes of youth suicide attempts.

BACKGROUND: Youth who attempt suicide are more at risk for later mental disorders and suicide. However, little is known about their long-term socioeconomic outcomes. AIMS: We investigated associations between youth suicide attempts and adult economic and social outcomes. METHOD: Participants were drawn from the Quebec Longitudinal Study of Kindergarten Children (n = 2140) and followed up from ages 6 to 37 years. Lifetime suicide attempt was assessed at 15 and 22 years. Economic (employment earnings, retirement savings, welfare support, bankruptcy) and social (romantic partnership, separation/divorce, number of children) outcomes were assessed through data linkage with government tax return records obtained from age 22 to 37 years (2002-2017). Generalised linear models were used to test the association between youth suicide attempt and outcomes adjusting for background characteristics, parental mental disorders and suicide, and youth concurrent mental disorders. RESULTS: By age 22, 210 youths (9.8%) had attempted suicide. In fully adjusted models, youth who attempted suicide had lower annual earnings (average last 5 years, US$ -4134, 95% CI -7950 to -317), retirement savings (average last 5 years, US$ -1387, 95% CI -2982 to 209), greater risk of receiving welfare support (risk ratio (RR) = 2.05, 95% CI 1.39 to 3.04) and were less likely to be married/cohabiting (RR = 0.82, 95% CI 0.73 to 0.93), compared with those who did not attempt suicide. Over a 40-year working career, the loss of individual earnings attributable to suicide attempts was estimated at US$98 384. CONCLUSIONS: Youth who attempt suicide are at risk of poor adult socioeconomic outcomes. Findings underscore the importance of psychosocial interventions for young people who have attempted suicide to prevent long-term social and economic disadvantage.

Child Care Attendance and Educational and Economic Outcomes in Adulthood.

OBJECTIVES: To test associations between onset of formal child care (in infancy or as a toddler), high school graduation, and employment earnings from ages 18 to 35 years. METHODS: A 30-year prospective cohort follow-up study, with linkage to government administrative databases (N =3020). Exposure included formal child care, if any, by accredited caregivers in centers or residential settings at ages 6 months and 1, 1.5, 2, 3, and 4 years. A propensity score analysis was conducted to control for social selection bias. RESULTS: Of 2905 participants with data on child care use, 59.4% of male participants and 78.5% of female participants completed high school by age 22 to 23. Mean income at last follow-up (n = 2860) was $47 000 (Canadian dollars) (SD = 37 700) and $32 500 (SD = 26 800), respectively. Using group-based trajectory modeling, we identified 3 groups: formal child care onset in infancy (∼6 months), formal child care onset as a toddler (after 2.5 years), and never exposed. After propensity score weighting, boys with child care started in infancy had greater odds of graduating than those never exposed (odds ratio [OR] 1.39; 95% confidence interval [CI]: 1.18-1.63; P < .001). Boys attending child care had reduced odds of low income as young adults (infant onset: OR 0.60 [95% CI: 0.46-0.84; P < .001]; toddler onset: OR 0.63 [95% CI: 0.45-0.82; P < .001]). Girls' graduation rates and incomes revealed no significant association with child care attendance. CONCLUSIONS: For boys, formal child care was associated with higher high school completion rates and reduced risk of adult poverty. Benefits for boys may therefore extend beyond school readiness, academic performance, and parental workforce participation.

Inattention in boys from low-income backgrounds predicts welfare receipt: a 30-year prospective study.

BACKGROUND: Childhood disruptive behaviors are highly prevalent and associated with adverse long-term social and economic outcomes. Trajectories of welfare receipt in early adulthood and the association of childhood behaviors with high welfare receipt trajectories have not been examined. METHODS: Boys (n = 1000) from low socioeconomic backgrounds were assessed by kindergarten teachers for inattention, hyperactivity, aggression, opposition, and prosociality, and prospectively followed up for 30 years. We used group-base trajectory modeling to estimate trajectories of welfare receipt from age 19-36 years using government tax return records, then examined the association between teacher-rated behaviors and trajectory group membership using mixed effects multinomial regression models. RESULTS: Three trajectories of welfare receipt were identified: low (70.8%), declining (19.9%), and chronic (9.3%). The mean annual personal employment earnings (US$) for the three groups at age 35/36 years was $36 500 (s.d. = $24 000), $15 600 (s.d. = $16 275), and $1700 (s.d. = $4800), respectively. Relative to the low welfare receipt group, a unit increase in inattention (mean = 2.64; s.d. = 2.32, range = 0-8) at age 6 was associated with an increased risk of being in the chronic group (relative risk ratio; RRR = 1.16, 95% CI 1.03-1.31) and in the declining group (RRR = 1.13, 95% CI 1.03-1.23), after adjustment for child IQ and family adversity, and independent of other behaviors. Family adversity was more strongly associated with trajectories of welfare receipt than any behavior. CONCLUSIONS: Boys from disadvantaged backgrounds exhibiting high inattention in kindergarten are at elevated risk of chronic welfare receipt during adulthood. Screening and support for inattentive behaviors beginning in kindergarten could have long-term social and economic benefits for individuals and society.

