Information processing abilities in twins reared apart

A battery of information processing measures and psychometric tests of specific and general cognitive abilities was administered to a sample of 105 individuals which included 34 monozygotic and 13 dizygotic reared apart twin pairs or triplets. Correlations between information processing parameters and psychometric abilities as well as twin resemblances for the information processing parameters were examined. In a principal components analysis of the information processing parameters, three components were identified which accounted for 67% of the total variation; Overall Speed of Response (OSR), Speed of Information Processing (SIP), and Speed of Spatial Processing (SSP). OSR was significantly correlated with WAIS IQ, and psychometric measures of verbal reasoning, spatial ability, and perceptual speed and accuracy. SIP was significantly correlated with WAIS IQ, measures of verbal reasoning, and one of the perceptual speed and accuracy measures. SSP was significantly correlated with measures of both spatial ability and perceptual speed and accuracy. Due to the small size of the dizygotic twin sample, no strong conclusions could be drawn regarding the magnitude of their resemblance. The correlation between component scores of reared apart monozygotic twins was significant for OSR, but not for SIP or SSP.     

More Than Just IQ: School Achievement Is Predicted by Self-Perceived Abilities—But for Genetic Rather Than Environmental Reasons

ABSTRACT— Evidence suggests that children's self-perceptions of their abilities predict their school achievement even after one accounts for their tested cognitive ability (IQ). However, the roles of nature and nurture in the association between school achievement and self-perceived abilities (SPAs), independent of IQ, is unknown. Here we reveal that there are substantial genetic influences on SPAs and that there is genetic covariance between SPAs and achievement independent of IQ. Although it has been assumed that the origins of SPAs are environmental, this first genetic analysis of SPAs yielded a heritability of 51% in a sample of 3,785 pairs of twins, whereas shared environment accounted for only 2% of the variance in SPAs. Moreover, multivariate genetic analyses indicated that SPAs predict school achievement independently of IQ for genetic rather than environmental reasons. It should therefore be possible to identify "SPA genes" that predict school achievement independently of "IQ genes."     

Examining the association between music lessons and intelligence

Although links between music training and cognitive abilities are relatively well-established, unresolved issues include the generality of the association, the direction of causation, and whether the association is mediated by executive function. Musically trained and untrained 9- to 12-year olds were compared on a measure of IQ and five measures of executive function. IQ and executive function were correlated. The musically trained group had higher IQs than their untrained counterparts and the advantage extended across the IQ subtests. The association between music training and executive function was negligible. These results provide no support for the hypothesis that the association between music training and IQ is mediated by executive function. When considered jointly with the available literature, the findings suggest that children with higher IQs are more likely than their lower-IQ counterparts to take music lessons, and to perform well on a variety of tests of cognitive ability except for those measuring executive function.     

Accounting for the shared environment in cognitive abilities and academic achievement with measured socioecological contexts

Behavioral and molecular genetic research has established that child cognitive ability and academic performance are substantially heritable, but genetic variation does not account for all of the stratification of cognitive and academic outcomes across families. Which specific contexts and experiences contribute to these shared environmental influences on cognitive ability and academic achievement? Using an ethnically and socioeconomically diverse sample of N = 1728 twins ages 7–20 from the Texas Twin Project, we identified specific measured family, school, and neighborhood socioecological contexts that statistically accounted for latent shared environmental variance in cognitive abilities and academic skills. Composite measures of parent socioeconomic status (SES), school demographic composition, and neighborhood SES accounted for moderate proportions of variation in IQ and achievement. Total variance explained by the multilevel contexts ranged from 15% to 22%. The influence of family SES on IQ and achievement overlapped substantially with the influence of school and neighborhood predictors. Together with race, the measured socioecological contexts explained 100% of shared environmental influences on IQ and approximately 79% of shared environmental influences on both verbal comprehension and reading ability. In contrast, nontrivial proportions of shared environmental variation in math performance were left unexplained. We highlight the potential utility of constructing “polyenvironmental risk scores” in an effort to better predict developmental outcomes and to quantify children's and adolescents’ interrelated networks of experiences. A video abstract of this article can be viewed at: https://youtu.be/77E_DctFsr0     

Are visual-perceptual and visual-motor skills separate abilities?

This study explored the independence of visual-perceptual and visual-motor abilities. Scores on the Motor-free Visual Perception Test were correlated by Pearson's method with scores on tests that weight the visual-perceptual, motor, and visual-motor components differently. Small but significant correlations were found between the Motor-free Visual Perception Test and tests of visual-motor integration, but there was no relationship between the motor-free test and tests of motor ability. These findings support the premise that tests of visual perception, visual-motor integration, and motor ability measure different skills.     

