Correlates of Academic Overachievement,Nondiscrepant Achievement,and Learning Disability in ADHD,Autism, and General Population Samples

ABSTRACT

Little is known about the characteristics of academic overachievers, children whose achievement significantly exceeds IQ. Correlates of overachievement (achievement test scores ≥ 1 SD above IQ), nondiscrepant achievement, and learning disability (LD; achievement ≥ 1 SD below IQ) were analyzed in 1,543 children (739 ADHD, 285 autism, and 519 general population), 6–16 years of age. Significant correlates of the reading and math achievement groups were diagnosis (autism greatest overachievement, ADHD greatest LD), IQ (lowest in overachievers and highest in LD), and Working Memory scores relative to the child’s IQ (close to or exceeding IQ in overachievers and lower than IQ in LD). Demographics (age, sex, race, and parent occupation) and parent and teacher ratings of psychopathology (e.g., behavior problems, anxiety, and depression) and personality characteristics (e.g., motivation and self-confidence) did not contribute significantly more to predicting overachievement and LD beyond that explained by IQ, diagnosis, and working memory. These findings suggest an underlying neurobiological etiology for both overachievement and LD.     

WISC-R verbal and performance abilities of native american students referred for school learning problems

This study was designed to determine if three diagnostic groups of Navajo children differed on intellectual dimensions as measured by the WISC-R. Subjects had been previously diagnosed by state certified professionals and were identified as nonhan dicapped (NH) (N = 113), educationally disadvantaged.(ED) (N = 189), and learning disabled (LD) (N = 150). NH group means on all WISC-R variables were significantly higher than the LD group means. The ED and the LD group means were similar on the verbal measures, but the LD group scores were lower than the ED group scores on performance measures. The NH group demonstrated intellectual abilities and deficits similar to those reported for other primary-grade Navajo children who had not been referred for suspected handicapping conditions.     

The impact of the Flynn effect on LD diagnoses in special education

Because of the Flynn effect, IQ scores rise as a test norm ages but drop on the introduction of a newly revised test norm. The purpose of the current study was to determine the impact of the Flynn effect on learning disability (LD) diagnoses, the most prevalent special education diagnosis in the United States. Using a longitudinal sample of 875 school children who were initially diagnosed with LD on the Wechsler Intelligence Scale for Children-Revised (WISC-R), children experienced a significant decline in IQ when retested on the third edition of the WISC (WISC-III) compared to peers who were tested on the WISC-R twice. Furthermore, results from logistic regression analyses revealed that the probability of a rediagnosis of LD on reevaluation significantly decreased, in part, because of this decline on the WISC-III. These results are discussed in terms of their implications for both basic research and educational policy.     

An operational definition of learning disabilities (cognitive domain) using WISC full scale IQ and peabody individual achievement test scores

An operational index of discrepancy to assist in identifying learning disabilities (LD) in the cognitive domain was derived using the Full Scale IQ, Wechsler Intelligence Scale for Children (Wechsler, 1949, and relevant subtest scores on the Peabody Individual Achievement Test (PIAT) (Dunn and Markwardt, 1970. The index was applied to all legally identified LD children (N = 60) of a Michigan county who were in the LD program (1% of the total elementary school population of 6000 children). Of the 50 males and 10 females (mean age: 9 years 2 months; mean IQ: 91), the index identified 74% and 30% respectively as may be LD in the cognitive domain. This comprised 67% of the 60 children, or 2/3 of 1 % of the total elementary school population. Of the 67% may be LD children, 93% had discrepancy low PIAT subtest scores in Reading Recognition, 88% in Reading Comprehension, 83% in Spelling, and 52% in Arithmetic. Considerable caution should be exercised when classifying children, especially females, as LD.     

Subtest scatter and Kaufman regroupings on the WISC-R in non-learning-disabled and learning-disabled children

The present study was undertaken to examine scatter analysis and Kaufman regroupings of WISC-R scores. Thirty-one non-learning-disabled children (NLD) and 29 learning-disabled children (LD) determined by individual IQ and achievement scores served as subjects. Scatter indices were computed within the Verbal and Performance subtests as well as between the Verbal and Performance IQ scales. Also, the regrouping categories proposed by Kaufman (1979) were examined. A significant difference in Verbal and Performance IQs was found between the LD and NLD group. Significantly more students in the LD group exhibited the Kaufman regrouping pattern than in the NLD group (p < .01). These results suggest that Kaufman regroupings and Verbal-Performance scatter analysis may be used to assist in diagnosing LD children.     

