Family factors affecting child development.

In a large, geographically defined population of children a number of family factors in addition to social class, determined by the father''s occupation, were recorded by health visitors and school nurses with routine responsibility for these children. The quality of the children in normal schools was assessed in terms of nonverbal IQ and height at the ages of 5 and 10 years, and of behavior as reported by the teacher at the age of 10 years. By analysis of variance the sum of the independent effects of the other family factors greatly outweighed that of occupational social class, except in the case of the IQ at 10 years. The most important of the other family factors was the quality of the mother''s care of her child during the first 3 years of life.     

Effect on intelligence of relaxing the low phenylalanine diet in phenylketonuria.

A total of 599 children with phenylketonuria, who had been treated early, were followed up prospectively in order to examine the association between intellectual progress from 4 to 14 years of age and control of phenylalanine concentrations. The phenylalanine rose from around 400 mumol/l during the first four years to above 900 mumol/l by 12 years. The children were divided into two cohorts: cohort I comprised 224 children born in the United Kingdom between 1964 and 1971 and cohort II 375 children born between 1972 and 1978. In a previous study it was shown that by 4 years of age these children already had a mean intelligence quotient (IQ) over half a standard deviation below general population norms, and that IQ fell linearly as average phenylalanine concentrations rose. Multiple regression was used to estimate the size of the associations between IQ at later ages and average phenylalanine concentrations in the periods between assessments, after controlling for previous IQ and phenylalanine control, social class, type of phenylketonuria, and factors relating to diagnosis and early management. For each 300 mumol/l rise in average phenylalanine concentrations for those aged 5 to 8 years IQ at 8 years fell by 4-6 points. This compared with a 7-10 point fall in IQ at 4 years for a similar rise in phenylalanine. After 8 years of age the association between IQ and phenylalanine control disappeared in cohort I but persisted in cohort II and was significant up to 10 years of age, although the association was smaller than at 8 years.     

Intelligence and quality of dietary treatment in phenylketonuria.

The records of the Phenylketonuria Register were examined to determine the factors associated with early intellectual progress in children who had received a diet low in phenylalanine from soon after birth. A total of 1031 children were born between 1964 and 1980 and started treatment before they were 4 months of age, and 808 of them were followed up prospectively. In 263 children born between 1964 and 1971 (cohort 1), the mean intelligence quotient (IQ) at 4 years rose with year of birth from 24 points below revised IQ norms to 10 points below; in 545 born between 1972 and 1980 (cohort 2) there was no further rise in IQ and the mean remained eight points below the norms. IQ fell progressively by roughly four points for each four weeks'' delay in starting treatment, for each 300 mumol/l rise in mean phenylalanine concentrations during treatment, and for each five months during the first two years during which phenylalanine concentrations were below 120 mumol/l. Forty six children in cohort 2 had the most favourable treatment characteristics. Their mean IQ, after standardising for social class, was 112.6, and similar to the mean for the same group estimated by multiple regression, and to revised population IQ norms for the period during which the children were tested. The data suggest that many children who are treated early continue to suffer a mild degree of neurological impairment because of the difficulties in fully controlling the metabolic abnormality.     

Psychosocial determinants of behaviour problems in Brazilian preschool children

BACKGROUND: This investigation aimed at examining, through an epidemiological study, the social demographic, family and individual determinants of behaviour problems in preschool children. METHOD: Six hundred and thirty-four children, age four years, and their mothers, belonging to a cohort of 5,304 children being followed from birth, took part in the study. During a home visit, the child's behaviour problems and IQ were examined, as well as the prevalence of maternal psychiatric disorder, the quality of the home environment, and other social demographic, family and individual factors. RESULTS: The results revealed a prevalence of children's behaviour problems of 24% (clinical and borderline groups). Regression analysis showed that maternal psychiatric disorder, education and age, number of younger siblings and quality of the home environment explained 28% of the variance of the child's behaviour problems. CONCLUSIONS: The results point to the multi-determination of child behaviour problems.     

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.     