Is body mass index in old age related to cognitive abilities? The Lothian Birth Cohort 1936 Study

We tested the hypothesis that the previously reported association between a higher body mass index (BMI) and poorer cognition in later adulthood is an artifact of confounding by previous cognitive ability and socioeconomic status. Participants were 1,079 adults aged about 70 years in the Lothian Birth Cohort 1936 Study, on whom there are IQ data from age 11. Cognitive outcome measures included: IQ at age 70 using the same test that was administered at age 11; composite measures of general cognitive ability (g factor), speed of information processing, and memory; and two tests of verbal ability. People classified as overweight or obese in later adulthood had significantly lower scores on tests of childhood IQ, age 70 IQ, g factor, and verbal ability. There was no significant association with processing speed or memory performance. After adjusting for childhood IQ and social class in general linear models, associations with age 70 IQ and g factor were nonsignificant or attenuated. However, throughout the models, there was a persistent (inverse) relationship between BMI and performance on the National Adult Reading Test (NART) and Wechsler Test of Adult Reading (WTAR), which remained significant after full adjustment for all sociodemographic and health covariates (for the NART, p = .025; for the WTAR, p = .011). The findings suggest that the previously reported BMI-cognition associations in later adulthood could be largely accounted for by prior ability and socioeconomic status, and by the possible influence of these factors on the adoption of health behaviors in adulthood.     

A parent-offspring adoption study of cognitive abilities in early childhood

Do cognitive abilities in early childhood relate genetically and/or environmentally to isomorphic abilities in adulthood? Are specific cognitive abilities diffentiated in early childhood in terms of their prediction of adult cognitive abilities? The present study, the first behavioral genetic analysis of specific cognitive abilities in early childhood, explored these questions using parent-offspring data for 186 adopted children and 151 nonadopted children tested in the longitudinal Colorado Adoption Project at 3 years of age and 162 adopted children and 138 nonadopted children tested at 4 years. The children's Stanford-Binet IQ and scores for four specific cognitive abilities (verbal, spatial, perceptual speed, and memory) were correlated with corresponding measures for their parents—the biological and adoptive parents of the adopted children and the natural parents of the nonadopted children. Significant correlations were found between biological mothers' IQ and the IQ of their adopted away offspring at 3 and 4 years of age, suggesting genetic influence for IQ. However, specific cognitive abilities yielded no significant correlations between biological mothers and their adopted-away offspring. These results suggest that substantial genetic continuity exists for IQ from early childhood to adulthood, but not for specific cognitive abilities.     

Cerebellar tasks do not distinguish between children with developmental dyslexia and children with intellectual disability.

This paper explored the claim that only children with developmental dyslexia, whose reading ability is discrepant from their average general reasoning ability show specific deficits in motor tasks assessing cerebellar functioning (Fawcett et al., 2001, Cerebellar tests differentiate between groups of poor readers with and without IQ discrepancy. J. Learning Disabilities, 34, 119) and rapid serial naming (RAN, Wolf & Bowers, 1999, The double deficit hypothesis for the developmental dyslexias. J. Educ. Psychol., 91, 1). All available children between the ages of 11 and 14 were recruited from two special schools for children with either (a) formally-diagnosed intellectual disabilities (N = 18); or (b) formal diagnoses of developmental dyslexia (N = 25). These two groups of children did not differ on gender, age, pseudoword decoding abilities, or on 7 of 8 literacy measures, but did differ significantly, as expected on verbal and non-verbal reasoning tasks. Importantly, there were no deficits in bead threading ability or postural stability in the children with developmental dyslexia compared to the children with intellectual disabilities. There were also no between-group differences in rapid naming measures. The present results therefore provide no support for the claim that cerebellar deficits or RAN distinguish between children with dyslexia and children with intellectual disabilities that include reading.     

Gender and its contribution to the prediction of cognitive abilities at 5 years

Gender-related differences in the prediction of five year-olds' cognitive abilities from measures of distal environment, proximal environment and infant test scores were examined in a random sample of 93 boys and 90 girls. Distal environmental data included maternal IQ, maternal and paternal education. Proximal environmental data included two variables derived from the Home Screening Questionnaire: the Home Questions and the Toy Checklist. The Bayley MDI was administered at age 13 months, whereas WPPSI-R was used as cognitive outcome measure at age 5 years. The relationship between paternal education and child IQ, and between proximal environmental variables and child IQ was significantly stronger for boys than for girls. The associations between proximal environment and IQ in boys, were accounted for by the distal environmental variables. Bayley MDI correlated significantly higher with girls' IQ compared to boys' IQ. Findings are discussed in terms of parental gender-differentiated socialization processes.     

