Show me the child at seven II: Childhood intelligence and later outcomes in adolescence and young adulthood

BACKGROUND: There has been ongoing interest in the role of intelligence in longer-term educational and occupational achievement and social adjustment. The aims of this study were to examine the extent to which IQ in middle childhood (8-9 years) was prognostic of future outcomes when due allowance was made for confounding personal and social factors. METHODS: Data were gathered on (WISC-R) IQ at ages 8-9 years and a range of educational and social adjustment measures over the course of the Christchurch Health and Development Study, a 25-year longitudinal study of a birth cohort of 1,265 New Zealand children. RESULTS: IQ assessed at ages 8-9 years was related to a range of outcomes: later crime (offending, arrest/conviction); substance use disorders (nicotine dependence, illicit drug dependence); mental health (anxiety, suicidality); sexual adjustment (number of sexual partners, pregnancy); educational achievement (school leaving qualifications, tertiary qualifications); and occupational outcomes (unemployment, income). However, intelligence was largely unrelated to many of these outcomes: crime, mental health, sexual behaviours, and illicit substance dependence after statistical adjustment for early behaviour problems and family background. Strong relationships remained between childhood intelligence and later educational and occupational outcomes. CONCLUSIONS: Much of the association between early intelligence and later social adjustment is mediated by childhood conduct problems and family social circumstances. However, strong relationships exist between early intelligence and later academic achievement and income independently of these factors.     

Educational, psychosocial, and sexual outcomes of girls with conduct problems in early adolescence

This paper examines the extent to which conduct problems at age 13 are associated with a range of educational, psychosocial, and sexual outcomes at age 18 in a birth cohort of 488 young women. Significant associations were found between early adolescent conduct problems and later risks of educational failure, juvenile crime, substance abuse, mental health problems, and adverse sexual outcomes by late adolescence. These elevated risks were explained, in part, by social, family, and personal disadvantages associated with adjustment at age 13. In addition, there was evidence of a causal chain process in which early adolescent conduct problems were associated with a series of adolescent risk-taking behaviours, including delinquent peer affiliations, early-onset sexual behaviour, substance use, and school problems that were, in turn, associated with increased risks of later adverse outcomes.     

Early Conduct Problems and Later Life Opportunities

Associations between the extent of conduct problems at age 8 years and later life opportunity outcomes at age 18 years were examined in a birth cohort of New Zealand children studied prospectively to age 18 years. Conduct problems at age 8 were assessed using a combination of parent and teacher reports of conduct disordered and oppositional behaviours. Two measures of life opportunities were assessed at age 18: (a) whether the young person had left school by age 18 without educational qualifications; (b) whether the young person had experienced a period of unemployment of 3 months or longer following school leaving. The analysis suggested the following conclusions: (1) There were clear and significant ( p < .0001) tendencies for increasing levels of conduct problems at age 8 to be associated with increasing risks of leaving school without qualifications and of unemployment by age 18. (2) A substantial component of these associations was explained by a series of confounding social, family, and individual factors (notably child intelligence, early attentional problems, and family sociodemographic disadvantage) that were associated with both early conduct problems and later life opportunities. (3) Further analysis suggested that linkages between early conduct problems and later educational underattainment and unemployment (after adjustment for confounders) were mediated by a series of adolescent behavioural processes including patterns of peer affiliations, substance use, truancy, and problems with school authority.     

Effects on later adjustment of living in a stepfamily during childhood and adolescence

This paper examines the effects of living in a stepfamily during childhood and adolescence on a range of psychosocial outcomes at age 18 years. Data collected during an 18-year longitudinal study were used to examine a sample of 907 children with respect to: exposure to living in a stepfamily during the period from age 6 to 16 years; measures of psychosocial outcomes including mental health, antisocial behaviour, substance use, restricted life opportunities, and sexual risk-taking at age 18 years; and measures of prospectively collected confounding factors. The analyses revealed that children exposed to living in a stepfamily for the first time between ages 6-16 years had elevated risks of a range of psychosocial outcomes at 18 years. These included elevated risks of: (1) juvenile offending; (2) nicotine dependence; (3) abuse or dependence on illicit substances; (4) leaving school without qualifications; (5) early onset of sexual activity; and (6) multiple sexual partners. However, these risks were reduced substantially when psychosocial outcomes were adjusted for the confounding effects of antecedent factors such as: family socioeconomic characteristics: family history of instability, adversity, and conflict; mother's age, religiosity, and smoking; child gender; and preexisting child conduct and attentional problems. After adjustment, the odds ratios between exposure to a stepfamily and adolescent outcomes were nonsignificant. Additional analysis revealed that there were no significant differences in outcomes for boys and girls exposed to stepfamilies. It was concluded that although young people exposed to living in a stepfamily had increased risks of poor psychosocial outcomes, much of this association appeared to be spurious, and arose from confounding social, contextual, and individual factors that were present prior to the formation of the stepfamily.     

