Methods of structural equation modelling were used to analyse the correlations between reports of tobacco, alcohol, and cannabis use in a birth cohort of New Zealand children studied to the age of 16. This analysis produced three major conclusions: (a) the correlations between tobacco, alcohol, and cannabis use could be explained by a factor representing the individual's vulnerability to substance use; (b) predictors of vulnerability to substance use were the extent to which the individual affiliated with delinquent or substance using peers, novelty seeking, and parental illicit drug use; (c) in the region of 54% of the correlations between substance use behaviours could be predicted from observed risk factors and 46% was attributable to non-observed sources of vulnerability.

There is limited evidence that siblings of stillborn infants are more vulnerable to psychological problems. This case-controlled study examines the relationship between previous stillbirth and the next child's pattern of attachment and explores factors in the mother which may be associated with and which may explain the pattern of infant attachment. We examined 53 infants next-born after a stillbirth, and 53 control infants of primigravid mothers. Maternal demographic, psychiatric, and attachment data were collected in pregnancy, and self-report measures of depression collected in the first year. Infant attachment patterns to the mothers were assessed when the infants were 12 months old using the Ainsworth Strange Situation Procedure. Infants next-born after stillbirth showed significant increase in disorganisation of attachment to the mother compared with control infants (p < .04). The difference was not accounted for by differences in psychiatric symptoms or demography. It was strongly predicted by maternal unresolved status with respect to loss as measured in the Adult Attachment Interview, and less strongly by maternal experience of elective termination of pregnancy and by the mother having seen her stillborn infant. The study adds weight to previously reported clinical observations, that infants born after stillbirth may be at risk of an increase in psychological and behavioural problems in later childhood. The strong association between disorganisation of infant attachment and maternal state of mind with respect to loss suggests that the mother's state of mind may be causal, and raises interesting questions about the mechanism of intergenerational transmission. Given the existing evidence of later developmental problems, longer-term follow-up of these children would be valuable.

Individuals with Down syndrome suffer from relatively poor verbal short-term memory. Previous explanations of this deficit have been framed in terms of inefficient or absent rehearsal of verbal material in Down syndrome within the phonological loop component of Baddeley and Hitch's (1974) working memory model. Two experiments are presented which test this explanation by looking for the markers of rehearsal in children with Down syndrome and verbal mental age matched controls. Both experiments confirm that individuals with Down syndrome show poorer verbal short-term memory performance than controls. However, they rule out rehearsal as an explanation of these deficits because the evidence suggests that neither individuals with Down syndrome nor matched controls are engaging in spontaneous subvocal rehearsal. Other explanations of poor verbal short-term memory performance in Down syndrome, in terms of impairments both within and outside of the phonological loop system, are discussed. Practical implications for intervention strategies aimed at improving verbal short-term memory skills in Down syndrome are also outlined.

This study on children with a Pervasive Developmental Disorder (PDD; N = 32), children with developmental language disorder (N = 22), and normally developing children (N = 28) sought to answer questions concerning attachment and autistic behaviour. We could replicate the finding that children with a PDD are able to develop secure attachment relationships to their primary caregiver. Children with PDD who had an insecure attachment showed fewer social initiatives and responses than children with PDD who had a secure attachment, even when the insecurely and securely attached PDD children were matched on chronological and mental age. Children with both a PDD and mental retardation were more often classified as disorganised.

Three findings suggested that a disorganised attachment does not merely reflect the presence of “autistic” behaviour: (1) children with PDD did not reveal higher rates of a disorganised attachment than matched comparison children; (2) having a PDD diagnosis and having a disorganised attachment were found to be associated with opposite effects on an ethological measure of level of behavioural organisation; and (3) a disorganised attachment but not a PDD diagnosis was associated with an increase in heart rate during parting with the caregiver and a decrease in heart rate during reunion.

The main aim of this study was to combine two research approaches to hyperactivity: the behaviour genetic approach and the testing of psychological theories of hyperactivity. For a sample of 268 twin pairs aged 7–11 years we obtained ratings on the Conners' scales from both teachers (CTRS-28) and parents (CPRS-48). Forty-six hyperactive twin pairs (pairs in which at least one twin was pervasively hyperactive) and 47 control twin pairs were assessed on a psychological test battery. Confirming findings from previous twin studies, a substantial proportion of the variance in hyperactivity considered as a dimension was due to genetic effects. There was significant evidence of genetic effects also on extreme hyperactivity, although the present group heritability estimates were somewhat lower than those reported in most previous studies. We investigated the possibility that the psychological mechanisms we reported to be associated with hyperactivity (Kuntsi, Oosterlaan, & Stevenson, 2001) share common genetic factors with hyperactive behaviour. The data produced significant evidence of such shared genetic effects only on hyperactivity and the variability of reaction times. Given that the high variability in speed of responding would indicate a state-regulation problem, this is the psychological mechanism that could possibly be the “link” between genetic effects and hyperactive behaviour.