Dietary patterns in infancy and cognitive and neuropsychological function in childhood

Background: Trials in developing countries suggest that improving young children’s diet may benefit cognitive development. Whether dietary composition influences young children’s cognition in developed countries is unclear. Although many studies have examined the relation between type of milk received in infancy and subsequent cognition, there has been no investigation of the possible effect of variations in the weaning diet. Methods: We studied 241 children aged 4 years, whose diet had been assessed at age 6 and 12 months. We measured IQ with the Wechsler Pre‐School and Primary Scale of Intelligence, visual attention, visuomotor precision, sentence repetition and verbal fluency with the Developmental Neuropsychological Assessment (NEPSY), and visual form‐constancy with the Test of Visual Perceptual Skills. Results: In sex‐adjusted analyses, children whose diet in infancy was characterised by high consumption of fruit, vegetables and home‐prepared foods (‘infant guidelines’ dietary pattern) had higher full‐scale and verbal IQ and better memory performance at age 4 years. Further adjustment for maternal education, intelligence, social class, quality of the home environment and other potential confounding factors attenuated these associations but the relations between higher ‘infant guidelines’ diet score and full‐scale and verbal IQ remained significant. For a standard deviation increase in ‘infant guidelines’ diet score at 6 or 12 months full‐scale IQ rose by .18 (95% CI .04 to .31) of a standard deviation. For a standard deviation increase in ‘infant guidelines’ diet score at 6 months verbal IQ rose by .14 (.01 to .27) of a standard deviation. There were no associations between dietary patterns in infancy and 4‐year performance on the other tests. Conclusions: These findings suggest that dietary patterns in early life may have some effect on cognitive development. It is also possible that they reflect the influence of unmeasured confounding factors.     

Prediction of intellectual deficits in children with acute lymphoblastic leukemia

Possible predictors of reported lower cognitive functioning in irradiated children with acute lymphoblastic leukemia (ALL) were investigated. Thirty-four subjects, 5-14 years old, with ALL in continuous complete remission and without evidence of current or past central nervous system disease, were examined 9-110 months after diagnosis, using standard measures of intelligence and academic achievement. Subjects with a history of post-irradiation somnolence syndrome were significantly older at diagnosis than nonsomnolent subjects. Intelligence (IQ) was found to be unrelated to history of somnolence syndrome. IQ and achievement were unrelated to age at irradiation, irradiation-examination interval, and radiation dosages. The strongest predictor of IQ by far is parental social class. The importance of controlling for social class differences when searching for treatment effects on IQ and achievement is stressed.     

Wechsler subscale IQ and subtest profile in early treated phenylketonuria.

AIM: Mildly depressed IQ is common in treated phenylketonuria. This study explored whether a particular intellectual ability profile typifies early and continuously treated phenylketonuria and whether component skills comprising the IQ relate to socioeconomic and treatment factors. METHODS: IQ scores were collected retrospectively from variants of the "Wechsler intelligence scale for children" performed at age 8 on 57 children with early treated, classic phenylketonuria. The mental ability pattern underlying IQ was investigated by analysing subscale and subtest scores and dietary factors, such as historical phenylalanine blood concentrations. RESULTS: The children's mean full scale IQ of 91.11 was significantly below the healthy population norm. There was a significant discrepancy between their mean verbal IQ (94.65) and mean performance IQ (89.42), suggestive of a spatial deficit, but the data did not support a biochemical or sociological explanation. Individual Wechsler subtests had no distinctive pattern. Phenylalanine control at age 2 was predictive of overall IQ. At this age, children with annual median phenylalanine < 360 micromol/litre (recommended UK upper limit) had a mean IQ 10 points higher than those above. CONCLUSIONS: Early and continuous treatment of phenylketonuria does not necessarily lead to normalisation of overall IQ. Verbal intelligence in the primary school years appears to normalise if blood phenylalanine is maintained below 360 micromol/litre in infancy, but spatial intelligence may remain poor. However, the discrepancy in skill development is not the result of social status or treatment variables. Perhaps weak spatial intelligence is an ancillary effect of a protective rearing style occasioned by the dietary treatment regimen.     

Individual differences in young children's IQ: a social-developmental perspective