Early Reading Difficulties and Later Conduct Problems

The relationships between early reading difficulties and later conduct problems were examined in a birth cohort of New Zealand children studied from the point of school entry to the age of 16. Children with early reading difficulties had increased rates of conduct problems up to the age of 16 years. These associations depended on context, being more evident for boys and tending to reduce with increasing age. However, the associations between early reading difficulties and later conduct problems were explained by the fact that children with early reading difficulties tended to be characterised by a number of disadvantageous features (and notably early-onset conduct problems) that were present before the onset of reading difficulties. When the associations between reading difficulties and conduct problems were adjusted for confounding factors there were no statistically significant associations between reading difficulties and conduct problems. These results were found to hold for various age and gender subgroups of the sample, for measures of reading difficulties defined in different ways, and for a wide range of outcome variables. It is concluded that, when due allowance is made for potentially confounding factors (and notably early conduct problems) and for factors correlated with these problems, it is unlikely that reading difficulties in early childhood are related to later conduct problems.     

Childhood peer relationship problems and later risks of educational under-achievement and unemployment

This paper examines relations between the extent of children's peer relationship problems at age 9 and their later risks of educational under-achievement and unemployment by the age of 18 years. Results showed that children with high rates of early peer relationship problems were at increased risk of under-achievement and unemployment when compared with children with low rates of early peer relationship problems. These elevated educational and occupational risks were explained by two processes. First, associations between early peer difficulties and later disadvantage were in part noncausal, and arose because of the personal characteristics (IQ and attentional problems) and social backgrounds (socioeconomic adversity, exposure to parental change, and punitive parent-child interaction) of children with early peer problems. Second, problematic peer relations during childhood appeared to place young people at increased risk of a range of adolescent interpersonal and school-related difficulties, including weaker peer attachments, interpersonal problems with teachers, school truancy, suspension, and early school leaving. In turn, these experiences and behaviours served to reduce the educational and employment opportunities of children with early peer problems. Results highlight the importance of childhood peer relationships for academic and occupational success.     

The long-term significance of teacher-rated hyperactivity and reading ability in childhood: findings from two longitudinal studies

BACKGROUND: The aims of this study were twofold: first, to examine behavioural and academic outcomes of children with hyperactivity, using data from two longitudinal studies; and second, to examine comparable psychosocial outcomes for children with early reading difficulties. METHODS: Measures of teacher-rated persistent hyperactivity, and reading ability obtained during early primary school were available for children from the Australian Temperament Project and the Dunedin Multidisciplinary Health and Development Study. Both samples were followed up to assess behavioural and academic outcomes during the adolescent and early adult years. Family background, antisocial behaviour and literacy were controlled in the first set of analyses to examine the influence of early hyperactivity. RESULTS: There were strong linear relationships between early hyperactivity and later adverse outcomes. Adjustment for other childhood variables suggested that early hyperactivity was associated with continuing school difficulties, problems with attention and poor reading in adolescence. Early reading difficulties, after controlling for early hyperactivity, predicted continuing reading problems in high school and leaving school with no qualifications. CONCLUSIONS: The findings suggest that there are dual pathways from early inattentive behaviours to later inattention and reading problems, and from early reading difficulties to substantial impairments in later academic outcomes.     

Maternal age and educational and psychosocial outcomes in early adulthood

The relationships between maternal age (at birth) and educational and psychosocial outcomes at age 18 were examined in a birth cohort of 1025 New Zealand children. This analysis indicated the presence of consistent tendencies for increasing maternal age to be associated with declining risks of educational underachievement, juvenile crime, substance misuse, and mental health problems. Children with teenage mothers had risks of later adverse outcomes that were 1.5 to 8.9 times higher than the risks for offspring of mothers aged over 30. Subsequent analyses revealed that the associations between maternal age and later educational and psychosocial outcomes were largely, but not wholly, explained by associations between maternal age and the child-rearing practices and home environments experienced by children. In general, increasing maternal age tended to be associated with more nurturant, supportive, and stable home environments. In turn, these linkages between maternal and childhood environment explained most of the association between maternal age and later outcomes. The theoretical and applied implications of these results are considered.     

