A study of IQ in Lithuania

Data for the Colored Progressive Matrices were collected for a sample of 259 8- to 12-yr.-old children in Lithuania in 1999. In relation to the British 1979 standardization sample the mean IQ of the Lithuanian children was 92.2. Adjusted for the estimated secular increase of intelligence in Britain, the Lithuanian mean IQ is estimated at 90.     

Recent data for majority and racial minority differences in intelligence of 5 year olds in the United Kingdom

Data are presented from the UK Millennium Cohort Study for a sample of 14,860 5 year old British children giving the IQs of whites and racial minorities. Africans, Indians, Pakistanis and Bangladeshis obtained lower IQs than whites, while the IQ of the Chinese was higher. These group differences in IQ were consistent with the differences in educational attainments and earnings.     

A study of the performance of Egyptian college students on the Advanced Progressive Matrices

Results are reported for intelligence assessed with the Advanced Progressive Matrices of a sample of students at Ain-Shams University in Cairo (N = 2147). The Egyptian raw scores were transformed to British IQ equivalents using the published 1992 British norms for the APM, on which the sample obtained a British IQ of 89.5. Science students obtained a significantly higher average mean score than arts students by 7.5 IQ points. Male students obtained a non-significantly higher average IQ than female students 1.2 IQ points. Male students had greater variability than the female students.     

A new estimate of the IQ in Estonia

The Standard Progressive Matrices was standardized in Estonia in 2001 on a sample of 1,835 7- to 11-yr.-olds. The mean IQ of the Estonian sample was estimated at 98 in relation to a British IQ of 100 and 99 based on the combined results for two studies.     

Sex Differences in Parental Estimates of Their Children's Intelligence

A series of previous studies with studentparticipants has shown that females' self-IQ estimatesare significantly lower than those of males. In thisstudy, 184 mostly white British adults estimated their own IQ and that of their children. The resultswere in line with previous studies, in that males ratedtheir IQ higher than females (108 vs. 104). Both sexesrated their male children higher than their female children (109 vs. 102). Males tendedmore than females to believe there is a greaterdifference between the intelligence of female and malechildren, but this was not significant. Results wereconsidered in terms of the current sociobiological andsociocultural explanations for sex differences inability.     

Do the Wechsler scales underestimate the difference between verbal and performance abilities in children with language–related disorders?

The present paper examines the validity of the Wechsler scales with children with language-related disorders, with whom the scales were not originally normed. The general question is whether we can take measures of IQ, normed with a normal sample, and then validly use them as indicators of the same constructs with samples significantly different from the normed sample. In previous papers it was pointed out that the pattern structurally simple > moderately complex > complex tests can be observed in their IQ profiles within both the Verbal scale and the Performance scale. In this paper, it is hypothesized that this scatter of scores leads to an underestimation of the global V-P IQ differences for children with language-related disorders because there are more structurally complex tests on the Performance scale than on the Verbal scale. To test this hypothesis, "purer" V-P IQ differences were calculated by comparing the scores on Verbal and Performance tests of equal structural complexity. WPPSI and WISC-R data from four groups of children were analyzed: language-impaired children (n = 128), reading-impaired children (n = 112), children from dyslexic families (n = 51), and normal children (n = 49). When the effect of the difference in structural complexity was controlled for, it was found that the distribution of the revised V-P IQ difference was significantly more toward the negative end of the spectrum than the traditional V-P IQ differences for language-impaired and reading-impaired children, and approaching a significant level for children from dyslexic families. As hypothesized, there were no significant differences between the two distributions of V-P IQ differences for normal children. Practical and theoretical implications are discussed.     

Parents think their sons are brighter than their daughters: sex differences in parental self-estimations and estimations of their children's multiple intelligences

In this study, 156 participants, predominantly White British adults (M age = 44.3 years) rated themselves on overall IQ and on H. Gardner's (1983) 7 intelligence subtypes. Parents (n = 120) also estimated the intelligence of their children. Men's self-estimates were significantly higher than women's (110.15 vs. 104.84). Participants thought their verbal, mathematical, and spatial intelligence scores were the best indicators of their own overall intelligence. Parents estimated that their sons had significantly higher IQs than their daughters (115.21 vs. 107.49). Self-estimates and estimates of children's multiple intelligences were higher for men and sons, significantly so for logical-mathematical and spatial intelligence. Parents rated 2nd-born daughters as having significantly higher verbal and musical intelligence than their male counterparts. Higher parental IQ self-estimates corresponded with higher IQ estimates for children. Results for 1st-born children were clearest and showed the most significant differences. The findings are interpreted in terms of sociocultural and familial influences and the possibility of actual sex differences in particular abilities.     

