Sleep duration in preschool age and later behavioral and cognitive outcomes: an individual participant data meta-analysis in five European cohorts.

Short sleep duration has been linked to adverse behavioral and cognitive outcomes in schoolchildren, but few studies examined this relation in preschoolers. We aimed to investigate the association between parent-reported sleep duration at 3.5 years and behavioral and cognitive outcomes at 5 years in European children. We used harmonized data from five cohorts of the European Union Child Cohort Network: ALSPAC, SWS (UK); EDEN, ELFE (France); INMA (Spain). Associations were estimated through DataSHIELD using adjusted generalized linear regression models fitted separately for each cohort and pooled with random-effects meta-analysis. Behavior was measured with the Strengths and Difficulties Questionnaire. Language and non-verbal intelligence were assessed by the Wechsler Preschool and Primary Scale of Intelligence or the McCarthy Scales of Children's Abilities. Behavioral and cognitive analyses included 11,920 and 2981 children, respectively (34.0%/13.4% of the original sample). In meta-analysis, longer mean sleep duration per day at 3.5 years was associated with lower mean internalizing and externalizing behavior percentile scores at 5 years (adjusted mean difference: - 1.27, 95% CI [- 2.22, - 0.32] / - 2.39, 95% CI [- 3.04, - 1.75]). Sleep duration and language or non-verbal intelligence showed trends of inverse associations, however, with imprecise estimates (adjusted mean difference: - 0.28, 95% CI [- 0.83, 0.27] / - 0.42, 95% CI [- 0.99, 0.15]). This individual participant data meta-analysis suggests that longer sleep duration in preschool age may be important for children's later behavior and highlight the need for larger samples for robust analyses of cognitive outcomes. Findings could be influenced by confounding or reverse causality and require replication.

Associations of breastfeeding duration and cognitive development from childhood to middle adolescence.

AIM: To assess the dose-response association between the duration of any breastfeeding and cognitive skills in children from 5 to 15 years of age. METHODS: The data from the longitudinal cohort study Growing up in Australia: The Longitudinal Study of Australian Children (children born in 1999-2000 and 2003-2004) were accessed. Language skills were assessed via Peabody Picture Vocabulary Test at 5, 7 and 9 years of age (N = 8643), and non-verbal intelligence was assessed via Matrix Reasoning subtest from Wechsler Intelligence Scale at 7, 9 and 11 years of age (N = 8560) and executive functions were examined via Cogstate Cognitive Testing battery in 15 years old (N = 6213). Breastfeeding was assessed via maternal questionnaires, partly prospective. RESULTS: A longer duration of breastfeeding was significantly associated with greater language skills from 5 to 9 (0.05 [95% CI, 0.03-0.08], p < 0.0001) and greater non-verbal intelligence from 7 to 11 years of age (0.02 [95% CI, 0.01-0.04], p < 0.001). No significant relation was found between the breastfeeding duration and executive functions in 15 years old. CONCLUSION: These results support a dose-response relationship between breastfeeding duration and language skills and non-verbal intelligence during childhood and early adolescence.

Error analysis of Raven's Coloured Progressive Matrices in children and adolescents with cerebral palsy.

BACKGROUND: Analysis of the errors in the Raven's Coloured Progressive Matrices (RCPM) has been previously performed for children with intellectual disabilities but has not been investigated for those with cerebral palsy (CP). This study aimed to investigate whether the types and positions of errors made by individuals with CP differed from those made by typically developing (TD) controls. METHODS: Forty-five participants with CP aged 4-18 years and 30 TD children aged 3-9 years underwent RCPM testing. We first compared the RCPM performance and error characteristics between the groups and then examined the association between RCPM and the severity of CP and receptive vocabulary in the CP group. RESULTS: The results showed that while mean total scores in the two groups were comparable, the types and positions of errors made by individuals with CP differed from those of TD controls. The development of non-verbal intelligence in children with CP increased with age; when controlling for age, non-verbal intelligence was significantly correlated with all three functional levels of CP severity and receptive vocabulary. CONCLUSIONS: This study provides valuable insights into the problem-solving strategies employed by children with CP.

The Contribution of Visual and Auditory Working Memory and Non-Verbal IQ to Motor Multisensory Processing in Elementary School Children.