Early motherhood and subsequent life outcomes

Background:  Early motherhood has been linked with a number of adverse outcomes, including mental health difficulties and barriers to completing educational qualifications and workforce participation. The present study examined the extent to which these linkages could be explained by the influence of social, family, and background factors that were associated with early motherhood.
Methods:  Data were gathered as part of the Christchurch Health and Development Study, a 25-year longitudinal study of a birth cohort of New Zealand children. Information was obtained on: (a) the history of pregnancy and parenthood for female participants over the period 15–21 years; (b) measures of DSM-IV mental disorders and suicidal behaviour over the interval 21–25 years; (c) measures of educational achievement over the interval 21–25 years; (d) measures of welfare dependence, workforce participation, and income over the interval 21–25 years; and (e) childhood, family and related confounding factors.
Results:  Early motherhood was associated with higher levels of mental health disorders, lower levels of educational achievement, higher levels of welfare dependence, lower levels of workforce participation, and lower income. Control for confounding factors reduced the associations between early motherhood and later mental health disorders to statistical non-significance. However, the associations between early motherhood and later educational achievement and economic circumstances persisted after control for potentially confounding factors.
Conclusions:  The findings suggest that early motherhood puts young women at risk for educational underachievement and poorer economic circumstances. The linkages between early motherhood and later mental health difficulties can largely be accounted for by childhood, family, and related circumstances that occurred prior to parenthood.     

Show me the child at seven: the consequences of conduct problems in childhood for psychosocial functioning in adulthood

BACKGROUND: This paper seeks to extend research into the adult sequelae of childhood conduct problems by investigating the associations between conduct problems in middle childhood and psychosocial outcomes in adulthood. METHOD: Data were gathered during the course of a 25-year longitudinal study of a birth cohort of New Zealand young people. Information was collected on: a) parent and teacher reports of child conduct problems at ages 7, 8 and 9 years; b) measures of crime, substance use, mental health, sexual/partner relationships, education/employment; c) confounding factors, including childhood, family and educational characteristics. RESULTS: There were statistically significant associations between childhood conduct problems from 7-9 years and risks of adverse outcomes across all domains of functioning. After control for confounding factors the associations between conduct problems and education/employment outcomes became statistically non-significant. Associations persisted for other outcomes (crime, substance dependence, mental health and sexual/partner relationships). Children in the most disturbed 5% of the cohort had rates of these outcomes that were between 1.5 and 19 times higher than rates for the least disturbed 50% of the cohort. The associations between conduct problems and adult outcomes were similar for males and females. CONCLUSIONS: Childhood conduct problems were associated with a wide range of adverse psychosocial outcomes (crime, substance use, mental health, sexual/partner relationships) even after control for confounding factors. The results reinforce the need for greater investment into interventions to address these problems.     

Reading Problems and Antisocial Behaviour: Developmental Trends in Comorbidity

Samples of poor and normal readers were followed through adolescence and into early adulthood to assess continuities in the comorbidity between reading difficulties and disruptive behaviour problems. Reading-disabled boys showed high rates of inattentive-ness in middle childhood, but no excess of teacher-rated behaviour problems at age 14 and no elevated rates of aggression, antisocial personality disorder or officially recorded offending in early adulthood. Increased risks of juvenile offending among specifically retarded-reading boys seemed associated with poor school attendance, rather than reading difficulties per se , Reading problems were associated with some increases in disruptive behaviour in their teens in girls.     

Deviant partner involvement and offending risk in early adulthood

BACKGROUND: This paper examines the effects of deviant and non-deviant partner involvement at age 21 on patterns of continuity and change in offending between the ages of 18 and 21 years in a birth cohort of 983 young men and women. RESULTS: Results showed that those involved with a non-deviant partner had lower rates of offending at age 21 than those with no partner, whilst those without a partner had lower rates of offending at age 21 than those involved with a deviant partner. Associations between deviant/non-deviant partner involvement and offending risk best fitted a main effects model in which both offending at age 18 and young people's partnership choices at age 21 made independent and additive contributions to the prediction of offending at age 21. There was no interaction between offending at age 18 and partner choice at age 21 in determining offending risk in early adulthood. In addition, the effects of deviant/non-deviant partner involvement on patterns of offending were the same for men and women, and were found to persist even after extensive control for the confounding effects of a wide range of selection factors measured during childhood and adolescence. CONCLUSION: These results highlight the importance of partnership choices during early adulthood in determining young people's risk of offending as adults.     