Cognitive functioning as measured by the WISC-R: do children with learning disabilities have distinctive patterns of performance?

Patterns of performance on the Wechsler Intelligence Scale for Children-Revised (WISC-R) have been proposed as useful tools for the identification of children with learning disabilities (LD). However, most of the studies of WISC-R patterns in children with LD have been plagued by the lack of a typically achieving comparison group, by failure to measure individual patterns, and by the lack of a precise definition of LD. In an attempt to address these flaws and to assess the presence of patterns of performance on the WISC-R, we examined data from 121 children with typical achievement (TA), 143 children with reading disabilities (RD), and 100 children with a specific arithmetic disability (AD), ages 6 to 16 years. The results indicated that the RD and AD groups had significantly lower scores than the TA group on all the Verbal IQ subtests. Many of the children with AD and RD showed a significant difference between Verbal and Performance IQ scores, but so did many of the typically achieving children. Although there were some children with LD who showed the predicted patterns, typically, 65% or more of the children with LD did not. Furthermore, a proportion of the TA group-generally not significantly smaller than that of the RD and AD groups-showed discrepancy patterns as well. Our results indicate that the patterns of performance on intelligence tests are not reliable enough for the diagnosis of LD in individual children. Therefore, it might be more profitable to base the detection of an individual's LD on patterns of achievement test scores.     

A short-form version of the WISC-R for the learning disabled

This study investigated the best short form version of the WISC-R for learning disabled (LD) students. The WISC-R was administered to 234 LD and 290 children who were referred for psychological evaluation but were found not eligible (NE) for special education services from 45 school districts in Michigan. Stepwise multiple regressions were calculated to ascertain the best tetrads of Full Scale IQ (FS IQ) for the two groups. For the NE sample, Vocabulary, Picture Arrangement, Picture Completion, and Information were the best four indicators of FS IQ, accounting for about 80% of the variance in Full Scale scores. For the LD sample, the best four predictors of FS IQ were Similarities, Block Design, Picture Completion, and Vocabulary, accounting for about 80% of criterion variance. Using the WISC-R standardization data, Sattler identified the Information, Vocabulary, Comprehension, and Block Design subtests as one of the best short form versions for predicting FS IQ. For the LD sample of the present study, Sattler's composite yielded a multiple R of .873 with FS IQ, whereas our best four predictors yielded a multiple R of .896. It appears that Sattler's tetrad is about as good a predictor of FS IQ for LD students as that found in the present data.     

The stability of child study team classification over four years

Forty-nine learning disabled (LD), 30 emotionally disturbed(ED), and 44 unclassified (UC) boys originally sampled by Brooks (Note 1) and Jackson (Note 4) when they were 6 to 11 years of age, were relocated in 1979, and their current classification determined. Lambda, an index of predictive association, showed that a 53% improvement in the accuracy of prediction of 1979 classification was obtained when 1975 classification was given. The ED classification was the least stable, with 60% of the children originally classified ED changing their classification over four years, though only 19% of the originally LD and ED children were unclassified four years later.     

Language problems in children with learning disabilities: do they interfere with maternal communication?

In this study, parent-child interaction in two carefully matched subgroups-school-age boys with learning disabilities (LD) who showed a discrepancy between their verbal IQ and performance IQ and had more extensive difficulties in higher-level language abilities (VIQ < PIQ, n = 8) and boys with LD who did not manifest a discrepancy between verbal IQ and performance IQ (VIQ = PIQ, n = 8), were investigated. The effects of the child's language problems on child task performance and on the quality of maternal communication were analyzed in a mother-child problem solving task. Children in the VIQ < PIQ group were found to be less successful on the task than children in the VIQ = PIQ group, and their mothers exhibited lower communication clarity in their instructions than the mothers of the children in the VIQ = PIQ group. An interesting interaction effect was found for communication deviances. For mothers in the VIQ < PIQ group the extent of deficient communication increased from the monologue to the dialogue situation, whereas communication deviances decreased for mothers in the VIQ = PIQ group. Three possible models are discussed in light of the differences between the subgroups.     