Advances in quantitative psychiatric genetics as a whole are reviewed with respect to conceptual and methodological issues in relation to statistical model fitting, new genetic designs, twin and adoptee studies, definition of the phenotype, pervasiveness of genetic influences, pervasiveness of environmental influences, shared and nonshared environmental effects, and nature–nurture interplay. Advances in molecular genetics are discussed in relation to the shifts in research strategies to investigate multifactorial disorders (affected relative linkage designs, association strategies, and quantitative trait loci studies); new techniques and identified genetic mechanisms (expansion of trinucleotide repeats, genomic imprinting, mitochondrial DNA, fluorescent in-situ hybridisation, behavioural phenotypes, and animal models); and the successful localisation of genes.

Data from two twin studies are examined to assess genetic and environmental influences on literacy, and the etiological relationship between language and literacy. Study 1 used children from 86 families previously recruited for a study of the genetics of specific language impairment (see Bishop, North, & Donlan, 1995), who completed tests of single-word reading and spelling. Literacy problems in this sample were common, were strongly heritable, and showed a close genetic relationship with poor nonword repetition. Study 2 included two subsets of children: 37 twin pairs who had taken part in study 1, 3 to 4 years earlier, and 100 twin pairs recruited from the general population by Bishop et al. (1999). All children were given a standardised test of nonword reading. There was no genetic influence on nonword reading ability, either across the normal range, or at the lower extreme, though there were significant associations with some social variables. However, bivariate DeFries–Fulker analysis suggested that in this study, as in study 1, there was shared genetic variance between poor nonword repetition and literacy deficits. It is concluded that poor nonword repetition, which is known to be highly heritable, puts the child at risk for literacy problems. However, in a general population sample, such as that included in study 2, poor nonword repetition is a relatively rare correlate of literacy problems, which are more likely to have an environmental origin. Thus the different pattern of results in the two studies can be explained if one assumes that genetic influences are substantial only when literacy problems are severe and/or accompanied by oral language difficulties.

Fifty years ago the Children Act (1948) created the modern child care service in England and Wales. Then, as now, the preferred form of state-provided care for children was foster, rather than residential, care. However, the nature of foster family care has changed considerably over the past 50 years and, in some respects, so have the children fostered. Then the predominant form of foster care was long-term care, in keeping with the prevailing ideology of “rescuing” children from intolerable home conditions. Now, by contrast, foster care is a much more diverse service, and the commonest form is short-term care, which is generally understood as care intended to last less than roughly 3 months. This is in keeping with a strong ideology in both the U.S.A. and the U.K. that foster care is not parenting, and that almost all children are best off with their biological parents.

Inferior auditory temporal processing has been postulated as causally linked to phonological processing deficits in disabled readers with concomitant oral language delay (LDRDs), and absent in specifically disabled readers with normal oral language (SRDs). This investigation compared SRDs, LDRDs and normal readers aged 7–10 years on measures of auditory temporal processing (temporal order judgement) and phonological decoding (nonword reading). LDRDs exhibited deficits in temporal order judgement compared with normal readers, from whom SRDs did not differ significantly. These findings suggest that auditory temporal processing and oral language are related; however, very large within-group variability in the auditory temporal processing data further suggests that this relationship prevails in only a proportion of disabled readers with concomitant oral language weakness. In nonword reading, LDRDs performed worst of all, but SRDs also exhibited significant deficits compared with normal readers. Taken together, our results preclude the conceptualisation of temporal processing deficits as the unitary cause of phonological and language deficits in disabled readers.