Early Dentine Lead Levels and Educational Outcomes at 18 Years

The associations between early dentine lead levels measured at the age of 6–8 years and educational outcomes measured at IS years were examined in a birth cohort of 1265 New Zealand children. Analyses showed significant (p > .005) dose/response relationships between early dentine lead levels and later outcomes: at age 18 children with early elevated lead levels had poorer reading abilities, had more often left school early, had more often left school without qualifications, and had lower levels of success in school examinations. These associations persisted after Statistical control for a range of social and familial confounding factors. A number of potential threats to the validity of the findings are examined, including sample selection bias, statistical undercontrol of covariates, and errors of measurement. It is concluded that the findings are consistent with the view that early mildly elevated lead levels have modest but delectable effects on individual achievement, with these effects extending to late adolescence.     

Abortion in young women and subsequent mental health

BACKGROUND: The extent to which abortion has harmful consequences for mental health remains controversial. We aimed to examine the linkages between having an abortion and mental health outcomes over the interval from age 15-25 years. METHODS: Data were gathered as part of the Christchurch Health and Development Study, a 25-year longitudinal study of a birth cohort of New Zealand children. Information was obtained on: a) the history of pregnancy/abortion for female participants over the interval from 15-25 years; b) measures of DSM-IV mental disorders and suicidal behaviour over the intervals 15-18, 18-21 and 21-25 years; and c) childhood, family and related confounding factors. RESULTS: Forty-one percent of women had become pregnant on at least one occasion prior to age 25, with 14.6% having an abortion. Those having an abortion had elevated rates of subsequent mental health problems including depression, anxiety, suicidal behaviours and substance use disorders. This association persisted after adjustment for confounding factors. CONCLUSIONS: The findings suggest that abortion in young women may be associated with increased risks of mental health problems.     

Prospective Childhood Predictors of Deviant Peer Affiliations in Adolescence

Data gathered over the course of a longitudinal study of a birth cohort of over 900 New Zealand children were used to examine factors associated with the formation of affiliations with delinquent or substance using peers in adolescence (15 years). The findings of this study include: (1) Adolescent peer affiliations were associated with a wide range of prospectively measured social, family, parental, and individual factors. This analysis indicated that those children most at risk of forming deviant peer affiliations were those from socially disadvantaged backgrounds, dysfunctional families, who showed early onset conduct problems and other difficulties. (2) Regression analysis suggested that specific factors that were associated with increased risks of later deviant peer affiliations included family socioeconomic status, parental conflict, mother/child interaction, childhood sexual abuse, parental alcoholism, parental criminal offending, parental illicit drug use, parental smoking, early conduct problems, early anxiety/withdrawal, and early smoking experimentation. It is concluded that peer affiliations in adolescence are shaped by a complex social, family, and individual process that includes social stratification, family functioning, and individual behavioural predispositions.     

Attention across modalities as a longitudinal predictor of early outcomes: the case of fragile X syndrome

Background: Fragile X syndrome (FXS) is an early diagnosed monogenic disorder, associated with a striking pattern of cognitive/attentional difficulties and a high risk of poor behavioural outcomes. FXS therefore represents an ideal model disorder to study prospectively the impact of early attention deficits on behaviour. Methods: Thirty‐seven boys with FXS aged 4–10 years and 74 typically developing (TD) boys took part. Study 1 was designed to assess visual and auditory attention at two time‐points, 1 year apart. Study 2 investigated attention to multimodal information. Both tested attention markers as longitudinal predictors of risk for poor behaviour in FXS. Results: Children with FXS attended less well than mental‐age matched TD boys and experienced greater difficulties with auditory compared to visual stimuli. In addition, unlike TD children, they did not benefit from multimodal information. Attention markers were significant predictors of later behavioural difficulties in boys with FXS. Conclusions: Findings demonstrate, for the first time, greater difficulties with auditory attention and atypical processing of multimodal information, in addition to pervasive global attentional difficulties in boys with FXS. Attention predicted outcomes longitudinally, underscoring the need to dissect what drives differing developmental trajectories for individual children within a seemingly homogeneous group.     