From a sample of middle-class mothers and their 3-year-old children, a selected group of 36 mothers were divided into 2 groups according to the quality of their responses to the Adult Attachment Interview as a Questionnaire (Crandell, Fitzgerald, & Whipple, 1997). Twenty mothers provided coherent accounts of their early parent-child relationships (secure) and 16 mothers provided idealised, entangled, or otherwise incoherent accounts of their early parent-child relationships (insecure). The mothers were administered an abbreviated version of the WAIS-R and the children were given an abbreviated version of the Stanford-Binet Intelligence Scale. The quality of mother-child interactions was assessed by videotaping a 20-minute play episode and clean-up period, and by rating the degree of synchrony according to a modified version of the Belsky Parent-Child Interaction System (Whipple, Denburg, & Davies, 1993). The results were that children of secure mothers scored 19 points higher on the Stanford-Binet test compared to children of insecure mothers. (The adjusted mean difference was 12 points when maternal IQ, education, and family SES were taken into account.) The group difference in the children's IQ remained significant when comparisons were made between a subgroup of 12 secure and 12 insecure mothers who were matched for maternal IQ. Finally we examined the subgroup of 16 cases where child IQ scores were either 10 points higher or lower than maternal IQ. In all 6 cases where child IQ was at least 10 points below maternal IQ, the child had a mother who was insecure; in contrast, only 4 of the 10 children who had IQ scores 10 points higher than maternal IQ had an insecure mother. In terms of parent-child interaction patterns, there was suggestive evidence that the degree of parent-child synchrony was also related to child IQ. The results suggest important social-developmental contributions to young children's performance on standardised tests of intellectual ability.     

The psychological development of children from Belarus exposed in the prenatal period to radiation from the Chernobyl atomic power plant

This study examined psychological development in 138 children at the age of 6-7 and 10-11 years, who had suffered prenatal radiation exposure at the time of the Chernobyl accident in 1986. These children were compared to a control group of 122 children of the same age from noncontaminated areas of Belarus. The examination included neurological and psychiatric examination, intellectual assessment, and clinical psychological investigation of parents as well as the estimation of thyroid exposure in utero. The exposed group manifested a relative increase in psychological impairment compared with the control group, with increased prevalence in cases of specific developmental speech-language disorders (18.1% vs. 8.2% at 6-7 years; 10.1% vs. 3.3% at 10-11 years) and emotional disorders (20.3% vs. 7.4% at 6-7 years; 18.1 vs. 7.4% at 10-11 years). The mean IQ of the exposed group was lower than that of the control group, and there were more cases of borderline IQ (IQ = 70-79) (15.9% vs. 5.7% at 6-7 years; and 10.1% vs. 3.3% at 10-11 years). The mean value of thyroid doses from 131I 0.4 Gy was estimated for children exposed in utero. No correlation was found between individual thyroid doses and IQ at age 6-7 years or 10-11 years. We notice a positive moderate correlation between IQ of children and the educational level of their parents. There was a moderate correlation between high personal anxiety in parents and emotional disorders in children. We conclude that a significant role in the genesis of borderline intellectual functioning, specific developmental disorders of speech, language and scholastic skills, as well as emotional disorders in the exposed group of children was played by unfavourable social-psychological and social-cultural factors such as a low educational level of parents, the break of microsocial contacts, and adaptational difficulties, which appear following the evacuation and relocation from the contaminated areas.     

Parental factors in cognitive outcome of non-handicapped low birthweight infants.

A population based cohort of 144 children weighing less than 2000 g who were without major handicap, and a random control sample of 163 children born at term and weighing over 3000 g were investigated. The aim was to assess the relative importance for cognitive development at 5 years of age, of birthweight, parental demographic factors, and factors related to the environment in which the child was reared. The mean non-verbal IQ was 6.1 points lower (95% CI, 2.3 to 10) for the low birthweight (LBW) group, but the difference was reduced to 4.8 points (95% CI, 1.1 to 8.5) after adjusting for confounding parental demographic and childrearing factors. The verbal IQ was similar for the two groups after such adjustment. Paternal education was the main confounding variable, and demographic factors such as parental education and family income were much stronger predictors of child IQ than birthweight or factors related to the childrearing environment. There was no evidence that the cognitive development of low birthweight children was more sensitive to a non-optimal childrearing environment than that of normal birthweight children. These findings indicate that the risk of impaired cognitive development increases with decreasing socioeconomic status, and that this risk is much larger than, and independent of, the small risk attributable to low birthweight.     

Educational and social characteristics of children with asthma

Asthma was found to affect 4·8% of Aberdeen schoolchildren aged 10 to 15 years, the ratio of affected boys to girls being 2·2:1.In the majority of children, asthma caused frequent absence from school in the early years: at the time of the study there was still some adverse effect on education in half of the children with severe asthma but in only a minority of those with moderate or mild asthma.There was an excess of severe asthma in the children of semi- and unskilled manual workers (social classes IV and V). Children with severe asthma tended to come from large families, regardless of social class.The children with asthma had a higher mean IQ than the general study population.     

