Many children suffer an injury to the head at some time, but relatively few of these cause major problems. However, in a few cases the sequelae can be far reaching. This review considers how to evaluate the significance of a head injury. Factors to consider are (1) injury variables: cause, severity and type of injury; (2) child variables: premorbid functioning, age, and developmental level of the child both at injury and at assessment; and (3) the cognitive, behavioural, and emotional problems that may arise. Parental beliefs and knowledge about the injury as well as the overall effect of an injury on the family as a whole are also considered.

To examine the possibility that there is an early sensitive period for the effects of malnutrition on cognitive development, three groups of children (N = 197) were recruited from a birth cohort with known growth characteristics in south-west Ethiopia (N = 1563). All had initial weights [ges ]2500g. Early growth falterers dropped in weight below the third centile (z<−1·88) of the NCHS/WHO reference population in the first 4 months. Late growth falterers were children not in the first group whose weights were below the third centile at 10 and 12 months. Controls were a stratified random sample with weights above the third centile throughout the first year. All children were tested blind at 2 years using the Bayley Scales of Infant Development, adapted for use in Ethiopia. Mean (SD) scores on the psychomotor scale were 10·2 (3·7) in the controls, 6·6(4·2) in the early growth falterers, and 8·5(4·3) in the late growth falterers. For the mental scale they were 28·9(5·8), 22·6(6·2), and 26·6(6·1) respectively. Both overall differences were statistically significant at p<·001, and planned comparisons between the control and the combined growth faltering groups, and between the early and later growth faltering groups, showed that each difference was statistically significant for both scales. However, early weight faltering was associated with weight at the time of testing (r = .33), which was associated with scores both on the psychomotor (r = .53) and the mental scale (r = .49). After taking weight at the time of testing into account there was no additional effect attributable to the timing of growth faltering. In this population, therefore, early malnutrition does not have specific adverse effect beyond the contribution that it makes to enduring malnutrition over the first 2 years.

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.

This study tested the predictions of three different theories of hyperactivity: response inhibition deficit, working memory impairment, and delay aversion. A sample of 51 pervasively hyperactive children and 119 control children, identified by screening a general population sample of 1316 twin pairs, were assessed on tests relating to each of these theories. The hyperactive group performed worse than the control group on the delay aversion measure and some of the working memory tasks. Controlling for IQ removed the significant group differences on the working memory measures, however. There were no significant group differences on the inhibition variables derived from the stop task. However, there was evidence of a pattern of responding on the stop task that was strongly characteristic of hyperactivity: hyperactive children were variable in their speed, generally slow and inaccurate in responding. This pattern of responses may indicate a nonoptimal effort/activation state. Hyperactive girls were indistinguishable from hyperactive boys in their performance on the tasks.

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.

We report several studies developing a parent-rated measure of emotional distress for children in Singapore, with the key objectives being to derive a very brief valid measure of global distress. The refined item set comprised behaviourally expressed broad manifestations of emotional distress. Three developmental studies were undertaken, with the first two involving parental ratings on the measure for validation against clinician-rated distress levels, while also testing two rating options for the measure. We established clear comparative advantages to the rating anchors used in the Revised Rutter Scales. High inter-rater agreement was established across parental ratings, with the latter finding supporting objectives for the measure. Paternal scores correlated more strongly than maternal scores with clinician-generated distress scores. Additional properties of the measure were tested in a large community sample of nearly 2000 Singapore schoolchildren in their last 2 years of primary school, allowing prevalence estimates and mean scores to be derived for each item. Here, girls and boys received identical total scores, scores were also independent of the number of children in the family and of ordinal position, and mothers returned higher scores than fathers.

Adolescents with Asperger syndrome (AS: without delay in speech development, diagnosed according to ICD-10 clinical criteria) were compared with a group with high-functioning autism (HFA: all with delayed speech development), and a group with conduct disorder (CD). Family and genetic studies suggest that Asperger syndrome and autism form part of the same spectrum, whereas the social impairments in conduct disorder are assumed to have different origins. The aims were to explore the relationships between early speech development and other aspects of functioning in autistic disorders, and to compare autistic and nonautistic social impairments. Early and current behaviour and IQ profiles were investigated.The CD group were clearly different from both the AS and HFA groups. The AS group tended to have less severe early behavioural abnormalities than the HFA group, and were unlikely to have speech abnormalities, but other communicative, social, and restricted/stereotyped behavioural difficulties were largely of a similar pattern to the abnormalities in the HFA group. Eighty per cent of the AS group met criteria for autism on the diagnostic algorithm associated with the Autism Diagnostic Interview-Revised. By adolescence, the AS group were reported to be as abnormal as the HFA group but in structured 1:1 interaction their conversation was better. IQ profile in the AS group showed relative strength on verbal measures, unlike the HFA group, but relatively good performance on the Block Design subtest of the WISC/WAIS was a feature of both the AS and HFA groups. The results indicate closely similar behavioural manifestations may arise by adolescence despite differences in speech development. Follow-up studies and further family investigations will be required to clarify the origins of these and other patterns of autistic development.