Although cognitive abilities have been shown to facilitate multisensory processing in adults, the development of cognitive abilities such as working memory and intelligence, and their relationship to multisensory motor reaction times (MRTs), has not been well investigated in children. Thus, the aim of the current study was to explore the contribution of age-related cognitive abilities in elementary school-age children (n = 75) aged 5-10 years, to multisensory MRTs in response to auditory, visual, and audiovisual stimuli, and a visuomotor eye-hand co-ordination processing task. Cognitive performance was measured on classical working memory tasks such as forward and backward visual and auditory digit spans, and the Raven's Coloured Progressive Matrices (RCPM test of nonverbal intelligence). Bayesian Analysis revealed decisive evidence for age-group differences across grades on visual digit span tasks and RCPM scores but not on auditory digit span tasks. The results also showed decisive evidence for the relationship between performance on more complex visually based tasks, such as difficult items of the RCPM and visual digit span, and multisensory MRT tasks. Bayesian regression analysis demonstrated that visual WM digit span tasks together with nonverbal IQ were the strongest unique predictors of multisensory processing. This suggests that the capacity of visual memory rather than auditory processing abilities becomes the most important cognitive predictor of multisensory MRTs, and potentially contributes to the expected age-related increase in cognitive abilities and multisensory motor processing.

Association between Non-Verbal Intelligence and Academic Performance of Schoolchildren from Taza, Eastern Morocco.

Interest in identifying factors influencing educational success is growing. It is often observed that a group of students share the same external variables (school environment) yet have different results, which states that individual variables have more impact on the determination of academic performance. Therefore, the present study aimed to substantiate this fact by investigating the association between non-verbal fluid intelligence and academic performance in a population of schoolchildren in Eastern Morocco. The investigation was a cross-sectional study based on a self-administered questionnaire. Items included the standard Raven's progressive matrices. Students' grades were collected from the administrative offices of the visited schools. Significant and positive correlations between the non-verbal intelligence scores and the school results were found: for the general average, the correlation was 0.574; for the school subject French, the correlation coefficient was 0.475; and for mathematics, we found a relatively low coefficient of 0.381. Non-verbal fluid intelligence significantly and positively predicted academic performance (ß = .574, p = .000). These results call for policymakers to implement the use of intelligence tests with school directors and teachers as a diagnostic tool to guide support efforts for low-achieving children and even to create pilot classes for the best-performing students.

Emotion Understanding in Bilingual Preschoolers.

The effects of bilingualism on child development have been extensively examined in last decades. Research reveals that simultaneous use of two or more languages affects child's language development, cognitive and social skills. The current study focuses on the so-far understudied theory of emotion understanding in bilingual children. A cohort of 593 bilingual and monolingual 5-6-year-olds took the Russian version of the Test of Emotion Comprehension (TEC) that assesses three components of emotion understanding: emotion understanding of external causes of emotions, reflective causes of emotions; and mental causes of emotions. Our results revealed no group differences between overall emotion understanding and understanding of external and reflective causes of emotions. However, monolingual children had a slightly better understanding of mental causes of emotions compared to bilingual children, when controlling for age, gender, and non-verbal intelligence. These results suggest that children growing up in bilingual environments might require more time and/or language/culture exposure to master the ability to understand mental causes of emotions, taking into account cultural differences, as well as the semantic and lexical differences in emotion labelling and emotion expression in each language.

Association of Health and Psychological Factors with Academic Achievement and Non-Verbal Intelligence in University Students with Low Academic Performance: The Influence of Sex.

Academic achievement, measured with the grade point average (GPA), is a stable characteristic that has been associated with many sociodemographic and psychological variables; however, the relation of these variables with GPA has not been totally elucidated. The objective of this study was to perform an association of health, psychological and personal variables with GPA and non-verbal intelligence in low-academic performance population according to sex. We invited health sciences university students who had failed the same subject twice to complete a set of sociodemographic and psychological variables and a non-verbal intelligence test. The GPA, admission exam test and preparatory GPA were obtained. We included 124 students, and found that GPA was associated with non-verbal intelligence in women but not in men; in whom, having a job and having a romantic partner, were more correlated. In women, positive relations with others, emotion perception and weekly physical activity hours were marginally correlated with GPA; while in men, emotion regulation and self-motivation had a tendency of correlation with GPA. In addition, we found that non-verbal intelligence was associated somatization and the number of diseases in women. Academic achievement is regulated by different variables in each sex; therefore, intervention programs addressed by sex are needed to increase it.

Domain-specific effects of prenatal fluoride exposure on child IQ at 4, 5, and 6-12 years in the ELEMENT cohort.