Diagnostic utility of the number of Wisc‐III subtests deviating from mean performance among students with learning disabilities

This paper examined the diagnostic utility of subtest variability, as represented by the number of subtests that deviate from examinees' mean IQ scores, for identifying students with a learning disability (LD). Participants consisted of the 2,200 students in the WISC‐III normative sample and 684 students (Mdngrade = 5; Mage = 10.8) identified as LD. The number of subtests deviating from examinees' Verbal, Performance, and Full Scale IQ by ±3 points for normative and exceptional samples were contrasted via Receiver Operating Curve (ROC) analyses. Results indicated that LD students did not differ from normative sample children at levels above chance. It was concluded that deviation of individual subtest scores from mean IQ scores has no diagnostic utility for hypothesizing about students with learning disabilities. © 2000 John Wiley & Sons, Inc.     

Academic underachievement among children with epilepsy: proportion exceeding psychometric criteria for learning disability and associated risk factors

This study assessed rates of learning disabilities (LD) by several psychometric definitions in children with epilepsy and identified risk factors. Participants (N = 173, ages 8-15 years) completed IQ screening, academic achievement testing, and structured interviews. Children with significant head injury, chronic physical conditions, or mental retardation were excluded. Using an IQ-achievement discrepancy definition, 48% exceeded the cutoff for LD in at least one academic area; using low-achievement definitions, 41% to 62% exceeded cutoffs in at least one academic area. Younger children with generalized nonabsence seizures were at increased risk for math LD using the IQ-achievement discrepancy definition; age of seizure onset and attention-deficit/hyperactivity disorder (ADHD) were risk factors for reading and math LD using low-achievement definitions. Writing was the most common domain affected, but neither ADHD nor seizure variables reliably identified children at risk for writing LD. Although children with earlier seizure onset, generalized nonabsence seizures, and comorbid ADHD appear to be at increased risk for some types of LD by some definitions, these findings largely suggest that all children with epilepsy should be considered vulnerable to LD. A diagnosis of epilepsy (even with controlled seizures and less severe seizure types) should provide sufficient cause to screen school-age children for LD and comorbid ADHD.     

Learning disabilities in children with very low birthweight: prevalence, neuropsychological correlates, and educational interventions

This study examined achievement, neuropsychological, and intervention outcomes at a mean age of 11 years in children with very low birthweight (VLBW, <1500 g) compared with a term-born control group. To assess the prevalence and correlates of specific learning disabilities (LD), the sample was limited to children without neurosensory disorders who had at least low average IQ. Participants included 31 children with <750 g birthweight, 41 with 750-1499 g birthweight, and 52 controls. The <750 g group obtained lower scores in math, IQ, and perceptual-organizational skills than the term-born group. The < 750 g group also had higher rates of past and present LD than the controls. Despite these differences, the groups did not differ significantly in rates of special education or tutorial/remedial assistance. These findings suggest that children with extremely low birthweight without gross physical or intellectual impairments are at higher risk for LD and cognitive deficiencies than their term-born peers and that further efforts are needed to improve identification and treatment of these learning problems.     

Self-concept and IQ as predictors of remedial success in children with learning disabilities

Twenty-five children with learning disabilities (LD) in the auditory-linguistic realm participated in the present study over two academic years. The purpose of the experiment was to test whether IQ and self-concept were significant predictors of learning ability. IQ was found to have no relationship to the children's learning ability, whereas self-concept predicted patterns of successful achievement in spelling, arithmetic, and written language, but not in visual word recognition. The results were interpreted as support for the "specificity" presumption in LD, but also as support for the importance of self-concept as possibly a primary cause of academic underachievement. The paper develops a remedial model of LD that accounts both for the interplay of self-concept and cognition in learning and for the fundamental implications of the specificity principle.     