Early childhood child care and disruptive behavior problems during adolescence: a 17-year population-based propensity score study.

BACKGROUND: Child-care services during early childhood provide opportunities for social interactions that may facilitate children's learning of acceptable social behaviors. Furthermore, they may reduce exposure to family adversity for some children. The aim of this study was to determine whether intensity of exposure to child-care services prior to age 5 years has a beneficial effect on disruptive behavior problems during adolescence, and whether the effect is more pronounced for children from low socioeconomic families. METHODS: N = 1,588 participants from the Québec Longitudinal Study of Child Development were assessed 14 times from 5 months to 17 years. Intensity of child-care exposure was measured from 5 months to 5 years of age. Main outcomes were self-reported physical aggression and opposition from age 12 to 17 years. Family socioeconomic status (SES) was measured at 5 months. Factors explaining differences in child-care use were controlled using propensity score weights (PSW). RESULTS: Children exposed to moderate-intensity child-care services (part-time child-care services before 1½ years and full time afterward) reported lower levels of physical aggression (d = -.11, p = .056) and opposition (d = -.14, p = .029) during adolescence compared to children exposed to low-intensity child-care services. A significant child care by SES interaction (p = .017) for physical aggression indicated that the moderate-intensity child-care effect was specific to children from low SES families (d = -.36, p = .002). No interaction with socioeconomic status was found for opposition. CONCLUSIONS: Moderate-intensity child-care services from infancy to school entry may prevent disruptive behavior during adolescence, especially for disadvantaged children.

Are Traumatic Brain Injuries Associated With Criminality After Taking Account of Childhood Family Social Status and Disruptive Behaviors?

OBJECTIVE: The authors aimed to elucidate the links between traumatic brain injuries (TBIs) and criminal convictions in a sample of 724 Canadian males with and without criminal records followed up to age 24. METHODS: Prospectively collected data were analyzed to determine whether prior TBIs predicted subsequent criminal convictions after taking account of family social status (FSS) and childhood disruptive behaviors. At age 24, diagnoses of TBIs were extracted from health records and convictions from official criminal records. In childhood, teachers rated disruptive behaviors and parents reported FSS. RESULTS: Proportionately more individuals with offender status than nonoffender status sustained a TBI from age 18 to age 24 but not before age 18. Individuals with offender status who had sustained a TBI before and after their first conviction were similar in numbers, were raised in families of low social status, and presented high levels of disruptive behaviors from age 6 to age 12. When FSS and childhood disruptive behaviors were included in multivariable regression models, sustaining a prior TBI was not associated with an increased risk of juvenile convictions for any type of crime, for violent crimes, for convictions for any crime or violent crime from age 18 to age 24, or for a first crime or a first violent crime from age 18 to age 24. CONCLUSIONS: Among males, there was no evidence that prior TBIs were associated with an increased risk of subsequent criminal convictions from age 12 to age 24 when taking account of FSS and childhood disruptive behaviors, although these latter factors may be associated with an increased prevalence of TBIs among adult offenders.

The moderating role of peer norms in the associations of social withdrawal and aggression with peer victimization.

This study examined the moderating role of classroom injunctive norms salience regarding social withdrawal and regarding aggression in the longitudinal association between these behaviors and peer victimization. A total of 1,769 fourth through sixth graders (895 girls, M = 10.25 years, SD = 1.03) from 23 schools (67 classrooms) completed a peer nomination inventory in the fall (T1) and spring (T2) of the same academic year. Participants circled the name of each student who fit the description provided for social withdrawal, aggression, and peer victimization at T1 and T2. The salience of injunctive norms was sex-specific and operationalized by the extent to which children displaying the behavior were socially rewarded or sanctioned by their classmates. Generalized estimation equations (GEE) showed that the association between social withdrawal at T1 and peer victimization at T2 was moderated by injunctive norms. Social withdrawal at T1 was positively associated with peer victimization at T2 in classrooms where injunctive norms for this behavior were salient and unfavorable, as well as in classrooms where injunctive norms for aggression were salient and favorable, albeit for girls only. The association between aggression at T1 and peer victimization at T2 was also moderated by the injunctive norms regarding this behavior. Aggressive children were less likely to be victimized in classrooms where this behavior was rewarded. These results support bullying interventions that target factors related to the larger peer context, including social norms. (PsycINFO Database Record

Psychometric properties of the Mental Health and Social Inadaptation Assessment for Adolescents (MIA) in a population-based sample.