OBJECTIVE: Prenatal exposure to fluoride has been associated with adverse neurodevelopmental outcomes. However, the neuropsychological profile of fluoride's developmental neurotoxicity at low levels and the stability of this relationship across childhood has not been characterized. We investigated the longitudinal and domain specific effect of prenatal fluoride exposure on IQ among children ages 4, 5, and 6-12 years in the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) cohort. METHODS: We measured the average of maternal urinary fluoride at each trimester of pregnancy adjusted for creatinine (MUFCRE). Children were administered the McCarthy Scales of Children's Abilities at ages 4 (N = 386) and 5 (N = 308), and the Wechsler Abbreviated Scale of Intelligence at age 6-12 (N = 278). We used generalized estimating equation (GEE) models to estimate the population averaged effect of MUFCRE concentration on longitudinal General Cognitive Index (GCI)/Full-Scale IQ (FSIQ), Verbal IQ (VIQ), and Performance IQ (PIQ) scores (N = 348). We tested for possible interactions between MUFCRE and child sex as well as for MUFCRE and time point on children's IQ. All models controlled for relevant available covariates. RESULTS: The mean/median MUFCRE concentration was 0.90/0.83 mg/L (SD = 0.39; IQR, 0.64-1.11 mg/L). A 0.5 mg/L increase in MUFCRE predicted an average 2.12-point decrease in GCI/FSIQ (95% CI: -3.49, -0.75) and 2.63-point decrease in PIQ (95% CI: -3.87, -1.40). MUFCRE was marginally associated with VIQ across time (B = -1.29, 95% CI: -2.60, 0.01). No interactions between MUFCRE and child sex or MUFCRE and time were observed. CONCLUSION: The negative association between prenatal fluoride exposure and longitudinal IQ was driven by decrements in non-verbal intelligence (i.e. PIQ), suggesting that visual-spatial and perceptual reasoning abilities may be more impacted by prenatal fluoride exposure as compared to verbal abilities.

The Place of Gender Stereotypes in the Network of Cognitive Abilities, Self-Perceived Ability and Intrinsic Value of School in School Children Depending on Sex and Preferences in STEM.

Adolescents face many barriers on the path towards a STEM profession, especially girls. We examine the gender stereotypes, cognitive abilities, self-perceived ability and intrinsic values of 546 Russian school children from 12 to 17 years old by sex and STEM preferences. In our sample, STEM students compared to no-STEM have higher cognitive abilities, intrinsic motivation towards math and science, are more confident in their math abilities and perceive math as being easier. Boys scored higher in science, math and overall academic self-efficacy, intrinsic learning motivation and math's importance for future careers. Meanwhile, girls displayed higher levels of gender stereotypes related to STEM and lower self-efficacy in math. A network analysis was conducted to identify the structure of psychological traits and the position of the stem-related stereotypes among them. The analysis arrived at substantially different results when adolescents were grouped by sex or preference towards STEM. It also demonstrated that gender stereotypes are connected with cognitive abilities, with a stronger link in the no-STEM group. Such stereotypes play a more important role for girls than boys and, jointly with the general self-efficacy of cognitive and academic abilities, are associated with the factors that distinguish groups of adolescents in their future careers.

SON-R 6-40: dimensionalidade e validade convergente com a CMMS, TONI-3 e COM / SON-R 6-40: dimensionality and convergent validity with CMMS, TONI-3 and CPM / SON-R 6-40: dimensionalidad y validez convergente con CMMS, TONI-3 y CPM

O objetivo deste estudo foi avaliar a estrutura fatorial do teste não verbal de inteligência SON-R 6-40 e obter evidências de validade convergente deste com outros três instrumentos não verbais de inteligência: Matrizes Progressivas Coloridas de Raven, Escala de Maturidade Mental Colúmbia e TONI-3. Participaram do estudo 150 crianças de escolas públicas e privadas do Distrito Federal com idades entre 6 e 9 anos (M = 7,7; DP = 1,0). As análises fatoriais exploratórias indicaram uma estrutura com dois fatores para o SON-R 6-40 e uma estrutura unifatorial para os outros testes. Os dois fatores apresentaram uma correlação de 0,64 que explicam 68,3% da variância comum. Os coeficientes de correlação entre o SON-R 6-40 e os demais instrumentos variaram entre 0,62 e 0,73, com valor médio de 0,69. Os resultados indicam evidências adequadas da validade convergente do SON-R 6-40 com outros três testes não verbais de inteligência frequentemente utilizados no Brasil. (AU)