Are there critical periods for brain growth in children born preterm?

BACKGROUND: Children born very preterm who attend mainstream schools have a high prevalence of minor motor, behavioural, and learning disorders. These appear to be associated with reduced postnatal growth, particularly of the head. It is unclear when this poor growth occurs and whether growth restriction during different periods has different effects on later function. OBJECTIVE: To identify periods during early development, in children born preterm, when impaired head growth may influence minor motor and cognitive function. POPULATION: A geographically defined cohort of 194 infants born in Merseyside during 1980-81 and weighing less than 1500 g. METHODS: Measurements of head circumference (occipitofrontal circumference (OFC)) were available at birth, hospital discharge, 4 years, and 15 years of age. Assessments of intelligence (intelligence quotient (IQ)) and minor motor impairment (test of motor impairment (TOMI)) were made at 8 years of age. Clinical, social, and demographic variables were obtained from the clinical record and maternal interviews. RESULTS: IQ correlated significantly with OFC at 4 and 15 years of age after correction for growth restriction at birth (intrauterine growth restriction (IUGR)) and social class. TOMI scores correlated significantly with OFC at all four times, but especially with OFC at discharge and with change in OFC between birth and discharge. They were not affected by correction for social class or IUGR. CONCLUSION: Although both IQ and minor motor impairments correlate strongly with each other at school age in very low birthweight children, the factors determining them and their timing of operation are different. Interventions designed to improve IQ in this population would need to reduce IUGR and improve later childhood growth. Those aimed to improve motor ability need to be targeted more at brain protection during the neonatal period.     

Eight-year-old very and extremely preterm children showed more difficulties in performance intelligence than verbal intelligence

Aim

This study determined possible discrepancies between verbal IQ and performance IQ in 8-year-old very preterm (VPT) and extremely preterm (EPT) children, and examined associations between verbal IQ and performance IQ, and sociodemographic factors, perinatal factors, early cognitive outcomes and also with school achievement scores.

Methods

This prospective cohort study included 120 eight-year-old VPT/EPT children. Cognitive development was assessed at the ages of 2, 5 and 8 years. Eight years’ school achievement results in arithmetic, reading and spelling were collected. Multiple regression analyses were performed to determine predictors of verbal IQ and performance IQ at the age of 8 years and to determine associations with school achievement scores.

Results

Mean performance IQ (89.8) was significantly lower than mean verbal IQ (99.4; Cohen's d = 0.59) at the age of 8 years. Gestational age (GA), small for GA status, and cognitive scores at the ages of 2 and 5 years significantly predicted verbal IQ and performance IQ at the age of 8 years. Performance IQ at age 8 years was an important predictor for arithmetic scores (β = 0.42).

Conclusion

Performance IQ was more strongly affected than verbal IQ in 8-year-old VPT/EPT children and was strongly related to mathematical difficulties.

     

The Social Environmental Correlates of Reading Ability

The influences of social and family characteristics on individual differences in reading and spelling ability and IQ were investigated for 550 twin children aged 13 yrs. Measures of family social circumstances, parental background, the emotional atmosphere at home and the family's reading behaviour were used as predictor variables in multiple regression analyses with reading, spelling and IQ as dependent variables. There were consistent relationships between many of these measures and the dependent variables. The findings are compared to a previous biometrical genetic analysis of the same data set. It is concluded that the results are within the limits predicted by the genetic analysis. Most of the effect of these environmental influences on children are general, i.e. related to IQ, and not specifically related to reading. After controlling for the effects of IQ on reading, only family size and some aspects of parent-child relationships were significant predictors of reading ability.     

Congenital Hypothyroidism: Physiological and Psychological Factors in Early Development

Children diagnosed as congenitally hypothyroid and treated from a very early age were followed up at 1 and 3 years. At 1 year they seemed to be developing normally, unless they were undertreated or had an additional disorder. There were no significant correlations between biochemical or social factors and psychological outcome at 1 year. At 3 years, however, those children whose T4 and/or T3 had been very low initially had significantly lower IQ scores than both other hypothyroid children and matched controls. Children with only moderately low initial T4 and/or T3, however, were doing just as well as their matched controls. Initial levels of TSH, the number of symptoms at first clinical interview and the age at the start of treatment were not good indicators of ability at 3 years. Undertreatment was rare but did appear to affect ability. Psychological outcome at 3 years was also correlated with social class (for both cases and controls). Multiple regression analyses indicated that both low initial T4 (less than 20 nmol/l) and social class contributed significantly to outcome.     