Intelligence,gender, and assessment method affect the accuracy of self‐estimated intelligence

Self‐estimates of intelligence (SEI), which influence to what extent people engage in and how well they perform at a task, are subject to distortion. Here, the distortion effects of individual differences in intelligence (IQ), gender, and proximal (with reference to test performance) and distal (with reference to IQ score distributions) assessments of SEI were tested in a sample of 200 British adults. The results showed that (1) people with lower IQ misestimated their SEI to a greater extent than people with high IQ; (2) this effect was more pronounced in distal than proximal measures of SEI; (3) SEI means did not differ significantly across gender but the IQ‐related level of SEI distortion did; (4) this effect was greater for distal than proximal measurement; and (5) proximal SEI were on average less distorted than distal SEI scores and also correlated more closely with IQ. Overall, the findings suggest that the distal SEI assessment method resulted in greater gender‐ and IQ‐related distortions of SEI.     

Chinese sex differences in intelligence: Some new evidence

Sex differences on the WISC-R in Chinese children were examined in a sample of 788 aged 12 years. Boys obtained a higher mean full scale IQ than girls of 3.75 IQ points, a higher performance IQ of 4.20 IQ points, and a higher verbal IQ of 2.40 IQ points. Boys obtained significantly higher means on the information, picture arrangement, picture completion, block design, and object assembly subtests, while girls obtained a significantly higher mean on coding. The results were in general similar to the sex differences in the United States standardisation sample of the WISC-R. Boys showed greater variability than girls.     

Intelligence Measurement by Computerized Information Processing using Inspection Time

A computer program was used to investigate the correlation of IQ with inspection time (IT). The program was written as a space game and was presented to 122 fourth-, fifth-, and sixth-grade children. The results were then compared to known Otis-Lennon IQ scores. The correlation was moderately high (.79), most subjects scoring within one stanine of the Otis IQ. Not included in the correlation sample were 23 children of the same grade and age level who were classified by school officials as having reading and language difficulties. All of these children scored significantly higher in IT and teacher evaluation than they did on the SAT vocabulary test and the Otis IQ. IT is a useful alternative to the more traditional measures of IQ. In addition, the computerized approach used in this study overcame many of its criticisms.     

The determinants of parents' beliefs about the intelligence their children: A study from Hong Kong

One hundred and ninety‐three Hong Kong parents (mean age 42.2 years) were given a structured interview / questionnaire concerning their own and their children's self‐estimated overall and multiple intelligence. Previous research suggested that males tend to give higher overall “g” estimates to their children and themselves than do females, as well as higher scores on mathematical and spatial intelligence (Furnham, 2001). Further, studies in the West suggest that parents think their children are significantly brighter than they are and that their sons are brighter than their daughters. Estimates were lower than those found in Western populations but, even so, males rated their own mathematical and spatial intelligence higher than did females. Hong Kong Chinese parents did not think their sons were brighter than their daughters. The seven multiple intelligences factored into three clear factors for self and children, and regressions indicated that it was “academic” intelligence (verbal, mathematical, spatial) that was most “g” loaded. The child's age and the self‐rated overall IQ of both the parents were the best predictors of the child's overall estimated IQ. Less than a third of the parents had taken an IQ test or believed they measured IQ very well. Those who were more likely to be better educated, had taken an IQ test, and believed intelligence was inherited were more likely to award themselves higher overall IQ scores. Results are compared with the British studies in the same area.     

III. WISC-R scatter indices: Useful information for differential diagnosis?

This study analyzed the WISC-R verbal-performance, full scale IQ, verbal IQ, and performance IQ scatter indices of 101 verified special education students. The results indicated that none of these measures discriminated among emotionally disturbed, learning disabled, minimally brain injured, and educable mentally retarded children. These scatter indices were also compared with analogous data collected from a nationwide, representative sample of normal children (Kaufman, 1976a, 1976b). Statistically significant differences were obtained between the two groups on verbal-performance, full scale IQ, and performance IQ scatter dimensions. Further analyses revealed, however, that 40% of the normal children exhibited as much or more scatter than the average special education student on each of these three scatter indices. There were no significant differences between the two groups on the verbal IQ scatter index. The results are discussed in terms of the limited utility of WISC-R scatter indices for the purpose of differential diagnosis.     