The aim of the study was to assess the factor structure of the non-verbal intelligence test SON-R 6-40 and obtain evidence of its convergent validity with three other non-verbal intelligence tests: Raven's Colored Progressive Matrices, Columbia Mental Maturity Scale and TONI- 3. Study participants were 150 children aged 6 to 9 years (M=7.7, SD=1.0) from public and private schools of the Federal District. Exploratory factor analysis indicated a two-factor structure for the SON-R 6-40 and a unidimensional structure for the three other tests. The two factors showed a correlation of .64 and together explained 68.3% of the common variance. The correlation coefficients between the SON-R 6-40 and the other instruments ranged between .62 and .73, with a mean value of .69. The results provide evidence of adequate convergent validity for the SON-R 6-40 with three other non-verbal intelligence tests frequently used in Brazil. (AU)

El objetivo del estudio fue evaluar la estructura factorial del test de inteligencia no verbal SON-R 6-40 y obtener evidencias de su validez convergente con otros tres instrumentos de inteligencia no verbal: el Test de Matrices Progresivas de Color de Raven, la Escala de Madurez Mental de Columbia y el TONI-3. En el estudio participaron 150 niños de 6 a 9 años de escuelas públicas y privadas del Distrito Federal (M = 7.7, DS = 1.0). El Análisis Factorial Exploratorio indicó una estructura de dos factores para el SON-R 6-40, y una estructura unifactorial para los otros tres tests. La correlación entre los dos factores fue de 0,64 y, lo que explica el 68.3% de la varianza común. Los coeficientes de correlación entre el SON-R 6-40 y los otros instrumentos fluctuaron entre 0,62 y 0,73 con una media de 0,69. Los resultados muestran evidencias adecuadas de la validez convergente del test SON-R 6-40 con los otros tres tests de inteligencia no verbal de uso frecuente en Brasil. (AU)

Executive Function, Working Memory, and Verbal Fluency in Relation to Non-Verbal Intelligence in Greek-Speaking School-Age Children with Developmental Language Disorder.

Developmental Language Disorder (DLD) is often associated with impairments in working memory (WM), executive functions (EF), and verbal fluency. Moreover, increasing evidence shows poorer performance of children with DLD on non-verbal intelligence tests relative to their typically developing (TD) peers. Yet, the degree and generality of relevant difficulties remain unclear. The present study aimed at investigating WM capacity, key EFs and verbal fluency in relation to non-verbal intelligence in Greek-speaking school-age children with DLD, compared to TD peers (8-9 years). To our knowledge, the present study is the first to attempt a systematic relevant assessment with Greek-speaking school-age children, complementing previous studies mostly involving English-speaking participants. The results showed that children with DLD scored lower than TD peers on the non-verbal intelligence measure. Groups did not differ in the inhibition measures obtained (tapping resistance to either distractor or proactive interference), but children with DLD were outperformed by TD peers in the WM capacity, updating, monitoring (mixing cost), and verbal fluency (phonological and semantic) measures. The effects showed limited (in the case of backward digit recall) or no dependence on non-verbal intelligence. Findings are discussed in terms of their theoretical and practical implications as well as in relation to future lines of research.

Perceptual reasoning skills mediate the relationship between attention and math proficiency in individuals with a neurodevelopmental condition.

BACKGROUND: An important component of academic success in typically developing students is the development of math skills, which is associated with attention and perceptual reasoning (PR) skills. For children with a neurodevelopmental condition (NDC), the relationship is confounded by diagnostic-specific cognitive characteristics. Specifically, enhanced PR is specific to individuals with Autism Spectrum Disorder (ASD). AIMS: The purpose of this study was to test: (i) a mediation model where PR skills would mediate the relationship between attention and math proficiency for students with an NCD, and (ii) whether this mediation model is moderated by a diagnostic profile. METHODS AND PROCEDURES: One hundred and thirty-seven students with an NDC participated in a school-based study examining the effectiveness of using a standardized measure of attention in predicting math capabilities. OUTCOMES AND RESULTS: PR mediated the relationship between attention and math proficiency for students diagnosed with an NDC. However, the model was not moderated by diagnostic profile. CONCLUSIONS AND IMPLICATIONS: The results of this study provide a better understanding of the roles of higher-level cognitive ability specific to students with NDCs. Additionally, the superior PR skills demonstrated by the ASD sample further supports the research suggesting this population possesses cognitive strengths in this domain.

Comparison of Expressive Spoken Language Skills in Children With Cochlear Implants and Children With Typical Hearing.