Social competence and behavior problems in premature children at school age

Social competence and behavior problems of 87 children born weighing less than 1501 g were measured using the Child Behavior Checklist when the children were 7 to 8 years old. Both premature boys and girls had significantly lower Social Competence scores than the normative samples of their respective sexes. Only premature boys had significantly higher Behavior Problems scores, with significantly higher scores on behaviors associated with conduct disorders. Premature children in each of three social class groups had significantly lower Social Competence scores and higher Behavior Problems scores than normative children. Furthermore, there was an interaction between prematurity and social class on Behavior Problems scores, with the greatest discrepancy in scores between premature and normative children in the lower-class group. Relative to other predictors, IQ score best explained Social Competence scores and family stability best explained Behavior Problems scores in the premature sample.     

Effect of dietary non-compliance on development in phenylketonuria--studies of 14-year-old patients

25 children with early treated PKU were studied at the age of 14 years. The IQ was higher at the age of 6-8, 10 and 14 years if the dietary control was good (75% of the control values up to 10 mg/dl) compared to children with poor control. The IQ however decreased up to the age of 14 years in both groups. Discontinuation of the diet in children with a good dietary control at the age of 6 years because of a normal EEG after phenylalanine loading causes a decrease of the IQ from 100 at 6 years to 90 at 10 years. The IQ remains stable thereafter up to 14 years. The IQ ist lower at the age of 7 or 8 years in those children in whom the discontinuation of diet is delayed because of abnormal EEG after phenylalanine loading at the age of 6 years, but remains stable up to the age of 14. According to these results a discontinuation of the diet at the age of 6 years can not be recommended even if the EEG is normal after phenylalanine load.     

Children with superior intelligence at 7 years of age: a prospective study of the influence of perinatal, medical, and socioeconomic factors.

Perinatal and medical information, growth, and the social background of 258 children who, in a prospective study, had superior intelligence at 7 years of age were reviewed. The subjects were divided into three categories on the basis of the results of psychological evaluation at age 7. Comparisons were made between those with superior (intelligence quotient greater than or equal to 120), average (IQ between 80 and 119), and low intelligence (IQ less than or equal to 79). A favorable parental social and educational background was the best correlate of superior intelligence in the children. Larger head size from 1 year of age was an early finding associated with superior intelligence. Greater height and weight, from 4 years of age were later findings. Correlations between psychological performance at ages 4 and 7 years were statistically significant. Perinatal factors and medical complications did not affect the intellectual status of children with superior intelligence.     

Biology versus environment in low birth weight children

OBJECTIVE: To explore the contribution of biologic risk factors versus socio-demographic and environmental risk factors in cognitive development of children with birth weight less than 2000 g, at the age of 12 years. DESIGN: Prospective cohort study. SETTING: Infants discharged from a NICU of a referral hospital, with birth weight less than 2000 g between 1987-89 and followed up in the High Risk Clinic. METHODS: The children were assessed at the age of 12 years, with the Weschlers Intelligence Scale for IQ and by Wide Range Achievement Test for mathematics skills. Mothers education, fathers education, socio-economic status, family structure, spaciousness of the house, the locality in which the child lived and the type of school the child attended, were all recorded. A stimulation score was determined at 6 and 12 months and 3 years. Family environment score was used at 12 years. RESULTS: The cohort consisted of 180 children, with 90 controls. The mean IQ of the study group was 89.5 +- 16.9, which was significantly lower than that of controls (97.2 +- 14.1) (P lessthan 0.05). The mathematical skills of the study group were significantly poorer (P lessthan 0.05) than that of controls. A multiple linear regression analysis was done using IQ as the dependent variable and all risk factors at birth, stimulation scores and socio-environmental factors as independent variables. Mothers education was the most important factor contributing to the total IQ, a variance of 25.2percent of the total variance 44.2 PERCENT. Fathers education emerged as an important factor for mathematics skills. School was the next important factor for IQ as well as academics. Controlling for all other background factors, birth weight was the only biologic factor of significance, and this had a very small contribution. CONCLUSION: Parental education and the type of school attended by the child were the most important factors influencing cognitive development. The only biologic factor of importance was birth weight, but this too had a very small contribution.