Health needs of Australian Indigenous young people entering detention

Aim: To determine whether there are different health needs associated with differences between Indigenous and non‐Indigenous youth in detention in Brisbane, Queensland, Australia. Methods: All records of young people (aged 10 to 21 years) taken into detention in Brisbane Queensland over the period 1 July 2001 to 30 June 2009 were reviewed, and data were extracted documenting the mental health and related behaviours of those referred to the Mental Health, Alcohol, Tobacco and Other Drugs Service. International Statistical Classification of Diseases and Related Health Problems – Tenth Revision (ICD‐10) criteria were applied to a clinical interview. ICD‐10 diagnostic outcomes and reason for referral are presented by Indigenous status and age. Results: Young male (under 14 years of age) Indigenous respondents are substantially over‐represented in youth in detention. Indigenous youth in detention are disproportionately referred and diagnosed with a substance use problem. Referral and diagnosis of substance use problems was not as commonly found for non‐Indigenous youth. Conclusions: Young Indigenous persons are substantially over‐represented in those taken into detention in Queensland. This study shows significant differences in relation to mental health and substance use assessment outcomes for Indigenous and non‐Indigenous young people in youth detention in Queensland. Further research focusing on service delivery for Indigenous young people should focus on their specific needs.     

Early solid food diet and eczema in childhood: a 10-year longitudinal study

The relationship between early solid feeding in the first four months and risks of eczema in childhood was examined in a birth cohort of 1265 children studied to the age of 10 years. The major findings of this analysis were: 1) children exposed to a diverse solid food diet during their first four months had risks of eczema in early childhood which were about 1.6 times those of children who were not introduced to solid food by age four months. These associations persisted when a range of confounding factors (including family history of atopic disease, infant milk diet (breast/bottle) and family social background factors) were taken into account. 2) Similar associations between early infant diet and risks of chronic and recurrent eczema up to the age of ten years were also found. It was estimated that after adjustment for confounding factors, children exposed to an early diverse solid food diet had risks of eczema which were over 2.5 times those of children not introduced to solid feeding. These results are generally consistent with the hypothesis that early exposure to a diverse solid food diet may increase risks of eczema in children who are susceptible to this condition.     

Childhood bullies and victims and their risk of criminality in late adolescence: the Finnish From a Boy to a Man study

OBJECTIVE: To study correlations of childhood bullying and victimization with juvenile criminality. DESIGN: Longitudinal birth cohort study from age 8 years to ages 16 to 20 years. SETTING: Population-based study from Finland. PARTICIPANTS: The sample comprised 2551 boys (86.6% of the original birth cohort) with complete information about bullying and victimization from parents, teachers, and children at age 8 years. MAIN OUTCOME MEASURE: Information about criminal offenses from the National Police Register at ages 16 to 20 years. RESULTS: Frequent bullies and those who frequently both bullied and were bullied (8.8% of the sample) were responsible for 33.0% of all juvenile crimes during the 4-year study period. Frequent bully-only status predicted both occasional and repeated offending, whereas bully-victim status predicted repeated offending. Bullying predicted most types of crime (violence, property, drunk driving, and traffic offenses) when controlled with parental education level. However, frequent bullies or victims without a high level of psychiatric symptoms were not at an elevated risk for later criminality. CONCLUSIONS: Boys who frequently bully are at risk for later criminality when this condition is accompanied by a high level of psychiatric symptoms. Frequent bullies should be actively screened for psychiatric problems.     

Early anxious/withdrawn behaviours predict later internalising disorders

BACKGROUND: The aim of the study was to examine the association between anxious/withdrawn behaviours at age 8 and the development of internalising disorders in adolescence and young adulthood (ages 16-21). METHODS: Data were gathered over the course of a 21-year longitudinal study of a birth cohort of over 1,000 New-Zealand-born young people. Over the course of the study, data were gathered on: (a) anxious/withdrawn behaviour at age 8; (b) anxiety disorders and major depression at ages 16-18 and 18-21; (c) a range of potential confounding factors, including measures of adversity and family factors during childhood. RESULTS: Increasing anxious/withdrawn behaviour at age 8 was associated with increasing risks of social phobia; specific phobia; panic/agoraphobia; and major depression during adolescence and young adulthood. These associations persisted after adjustment for a series of confounding social, childhood, and family factors. CONCLUSIONS: Anxious/withdrawn behaviour in childhood is associated with elevated rates of anxiety disorders and major depression during adolescence and young adulthood. These data are consistent with, and extend, previous clinical and epidemiologic findings, by showing consistent linkages between childhood anxious/withdrawn behaviours at age 8 and increased risk for anxiety disorders and depression at ages 16-18 and 18-21 among young persons in the community. These results may point to the need to provide support and possibly intervention to children showing early anxious or withdrawn behaviours.