When children start formal education, they are expected to be able to express complex thoughts. However, in order to do so, they need to be able to use both complex grammatical structures and a variety of words. One group that is at risk of having a delay in terms of their expressive language ability is children with cochlear implants (CI). In this study, we evaluated whether children with CI perform comparably to children with typical hearing (TH) on a standard expressive spoken grammar and a standard expressive spoken vocabulary task when the groups were matched on non-verbal intelligence and working memory capacity. It was found that the children with CI in this study performed more poorly on a standard expressive spoken vocabulary task but not on a standard expressive spoken grammar task when compared to the children with TH. Differences in terms of expressive spoken vocabulary do not seem to be explained by differences in cognitive ability. In addition, the variation in terms of expressive spoken language ability was larger in the children with CI compared to the children with TH. This might be explained by additional confounding factors, like the time of language deprivation or by a greater influence of cognitive differences for the acquisition of spoken language for children with CI.

Genetic risk for Alzheimer disease in children: Evidence from early-life IQ and brain white-matter microstructure.

It remains unclear whether the genetic risk for late-onset Alzheimer disease (AD) is linked to premorbid individual differences in general cognitive ability and brain structure. The objective of the present study was to determine whether the genetic risk of late-onset AD is related to premorbid individual differences in intelligence quotient (IQ) and characteristics of the cerebral white-matter in children. The study sample included children of the Generation R Study from Rotterdam, The Netherlands. IQ was measured using a well-validated Dutch nonverbal IQ test (n = 1908) at ages 5 to 9 years. White-matter microstructure was assessed by measuring fractional anisotropy (FA) of white-matter tracts using diffusion tensor imaging (DTI) (n = 919) at ages 9 to 12 years. Genetic risk was quantified using three biologically defined genetic risk scores (GRSs) hypothesized to be related to the pathophysiology of late-onset AD: immune response, cholesterol/lipid metabolism and endocytosis. Higher genetic risk for late-onset AD that included genes associated with immune responsivity had a negative influence on cognition and cerebral white-matter microstructure. For each unit increase in the immune response GRS, IQ decreased by 0.259 SD (95% CI [-0.500, -0.017]). For each unit increase in the immune response GRS, global FA decreased by 0.373 SD (95% CI [-0.721, -0.026]). Neither cholesterol/lipid metabolism nor endocytosis GRSs were associated with IQ or cerebral white-matter microstructure. Our findings suggest that elevated genetic risk for late-onset AD may in part be manifest during childhood neurodevelopment through alterations in immune responsivity.

Auditory processing disorder evaluations and cognitive profiles of children with specific learning disorder.

OBJECTIVE: This study investigated the auditory sensory-perceptual level of specific learning disorder (SLD) and explored relationships among neuropsychological assessments for SLD, auditory processing, and short and long latencies of auditory event-related potentials (ERPs). METHODS: Fifteen children (7-14 years old) comprised the control group; 34 children comprised the SLD group. Audiologic assessments included tone audiometry, acoustic immittance measurements, acoustic reflex, central auditory processing, brainstem evoked response audiometry, and long latency potentials (P3 and N2). Children's intelligence levels were assessed with 2 intelligence batteries, 1 verbal and 1 non-verbal, as well as with visuomotor skills. RESULTS: Multiple regression showed a significant interaction effect of APE tests and P3/N2 over Wechsler Scale performance in freedom of distractibility indexes and multiple subtests. Errors in the Bender Visual Motor Gestalt Test were predicted by lower parental education, lower performance in APE tests: dichotic digits and pediatric/synthetic sentence identification-ipsilateral, and longer P3/N2 latencies, particularly regarding integration and rotation distortions. CONCLUSIONS: Children with altered auditory processing exhibit a specific cognitive profile, including lower verbal and spatial reasoning performance, that is sensitive to parental education level. SIGNIFICANCE: Children with SLD should undergo a complete multimodal examination to identify their specific difficulties and needs.

[Applicability of the SON-R 2-8 in Children with Special Educational Needs and Children with German as a Second Language]. / Zur Aussagekraft des SON-R 2-8 bei Kindern mit kognitiven Auffälligkeiten und Kindern mit Deutsch als Zweitsprache.

Applicability of the SON-R 2-8 in Children with Special Educational Needs and Children with German as a Second Language The SON-R 2-8 is an intelligence test that allows a non-verbal assessment of the general cognitive abilities of children with difficulties or limitations in the field of speech and language development and communication. The validity of the SON-R 2-8 in children with cognitive impairments and children with German as a second language is examined with matched groups. It is shown that the SON-R 2-8 can differentiate well between normal children and cognitive impaired children and is suitable for use in children with German as a second language.