In 1997 in this Journal we published the “Reading the Mind in the Eyes” Test, as a measure of adult “mentalising”. Whilst that test succeeded in discriminating a group of adults with Asperger syndrome (AS) or high-functioning autism (HFA) from controls, it suffered from several psychometric problems. In this paper these limitations are rectified by revising the test. The Revised Eyes Test was administered to a group of adults with AS or HFA (N = 15) and again discriminated these from a large number of normal controls (N = 239) drawn from different samples. In both the clinical and control groups the Eyes Test was inversely correlated with the Autism Spectrum Quotient (the AQ), a measure of autistic traits in adults of normal intelligence. The Revised Eyes Test has improved power to detect subtle individual differences in social sensitivity.

Memory tasks were administered to 14 high-functioning individuals with autism and 14 typically developing individuals matched on chronological age and verbal intelligence. The tasks consisted of free and cued recall of 15 semantically unrelated words in 3 encoding conditions: phonological encoding, semantic encoding, and a no encoding orientation. In both groups, semantic orientation led to better free recall than did orientation toward syllabic encoding or absence of orientation. In contrast, semantic cues at retrieval led to better cued recall than phonological cues in typically developing individuals, whereas both types of cue had the same effect in prompting cued recall for individuals with autism. These findings are incompatible with the hypothesis of an amnesic deficit and do not support the notion of executive or semantic deficits in the memory problems of autistic individuals, at least for those with a high level of functioning. It is proposed that these findings can be accounted for by enhanced phonological processing in autism. This interpretation is consistent with other findings of enhanced processing of low-level perceptual information in the visual and auditory modality in autism.

Executive functioning was investigated in 34 children (24 boys and 10 girls) with developmental language disorder (DLD) and 21 children (18 boys and 3 girls) with high-functioning autistic disorder (HAD) matched on Full Scale IQ, Nonverbal IQ, age (mean age 9 year, 1 month), and SES. The DLD group had a Verbal IQ that was 10 points higher than the HAD group. These children were given the Wisconsin Card Sorting Test (WCST), the Mazes subtest from the WISC-R, the Underlining test, and the Rapid Automatized Naming test. In addition, these children were given the Vineland Scales of Adaptive Functioning and the Wing Diagnostic Symptom Checklist in order to assess severity of autistic symptomatology. Results indicated that the only significant difference between the two groups on the cognitive tasks was perseverative errors on the WCST; there was no significant difference on total number of categories achieved or total number of errors on the WCST or on the other executive function measures. There was also significant overlap in the scores between the two groups and the difference in perseverative errors was no longer significant when Verbal IQ was partialled out. Executive functioning was strongly related to all IQ variables in the DLD group and particularly related to Verbal IQ in the HAD group. Although there was a relationship in the HAD group between executive functioning and adaptive functioning, as well as between executive functioning and autistic symptomatology, these relationships were generally no longer significant in the HAD group after the variance due to Verbal IQ was accounted for. The results are interpreted to indicate that although impaired executive functioning is a commonly associated feature of autism, it is not universal in autism and is unlikely to cause autistic behaviors or deficits in adaptive function.

Research using advanced but static mind-reading tests with high-functioning adults with a pervasive developmental disorder (PDD) provided evidence for subtle social cognitive deficits. In the present study, adults with PDD were unimpaired on such tasks, relative to individually matched normal controls. Significant differences between the two groups were, however, found on a more naturalistic empathic accuracy task developed for this study. Participants viewed two videotaped interactions that both depicted a male and female stranger having an initial conversation and were asked to infer the unexpressed thoughts and feelings of the four targets. Subjects with PDD performed significantly worse on the second video. These findings suggest that the mind-reading deficit of a subgroup of able adults with PDD may only be apparent when a sufficiently complex naturalistic assessment method is being used.