Assessment of preschoolers at-risk with the WPPSI--R and the Stanford-Binet L-M.

The purpose of this study was to provide data on the validity of using the WPPSI--R with 16 preschoolers who had been referred for psychological assessment. A comparison of the preschoolers' performance on the WPPSI--R and the Stanford-Binet L-M was made. Children ranged in age from 3-0 to 6-0 years, with a mean age of 4-5 yr. The correlations between WPPSI--R and Stanford-Binet L-M scores were strong; WPPSI--R Verbal IQ and Stanford-Binet L-M IQ, r = .85; WPPSI--R Performance IQ and Stanford-Binet L-M IQ, r = .75, and WPPSI--R Full Scale IQ and Stanford-Binet L-M IQ, r = .82. For this very small sample of children whose mean IQ was significantly below average, the WPPSI--R appeared to assess validly their current intellectual functioning. Attention should be given concurrent and predictive validity as well as the efficiency of using the WPPSI--R with other and larger samples of referred children.     

Are apparent sex differences in mean IQ scores created in part by sample restriction and increased male variance?

This study investigated the possibility that apparent sex differences in IQ are at least partly created by the degree of sample restriction from the baseline population. We used a nationally representative sample, the 1970 British Cohort Study. Sample sizes varied from 6518 to 11,389 between data-collection sweeps. Principal components analysis of scores obtained on four cognitive tests administered at age 10 was used to obtain estimates that we name ‘IQ’. These age-10 scores were then used to estimate the sex differences at age 10, and also among participants in the two later waves, at age 26 and 30. At age 10, there was a small but significant advantage for boys (Cohen’s d = 0.081). Boys had greater variability in these IQ scores. We then investigated how this very small male advantage at 10 changed with sample restriction. We used the same IQs obtained at age 10, but considered only those subjects who returned for data-collection sweeps at ages 26 and 30 years. Subjects returning at age 26 and 30 were more likely to be females and to have higher age-10 IQ scores. Attrition at age 30 was 28% and the male advantage in IQ scores increased by 15%. Attrition at age 26 was 43% and the male advantage in IQ scores increased by 48%. The findings underline the importance of monitoring attrition in longitudinal studies, as well as emphasising the need for representative samples in studying sex differences in intelligence. A proportion of the apparent male advantage in general cognitive ability that has been reported by some researchers might be attributable to the combination of greater male variance in general cognitive ability and sample restriction, though this remains to be tested in a sample with an appropriate mental test battery.     

Parents' reactions to finding out that their children have average or above average IQ scores

The parents of 41 children who had been given an individually-administered intelligence test were contacted approximately 19 months after testing. The sample included 20 parents who had learned their child had an Average IQ (children'smeanIQ = 100.8) and 21 parents who had learned their child had an Above Average IQ (children'smeanIQ = 130.0). Parents of Average IQ children were less accurate in their memory of test results, and they and their children experienced fewer positive consequences from IQ testing than Above Average children and their parents. Children with Above Average IQ experienced extremely low frequencies of sibling rivalry, conceit or pressure, and they and their parents experienced increased pride and/or self-confidence as a result of the IQ testing. The results as a whole suggest that parents of Average IQ children may need more psychological support during the parent informing process than parents of Above Average IQ children.     