Although a role for family and parent factors in the development of behavioral problems in childhood is often acknowledged, the roles of specific parental characteristics in relation to specific child actions need further elucidation. We studied parental “Big Five” personality traits and psychiatric diagnoses in relation to their children's antisocial diagnoses and naturalistically observed antisocial behaviors, in boys with and without the diagnosis of Attention-Deficit Hyperactivity Disorder (ADHD). First, regardless of comorbid antisocial diagnosis, boys with ADHD, more often than comparison boys, had mothers with a major depressive episode and/or marked anxiety symptoms in the past year, and fathers with a childhood history of ADHD. Second, compared to the nondiagnosed group, boys with comorbid ADHD+Oppositional Defiant or Conduct Disorder (ODD/CD) had fathers with lower Agreeableness, higher Neuroticism, and more likelihood of having Generalized Anxiety Disorder. Third, regarding linkages between parental characteristics and child externalizing behaviors, higher rates of child overt antisocial behaviors observed in a naturalistic summer program were associated primarily with maternal characteristics, including higher Neuroticism, lower Conscientiousness, presence of Major Depression, and absence of Generalized Anxiety Disorder. The association of maternal Neuroticism with child aggression was larger in the ADHD than in the comparison group. In contrast, higher rates of observed child covert antisocial behaviors were associated solely with paternal characteristics, including history of substance abuse and higher Openness. Results provide external validation in parent data for a distinction between overt and covert antisocial behaviors and support inclusion of parent personality traits in family studies. The interaction of maternal Neuroticism and child ADHD in predicting child aggression is interpreted in regard to a conceptualization of child by parent “fit.”

Abbreviations: ADHD: Attention-Deficit Hyperactivity Disorder; CBCL: Child Behavior Checklist; CD: Conduct Disorder; DBD: Disruptive Behaviors Checklist; DIS-3-R: Diagnostic Interview Schedule for DSM-III-R; MMPI: Minnesota Multiphasic Personality Inventory; NEO-FFI: Neuroticism, Extraversion, Openness Five Factor Inventory; ODD: Oppositional Defiant Disorder; WURS: Wender Utah Rating Scale.

Previous research has shown that children receiving substitute parental care tend to have high rates of emotional/behavioural disturbance, but uncertainty remains on the extent to which this derives from genetic risk, adverse experiences before receiving substitute care, or from risks associated with substitute care experiences. In order to examine the effects of institutional rearing (as a specific form of substitute care), two groups of primary school children reared in substitute care from before the age of 12 months were compared: 19 children in residential group (institutional) care and 19 in continuous stable foster family care (matched for age and gender). The two groups were similar in coming from biological families with high rates of psychopathology and social malfunctioning, but differed with respect to pattern of rearing. Both groups were compared with classroom controls, using teacher questionnaires, systematic classroom observations, and standardised cognitive testing. Parental questionnaires were also obtained for the two substitute care groups. As found previously, the combined substitute care groups differed from controls in showing a high level of hyperactivity/inattention. The observational measures showed a similar effect, indicating that the elevated rate was not attributable to rater bias. The teacher questionnaire and observational measures showed, however, that the increased level of hyperactivity/inattention was substantially higher in the institutional group than the foster family group. Parental questionnaire ratings showed the same contrast between the groups, except that the main difference was on unsociability and emotional disturbance rather than hyperactivity/inattention. It is concluded that, against a background of genetic and early environmental risk, institutional rearing predisposes to a pattern of hyperactivity/inattention.

A recent finding that individuals with autism are not susceptible to illusions has been explained by Happé (1996) as a sign of “weak central coherence” at lower levels of processing. We investigated the phenomenon with a more sophisticated measure. In Experiment 1, individuals with autism, Asperger's syndrome, moderate learning difficulties, and typical development adjusted certain comparison lines and circles to make them appear to be the same size in four visual illusions. With a minor exception, the participants with autism and Asperger's syndrome evinced a systematic bias in their judgements in the illusion condition. The extent of this was no different from control participants. In a second experiment, a similar finding was obtained in a task where participants made verbal judgements about the stimuli. The results suggest that lower-level coherence in visual processing in autism is intact.

This study examined the relationship between the development of theory of mind and the development of the belief terms think, know, and guess. Children with autism and Asperger syndrome, matched to children with specific language impairment and normal development, completed false belief, belief term comprehension, and belief term expression tasks. The autistic group's performance on the false belief, belief term comprehension, and belief term expression tasks was significantly poorer than that of the Asperger, language impaired, and normal groups. Across groups an association was found between false belief and belief term performance. Results support a growing body of literature demonstrating links between the development of theory of mind and communicative competence.