We report on the psychometric properties of the Mental Health and Social Inadaptation Assessment for Adolescents (MIA), a self-report instrument for quantifying the frequency of mental health and psychosocial adaptation problems using a dimensional approach and based on the DSM-5. The instrument includes 113 questions, takes 20-25 minutes to answer, and covers the past 12 months. A population-based cohort of adolescents (n = 1443, age = 15 years; 48% males) rated the frequency at which they experienced symptoms of Attention Deficit Hyperactivity Disorder (ADHD), Conduct Disorder, Oppositional Defiant Disorder, Depression, Generalized Anxiety, Social Phobia, Eating Disorders (i.e. DSM disorders), Self-harm, Delinquency, Psychopathy as well as social adaptation problems (e.g. aggression). They also rated interference with functioning in four contexts (family, friends, school, daily life). Reliability analyses indicated good to excellent internal consistency for most scales (alpha = 0.70-0.97) except Psychopathy (alpha = 0.46). The hypothesized structure of the instrument showed acceptable fit according to confirmatory factor analysis (CFA) [Chi-square (4155) = 9776.2, p = 0.000; Chi-square/DF = 2.35; root mean square error of approximation (RMSEA) = 0.031; Comparative Fit Index (CFI) = 0.864], and good convergent and discriminant validity according to multitrait-multimethods analysis. This initial study showed adequate internal validity and reliability of the MIA. Our findings open the way for further studies investigating other validity aspects, which are necessary before recommending the wide use of the MIA in research and clinical settings.

Personal and familial predictors of peer victimization trajectories from primary to secondary school.

Using a sample of 767 children (403 girls, 364 boys), this study aimed to (a) identify groups with distinct trajectories of peer victimization over a 6-year period from primary school through the transition to secondary school, and (b) examine the associated personal (i.e., aggression or internalizing problems) and familial (family status, socioeconomic status, the parent-child relationship) predictors. Peer victimization was assessed via self-reports from Grades 4 through 9 (ages 10 through 15 years), aggression and internalizing problems were assessed in Grade 4 via peer nominations, and the parent-child relationship was assessed in Grade 7 (i.e., right after the transition to secondary school) via parent-reports. Growth Mixture modeling revealed 1 group (62%) who experienced little victimization in primary school and even less in secondary school, another group (31%) who was victimized in primary but not or much less in secondary school, and a third group (7%) who was chronically victimized in both school contexts. Boys were more likely than girls to follow any elevated victimization trajectory. Chronic victimization across primary and secondary school was predicted by nonintact family status and a combination of both internalizing problems and aggression compared with nonvictimized youth. In contrast, transitory victimization during primary but not in secondary school was predicted by aggression, but not internalizing problems. Support as well as conflict in the parent-child relationship also showed significant, albeit distinct associations with the different peer victimization trajectories. (PsycINFO Database Record

The Association Between Peer and own Aggression is Moderated by the BDNF Val-met Polymorphism.

Peer antisocial behavior robustly predicts adolescents' own behavior but not all adolescents are equally vulnerable to their peers' influence and genetic factors may confer vulnerability. This study used data of n = 3081 adolescents from the Avon Longitudinal Study of Parents and Children (ALSPAC) to examine whether BDNF, a polymorphism that affects psychological functioning, moderates the association between affiliation with aggressive peers at age 10 and own aggression at age 15. A significant gene-environment interaction was found, where those who affiliated with aggressive peers in childhood showed increased risk for being aggressive in adolescence if they carried the BDNF met-met variant compared to val-val carriers. Our findings underline the importance of both biological and social factors for adolescent development.

Childhood socioeconomic position and blood pressure dipping in early adulthood: a longitudinal study.

BACKGROUND: The experience of low socioeconomic position in childhood may increase risk for adult cardiovascular disease above and beyond the effects of current socioeconomic position. One limitation of most previous research is that childhood socioeconomic position was assessed retrospectively. METHODS: Measures of ambulatory blood pressure, heart rate, and heart rate variability were obtained from 110 young men (22 years) who were enrolled in a long-term study of child development at age 6. RESULTS: Men who had lower childhood socioeconomic position had smaller decreases in systolic blood pressure (SBP) during sleep independent of current education, daytime SBP, and body mass index (BMI). They also displayed smaller decreases in low-frequency heart rate variability during sleep. Twenty-four-hour SBP was negatively associated with childhood socioeconomic position independent of current education and BMI. CONCLUSIONS: While the mechanisms are unclear, childhood socioeconomic position may influence blood pressure in early adulthood independent of current life circumstances.