IQ correlations in transracial adoptive families

IQ tests were administered to all available members over 4 years old in 101 transracial adoptive families when the adopted children were an average of 7 years old and again when they averaged 17 years old. At both times, 426 members of 93 families were studied; 398 were seen in person and administered the WAIS-R or WISC-R. IQ correlations were calculated for adopted and biological parent-child pairs, and for genetically related and unrelated siblings. Educational levels of birth parents were correlated with the IQ scores of their adopted-away children. Results show that biologically related family members tended to resemble each other intellectually more than did adoptive family members at both time points. IQ correlations for biological parent-child pairs exceeded those for adoptive parent-child pairs, and correlations were greater for genetically related than unrelated siblings. In late adolescence, the IQ scores of unrelated siblings in the transracial adoptive families were more similar than those of unrelated adolescent siblings pairs reported in other studies. The pattern of IQ correlations for unrelated siblings suggested that familial environmental influences on IQ decline from childhood to late adolescence, but this conclusion was not supported by parent-child IQ correlations. The effects of selective placement on familial IQ correlations were small. Estimates of genetic and familial environmental influences on IQ were very similar to those of other studies. This suggests that the influences on intellectual development in this sample of black/interracial adoptees reared in white families are similar to those for children in the majority populations of the United States and Western Europe.     

Parents Think Their Sons Are Brighter Than Their Daughters: Sex Differences in Parental Self-Estimations and Estimations of Their Children's Multiple Intelligences

In this study, 156 participants, predominantly White British adults (M age = 44.3 years) rated themselves on overall IQ and on H. Gardner's (1983) 7 intelligence subtypes. Parents (n = 120) also estimated the intelligence of their children. Men's self-estimates were significantly higher than women's (110.15 vs. 104.84). Participants thought their verbal, mathematical, and spatial intelligence scores were the best indicators of their own overall intelligence. Parents estimated that their sons had significantly higher IQs than their daughters (115.21 vs. 107.49). Self-estimates and estimates of children's multiple intelligences were higher for men and sons, significantly so for logical-mathematical and spatial intelligence. Parents rated 2nd-born daughters as having significantly higher verbal and musical intelligence than their male counterparts. Higher parental IQ self-estimates corresponded with higher IQ estimates for children. Results for 1st-born children were clearest and showed the most significant differences. The findings are interpreted in terms of sociocultural and familial influences and the possibility of actual sex differences in particular abilities.     

Music lessons enhance IQ

The idea that music makes you smarter has received considerable attention from scholars and the media. The present report is the first to test this hypothesis directly with random assignment of a large sample of children (N = 144) to two different types of music lessons (keyboard or voice) or to control groups that received drama lessons or no lessons. IQ was measured before and after the lessons. Compared with children in the control groups, children in the music groups exhibited greater increases in full-scale IQ. The effect was relatively small, but it generalized across IQ subtests, index scores, and a standardized measure of academic achievement. Unexpectedly, children in the drama group exhibited substantial pre- to post-test improvements in adaptive social behavior that were not evident in the music groups.     

Working memory, reading, and mathematical skills in children with developmental coordination disorder

The aim of the present study was investigate the relationship between working memory and reading and mathematical skills in 55 children diagnosed with developmental coordination disorder (DCD). The findings indicate a pervasive memory deficit in all memory measures. In particular, deficits observed in visuospatial short-term and working memory tasks were significantly worse than in the verbal short-term memory ones. On the basis of these deficits, the sample was divided into high and low visuospatial memory ability groups. The low visuospatial memory group performed significantly worse on the attainment measures compared to the high visuospatial memory group, even when the contribution of IQ was taken into account. When the sample was divided into high and low verbal working memory ability groups, verbal working memory skills made a unique contribution to attainment only when verbal IQ was taken into account, but not when performance IQ was statistically controlled. It is possible that the processing demands of the working memory tasks together with the active motor component reflected in the visuospatial memory tasks and performance IQ subtest both play a crucial role in learning in children with DCD.     

First-grade predictors of mathematical learning disability: A latent class trajectory analysis

Kindergarten to third grade mathematics achievement scores from a prospective study of mathematical development (n = 306) were subjected to latent growth trajectory analyses. The four corresponding classes included children with mathematical learning disability (MLD, 6% of sample), and low (LA, 50%), typically (TA, 39%) and high (HA, 5%) achieving children. The groups were administered a battery of intelligence (IQ), working memory, and mathematical-cognition measures in first grade. The children with MLD had general deficits in working memory and IQ and potentially more specific deficits on measures of number sense. The LA children did not have working memory or IQ deficits but showed moderate deficits on these number sense measures and for addition fact retrieval. The distinguishing features of the HA children were a strong visuospatial working memory, a strong number sense, and frequent use of memory-based processes to solve addition problems. Implications for the early identification of children at risk for poor mathematics achievement are considered.