This study examined the language, achievement, and cognitive characteristics of 380 children, aged 7 to 14 years, consecutively referred to child psychiatric services. Among those children referred solely for psychiatric problems, 40% had a language impairment that had never been suspected. Children with previously identified and unsuspected language impairments were similar with respect to receptive and expressive language and on measures of cognitive processing. Although both groups of children with language impairments exhibited poorer academic achievement than children with normal language, children with previously identified language impairments had the lowest achievement. The milder achievement problems of children with unsuspected language impairment may explain why their problems had not been suspected. Both the clinical and theoretical implications of the findings are discussed. Heightened awareness concerning the high frequency of language impairment and other cognitive processing problems in children referred for psychiatric assessment and treatment should lead to more systematic examination of language functioning and evaluation of the impact of language and communication functioning on therapeutic outcomes.

This study was designed to examine the developmental and cognitive correlates of theory of mind (ToM) and emotion recognition ability in children with autism (N=20), with pervasive developmental disorder-not otherwise specified (PDD-NOS) (N=20), and in psychiatric control children (N=20). The diagnostic groups were person-to-person matched on age and verbal IQ. The age of the children was between 8 and 18 years; their Full Scale IQ was at least 65. The test battery included tasks for the matching and the context recognition of emotional expressions, and a set of first- and second-order ToM tasks. The relationships between composite domain scores and the subjects' age, Verbal IQ, Performance IQ, verbal memory, visual memory, and gender were examined in bivariate and multivariate analyses. Further, the subjects who reliably and consistently passed the tasks of a domain and those who could not were compared on developmental and cognitive characteristics. Overall, the results of the various analyses converged and indicated that verbal memory, Performance IQ, age and gender were the best predictors of social cognitive ability.

One commonly cited feature of Williams syndrome is a characteristic dissociation between relatively spared language skills and severely impaired nonverbal abilities. However, the actual evidence for a dissociation between verbal and nonverbal abilities in Williams syndrome is equivocal. In two separate studies we examined these abilities in 16 individuals showing the Williams syndrome phenotype. When considered as a whole, the group did have significantly superior verbal abilities, but this difference was caused by a large discrepancy in abilities in only a small number of individuals. In both studies there was a clear, linear relation between individuals' verbal ability, and the magnitude of their verbal–nonverbal discrepancy. We suggest that these results are best explained in terms of verbal ability developing at a faster rate than nonverbal ability in this disorder. We discuss how this model of differential rates of development has the potential to reconcile the apparently inconsistent findings in this area.

The “mindblindness” theory of core cognitive impairment in autism and at least one of the executive theories of the core cognitive deficit both predict that children with autism should find it difficult to report what their intention was when it diverged from an outcome. The former predicts this because it takes intention reporting to require a “theory of mind” and the latter predicts it because the theory posits an impairment in the monitoring of goal-directed actions. The latter also predicts impairments in the ability to monitor basic actions. Our three studies failed to support either of these views. Experiment 1 demonstrated intact abilities in the monitoring of basic actions (detecting which stimulus of a number of stimuli one is controlling). Experiment 2 demonstrated intact abilities in reporting an intention, both for self and for another agent, when the outcome was unintended but desired. In Experiment 3, using the novel “transparent intentions task”, we found (with a minor qualification) intact ability in reporting on nonballistic intended actions when the result that the action achieved was unexpected. The implications of these results for views of the relation between theory of mind and executive difficulties in autism are discussed.

By investigating egg donation families, donor insemination families, adoptive families, and families created by in vitro fertilization, the aim of the present study was to examine parents' emotional well-being, the quality of parenting, and childrens' socioemotional development in families with a child who is genetically unrelated to the mother or the father. The differences that were found to exist between families according to the presence or absence of genetic ties between parents and their children reflected greater psychological well-being among mothers and fathers in families where there was no genetic link between the mother and the child. The families did not differ with respect to the quality of parenting or the psychological adjustment of the child.

It is well established that people with autism have impaired face processing, but much less is known about voice processing in autism. Four experiments were therefore carried out to assess (1) familiar voice-face and sound-object matching; (2) familiar voice recognition; (3) unfamiliar voice discrimination; and (4) vocal affect naming and vocal-facial affect matching. In Experiments 1 and 2 language-matched children with specific language impairment (SLI) were the controls. In Experiments 3 and 4 language-matched children with SLI and young mainstream children were the controls. The results were unexpected: the children with autism were not impaired relative to controls on Experiments 1, 2 and 3, and were superior to the children with SLI on both parts of Experiment 4, although impaired on affect matching relative to the mainstream children. These results are interpreted in terms of an unexpected impairment of voice processing in the children with SLI associated partly, but not wholly, with an impairment of cross-modal processing. Performance on the experimental tasks was not associated with verbal or nonverbal ability in either of the clinical groups. The implications of these findings for understanding autism and SLI are discussed.

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.