Autistic Children Show a Surprising Relationship between Global Visual Perception, Non-Verbal Intelligence and Visual Parvocellular Function, Not Seen in Typically Developing Children.

Despite much current research into the visual processing style of individuals with Autism Spectrum Disorder (ASD), understanding of the neural mechanisms is lagging, especially with respect to the contributions of the overlapping dichotomies of magnocellular/parvocellular (afferent neural pathways), global/local (perception) and dorsal/ventral (cortical streams). Here, we addressed this deficiency by measuring inspection times (ITs) for novel global/local stimuli as well as recording nonlinear visually evoked potentials (VEPs), in particular, magnocellular and parvocellular temporal efficiencies. The study was conducted on a group of male ASD children and a typically developing (TD) group matched for mean age and mean non-verbal intelligence, as measured by the Raven's Progressive Matrices. The IT results did not differ between groups, however a negative correlation between global IT and Raven's score was found in the ASD group, that was not evident in the TD group. Nonlinear VEP showed the ASD group had smaller amplitude parvocellular-generated second order responses compared to the TD group. This is a sign of improved temporal responsiveness in ASD vs. TD groups. Principal Component Analysis linked global IT, non-verbal intelligence scores and VEP parvocellular efficiency in a single factor for the ASD but not the TD group. The results are suggestive of a constraint on pathways available for cognitive response in the ASD group, with temporal processing for those with ASD becoming more reliant on the parvocellular pathway.

Association of chronotype and social jetlag with human non-verbal intelligence.

The aim of this study was to evaluate the effects of chronotype and social jetlag (SJL) on intelligence. Subjects were aged 14-25 years (n = 1008). A significant effect of intelligence on academic performance, as measured by the Raven's Standard Progressive Matrices test, was found (F2,917 = 11.75, P < 0.0001, η2 = 0.03). When SJL was less than 2 hours, the intelligence of people with late chronotype was found to be higher than that of subjects with early and intermediate chronotypes (F2,305 = 3.12, P < 0.05, η2 = 0.02). A negative effect of SJL on the results of intelligence testing was noted only in subjects with late chronotype (F2,536 = 2.61, P < 0.05, η2 = 0.02). Our data suggest that people with late chronotype have a higher level of intelligence, but these advantages disappear when SJL ≥2 hours.

Comparison of Measures of Ability in Adolescents with Intellectual Disability.

Finding the most appropriate intelligence test for adolescents with Intellectual Disability (ID) is challenging given their limited language, attention, perceptual, and motor skills and ability to stay on task. The study compared performance of 23 adolescents with ID on the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV), one of the most widely used intelligence tests, and three non-verbal IQ tests, the Raven's Colored Progressive Matrices (RCPM), the Test of Non-verbal Intelligence-Fourth Edition and the Wechsler Non-verbal test of Ability. Results showed that the WISC-IV Full Scale IQ raw and scaled scores were highly correlated with total scores from the three non-verbal tests, although the correlations were higher for raw scores, suggesting they may lead to better understanding of within group differences and what individuals with ID can do at the time of assessment. All participants attempted more questions on the non-verbal tests than the verbal. A preliminary analysis showed that adolescents with ID without ASD (n = 15) achieved higher scores overall than those presenting with ID+ASD (n = 8). Our findings support the view that short non-verbal tests are more likely to give a similar IQ result as obtained from the WISC-IV. In terms of the time to administer and the stress for participants, they are more appropriate for assessing adolescents with ID.

School effects on non-verbal intelligence and nutritional status in rural Zambia.

This study uses hierarchical linear modeling (HLM) to examine the school factors (i.e., related to school organization and teacher and student body) associated with non-verbal intelligence (NI) and nutritional status (i.e., body mass index; BMI) of 4204 3rd to 7th graders in rural areas of Southern Province, Zambia. Results showed that 23.5% and 7.7% of the NI and BMI variance, respectively, were conditioned by differences between schools. The set of 14 school factors accounted for 58.8% and 75.9% of the between-school differences in NI and BMI, respectively. Grade-specific HLM yielded higher between-school variation of NI (41%) and BMI (14.6%) for students in grade 3 compared to grades 4 to 7. School factors showed a differential pattern of associations with NI and BMI across grades. The distance to a health post and teacher's teaching experience were the strongest predictors of NI (particularly in grades 4, 6 and 7); the presence of a preschool was linked to lower BMI in grades 4 to 6. Implications for improving access and quality of education in rural Zambia are discussed.