Cognitive processes in children's reading and attention: The role of working memory,divided attention,and response inhibition

Children experiencing attention difficulties have documented cognitive deficits in working memory (WM), response inhibition and dual tasks. Recent evidence suggests however that these same cognitive processes are also closely associated with reading acquisition. This paper therefore explores whether these variables predicted attention difficulties or reading among 123 children with and without significant attention problems sampled from the school population. Children were screened using current WM and attention task measures. Three factors explained variance in WM and attention tasks. Response inhibition tasks loaded mainly with central executive measures, but a dual processing task loaded with the visual‐spatial WM measures. Phonological loop measures loaded independently of attention measures. After controls for age, IQ and attention‐group membership, phonological loop and ‘central processing’ measures both predicted reading ability. A ‘visual memory/dual‐task’ factor predicted attention group membership after controls for age, IQ and reading ability. Results thus suggest that some of the processes previously assumed to be predictive of attention problems may reflect processes involved in reading acquisition. Visual memory and dual‐task functioning are, however, purer indices of cognitive difficulty in children experiencing attention problems.     

Intellectual functioning of deaf adults and children: Answers and questions

Intelligence has long been seen as linked to the spoken and written word. Because most deaf people have poor spoken language skills and find reading a significant challenge, there is a history in both psychology and education of considering deaf individuals to be less intelligent or less cognitively flexible than hearing individuals. With progress in understanding natural signed languages and cognitive abilities of individuals who lack spoken language, this perspective has changed. We now recognise, for example, that deaf people have some advantages in visuospatial ability relative to hearing people, and there is a link between the use of natural signed languages and enhanced visuospatial abilities in several domains. Such findings contrast with results found in memory, where the modality of mental representation, experience, and organisation of knowledge lead to differences in performance between deaf and hearing individuals, usually in favour of the latter. Such findings demonstrate that hearing loss and use of a natural sign language can influence intellectual abilities, including many tapped by standardised IQ tests. These findings raise interesting questions about the place of spoken language in our understanding of intelligence and ways in which we can use basic research for applied purposes.     

Constructive thinking: a broad coping variable with specific components

The structure of constructive thinking and the development of an instrument for measuring it, the Constructive Thinking Inventory (CTI), were discussed. Scales were derived from a factor analysis of an item domain of people's everyday automatic thinking. When the CTI and other tests were factor analyzed, separate intellective and nonintellective factors were found, with the CTI loading more strongly on the nonintellective factor than any other test. Only measures of IQ loaded on the intellective factor. The global constructive thinking scale correlated significantly with success in work, love, social relationships, and in maintaining emotional and physical well-being, but not with academic achievement, the only criterion with which the measures of IQ correlated strongly. The patterns of correlations between the CTI scales and the various criteria as well as the factor analysis demonstrated that the construct of constructive thinking is differentiated as well as integrated.     

Everyday cognition: age and intellectual ability correlates

The primary aim of this study was to examine the relationship between a new battery of everyday cognition measures, which assessed 4 cognitive abilities within 3 familiar real-world domains, and traditional psychometric tests of the same basic cognitive abilities. Several theoreticians have argued that everyday cognition measures are somewhat distinct from traditional cognitive assessment approaches, and the authors investigated this assertion correlationally in the present study. The sample consisted of 174 community-dwelling older adults from the Detroit metropolitan area, who had an average age of 73 years. Major results of the study showed that (a) each everyday cognitive test was strongly correlated with the basic cognitive abilities; (b) several basic abilities, as well as measures of domain-specific knowledge, predicted everyday cognitive performance; and (c) everyday and basic measures were similarly related to age. The results suggest that everyday cognition is not unrelated to traditional measures, nor is it less sensitive to age-related differences.     

Sensory processing, reading, IQ, and attention

Detection thresholds for two visual- and two auditory-processing tasks were obtained for 73 children and young adults who varied broadly in reading ability. A reading-disabled subgroup had significantly higher thresholds than a normal-reading subgroup for the auditory tasks only. When analyzed across the whole group, the auditory tasks and one of the visual tasks, coherent motion detection, were significantly related to word reading. These effects were largely independent of ADHD ratings; however, none of these measures accounted for significant variance in word reading after controlling for full-scale IQ. In contrast, phoneme awareness, rapid naming, and nonword repetition each explained substantial, significant word reading variance after controlling for IQ, suggesting more specific roles for these oral language skills in the development of word reading.     

Personality, intelligence, and spatial visualization: correlates of mental rotations test performance

In the context of a longitudinal study of cognitive and personality development, I examined various correlates of spatial visualization ability, as measured by Vandenberg's Mental Rotations Test, in order to elaborate the meaning of the known sex difference on this factor. Spatial visualization ability in females was correlated with verbal IQ and various aspects of personality. These relations were absent in males. Within each sex, measures of cognitive abilities obtained in childhood predicted spatial visualization ability at age 18. Hypotheses designed to explain the sex difference in spatial visualization must be sensitive to the different implications of this factor in males and females.     