Gene-environment processes linking aggression, peer victimization, and the teacher-child relationship.

Aggressive behavior in middle childhood is at least partly explained by genetic factors. Nevertheless, estimations of simple effects ignore possible gene-environment interactions (G × E) or gene-environment correlations (rGE) in the etiology of aggression. The present study aimed to simultaneously test for G × E and rGE processes between aggression, on the one hand, and peer victimization and the teacher-child relationship in school, on the other hand. The sample comprised 124 MZ pairs and 93 DZ pairs assessed in Grade 1 (mean age = 84.7 months). Consistent with rGE, children with a presumed genetic disposition for aggression were at an increased risk of peer victimization, whereas in line with G × E, a positive relationship with the teacher mitigated the genetically mediated expression of aggression.

Early adolescent depressive symptoms: prediction from clique isolation, loneliness, and perceived social acceptance.

This study examined whether clique isolation predicted an increase in depressive symptoms and whether this association was mediated by loneliness and perceived social acceptance in 310 children followed from age 11-14 years. Clique isolation was identified through social network analysis, whereas depressive symptoms, loneliness, and perceived social acceptance were assessed using self ratings. While accounting for initial levels of depressive symptoms, peer rejection, and friendlessness at age 11 years, a high probability of being isolated from cliques from age 11 to 13 years predicted depressive symptoms at age 14 years. The link between clique isolation and depressive symptoms was mediated by loneliness, but not by perceived social acceptance. No sex differences were found in the associations between clique isolation and depressive symptoms. These results suggest that clique isolation is a social risk factor for the escalation of depressive symptoms in early adolescence. Implications for research and prevention are discussed.

Predictive validity and early predictors of peer-victimization trajectories in preschool.

CONTEXT: From the time of school entry, chronic levels of victimization by one's peers predict a multitude of psychiatric and physical health problems. However, developmental trajectories of peer victimization, from the time children first begin to socially interact, are not currently known nor are early familial or child predictors. OBJECTIVES: To describe preschool trajectories of peer victimization, assess continuity of preschool victimization after school entry, and examine early child- and family-level predictors of preschool trajectories of victimization. DESIGN: A longitudinal, large-scale, multiple-informant, population-based study. SETTING: Québec Longitudinal Study of Child Development. PARTICIPANTS: One thousand nine hundred seventy children (51% boys). MAIN OUTCOME MEASURES: Developmental trajectories were described using mothers' reports of peer victimization at 4 times from 3(1/3) to 6(1/6) years of age. In first grade (mean age, 7.2 years), teacher and child reports of peer victimization were collected. Family-level predictors, mostly at age 17 months, included measurements of family adversity (insufficient income [when the infant was aged 5 months], single-parent family, low education, or teenaged mother) and harsh, reactive parenting. Child-level predictors at age 17 months were the mother's ratings of physical aggression, hyperactivity, and emotional problems. RESULTS: Three preschool trajectories of peer victimization were identified (low/increasing, moderate/increasing, and high/chronic). In first grade, children following high/chronic and moderate/increasing preschool trajectories were highest in teacher- and child-rated peer victimization. High levels of harsh, reactive parenting predicted high/chronic peer victimization over and above other child- and family-level variables. Insufficient parent income and child physical aggression predicted the high/chronic and moderate/increasing peer-victimization trajectories. CONCLUSIONS: Early childhood preventive interventions should target parenting skills and child behaviors, particularly within families with insufficient income. Together, these risks confer a heightened likelihood for continued peer victimization as rated by mothers, teachers, and the children themselves.

Life course turning points: the effect of grade retention on physical aggression.

Our objective is to advance the life course analytical framework by demonstrating a model for testing two of its tenets. The first is whether the individual's developmental history conditions the response to a turning point event. The second is whether the influence of a major life event upon an individual's developmental course depends upon the timing of the event. We test both propositions in an analysis of the effect of grade retention on a child's trajectory of physical aggression. Our analysis is based on data from a longitudinal study of 1,037 boysfrom schools in the lowest socioeconomic areas in Montreal, Canada. We find clear evidence that a developmental history of physical aggression conditions the child's response to grade retention. The evidence on whether the timing of retention affects this response is less clear.