小学儿童英语正字法技能的发展及其在单词阅读中的作用

为系统探讨正字法技能不同成分的发展特点及其在英语单词阅读中的作用,对小学一、三、五年级共110名儿童施测英语正字法规则意识、正字法模式建构技能、正字法编码技能、单词阅读以及一般认知能力和英语语音意识测验。结果表明：（1）汉语儿童的英语正字法技能各成分随年级显著增长,各成分间及其与一般认知技能、语音意识的关系存在年级差异;（2）控制年龄、一般认知能力和语音意识后,正字法技能在三、五年级仍对单词阅读有显著的独立解释作用,且其独立贡献率高于语音意识;（3）进一步控制其他正字法技能成分后,正字法规则意识以正字法模式建构技能为完全中介间接地作用于单词阅读,正字法模式建构技能在三、五年级都仍对单词阅读有显著的独立解释作用,正字法编码技能在五年级中能显著地独立解释单词阅读的部分变异。     

ROLE-TAKING AND REFERENTIAL COMMUNICATION ABILITIES IN FIRST- AND THIRD-GRADE CHILDREN1

This study investigated role-taking and referential communication abilities in children. The effects of age, sex, and IQ on both abilities were tested, and the effect of age of receiver on referential communication ability was also examined. Multiple regression analyses were utilized to determine how well the independent variables predict the measures of role-taking and referential communication. Finally, the relationship between role-taking and referential communication was assessed. The participants were 32 first-graders and 32 third-graders. At each grade level, there were equal numbers of boys and girls. Age was found to affect performance on role-taking and communication tasks. Both sex of the child and IQ were found to affect referential communication performance. The relationship between role-taking and referential communication abilities was low. Interpretation of significant results is given, and testing procedures are discussed.     

The link between logic,mathematics and imagination: evidence from children with developmental dyscalculia and mathematically gifted children

This study examined performance on transitive inference problems in children with developmental dyscalculia (DD), typically developing controls matched on IQ, working memory and reading skills, and in children with outstanding mathematical abilities. Whereas mainstream approaches currently consider DD as a domain‐specific deficit, we hypothesized that the development of mathematical skills is closely related to the development of logical abilities, a domain‐general skill. In particular, we expected a close link between mathematical skills and the ability to reason independently of one's beliefs. Our results showed that this was indeed the case, with children with DD performing more poorly than controls, and high maths ability children showing outstanding skills in logical reasoning about belief‐laden problems. Nevertheless, all groups performed poorly on structurally equivalent problems with belief‐neutral content. This is in line with suggestions that abstract reasoning skills (i.e. the ability to reason about content without real‐life referents) develops later than the ability to reason about belief‐inconsistent fantasy content.A video abstract of this article can be viewed at http://www.youtube.com/watch?v=90DWY3O4xx8     

Assessment of working memory components at 6years of age as predictors of reading achievements a year later

The ability of working memory skills (measured by tasks assessing all four working memory components), IQ, language, phonological awareness, literacy, rapid naming, and speed of processing at 6 years of age, before reading was taught, to predict reading abilities (decoding, reading comprehension, and reading time) a year later was examined in 97 children. Among all working memory components, phonological complex memory contributed most to predicting all three reading abilities. A capacity measure of phonological complex memory, based on passing a minimum threshold in those tasks, contributed to the explained variance of decoding and reading comprehension. Findings suggest that a minimal ability of phonological complex memory is necessary for children to attain a normal reading level. Adding assessment of phonological complex memory, before formal teaching of reading begins, to more common measures might better estimate children’s likelihood of future academic success.     

Temporal processing ability in above average and average readers

In the present study, we compared the rapid visual and auditory temporal processing ability of above average and average readers. One hundred five undergraduates participated in various visual and auditory temporal tasks. The above average readers exhibited lower auditory and visual temporal resolution thresholds than did the average readers, but only the differences in the auditory tasks were statistically significant, especially when nonverbal IQ was controlled for. Furthermore, both the correlation and stepwise multiple regression analyses revealed a relationship between the auditory measures and the wide range achievement test (WRAT) reading measure and a relationship between the auditory measures and a low spatial frequency visual measure and the WRAT spelling measure. Discriminant analysis showed that together both the visual and auditory measures correctly classified 75% of the subjects into above average and average reading groups, respectively. The results suggest that differences in temporal processing ability in relation to differences in reading proficiency are not confined to the comparison between poor and normal readers.