Stability of WISC-R subtest profiles for learning disabled children

Stability of the WISC-R subtest profile for 161 learning disabled (LD) children over a 7-month test-retest interval was examined. A unique subtest profile reported earlier (Smith, Coleman, Dokecki, & Davis, 1977a) was replicated. Performance IQ was significantly greater than Verbal IQ at both testing occasions. A mean test-retest increase was observed for Performance IQ, but not for Verbal IQ.     

Grade retention among students with learning disabilities

This study explored the rates of grade retention among children with undiagnosed learning disabilities. During the 1990–91 school year, data were collected on 344 Michigan students who were referred for special-education evaluation due to learning problems. Of the 201 students determined to possess a learning disability (LD), 71.6% had been retained at least once before they were referred for special-education evaluation. Minority and urban LD students were more apt to be retained before being referred for evaluation. Retained LD students were usually one year older than nonretained LD students at the time of special-education referral. Although retention among LD students did not appear to be related to gender or grade placement, retained LD students generally exhibited lower levels of intelligence and weaker skills in reading comprehension, writing, and math at the time of their referral. © 1996 John Wiley & Sons, Inc.     

Maternal stress in nonverbal learning disorder: a comparison with reading disorder

Maternal stress was assessed in mothers of children ages 8 to 11 years with learning disorders (LD). Age-, gender-, and IQ-matched children with reading disorders (RD; n = 31), children with nonverbal learning disorders (NVLD; n = 21), and typically developing control participants (n = 23) participated. Mothers of children with LD reported higher levels of stress, although the specific nature of the stress appeared to vary by disorder subtype: Mothers of children with RD reported higher levels of general distress, whereas mothers of children with NVLD reported higher levels of dysfunctional interactions with their child. The severity of the LD was strongly associated with maternal stress in the sample of children with NVLD but not in the sample of children with RD. In the sample of children with NVLD, the best predictors of maternal stress were 2 variables associated with the child: The lower the child's Performance IQ, the higher the level of maternal stress. Furthermore, the level of the child's internalizing symptoms was also a strong predictor of maternal stress in the sample of children with NVLD. In our sample of children with RD, the 3 best predictors were all variables associated with the mother, including her age, her level of reported psychiatric symptoms, and her overall level of social support.     

Substance use, substance abuse, and LD among adolescents with a childhood history of ADHD

A clinic-referred sample of 109 children with attention-deficit/hyperactivity disorder (ADHD) was followed into adolescence for the ascertainment of alcohol and other drug use and abuse. Learning disability (reading or math) in childhood was examined as a predictor of adolescent substance use and substance use disorder for alcohol and marijuana. No statistically significant group differences for children with LD versus those without LD emerged even after using different methods to compute LD. IQ/achievement discrepancy scores were similarly not predictive of later use or abuse. However, children with ADHD who had higher IQs and higher levels of academic achievement in childhood were more likely to try cigarettes, to smoke daily, and to have their first drink of alcohol or first cigarette at an early age. Children with ADHD who had higher reading achievement scores were less likely to have later alcohol use disorder. Although these findings are necessarily preliminary, due to the small number of children interviewed, the pattern of results suggests that level of cognitive functioning--rather than discrepancy between IQ and achievement--is important for the prediction of later substance use and abuse, at least in this clinic-referred sample of children with ADHD. Further, different mechanisms of risk related to cognitive functioning may be operating for experimentation with legal drugs such as alcohol and tobacco, regular cigarette smoking, and problematic alcohol use.     

The boder test: Neuropsychological and demographic features of dyslexic subtypes

The Boder Test may represent a viable screening instrument for the identification of dyslexia and dyslexic subtypes. Proportions of the 30 LD children studied identified by Boder's classification system as dysphonetic (63.3%), dyseidetic (6.7%), and mixed dysphonetic-dyseidetic (13.3%) were similar to those reported in earlier studies. Neuropsychological characteristics associated with the Boder categories were consistent with the literature: Significantly fewer dysphonetic readers were represented in the V > and Spatial<Sequential IQ groups, and left-handedness and left-hand tapping preference were overrepresented in the mixed dyslexic category. Black children who had been identified as learning disabled on the basis of other tests were categorized as normal readers by the Boder, suggesting its possible use as a nonbiased measure of reading.     

WISC-R patterns for learning disabled children at three SES levels

WISC-R and socioeconomic status (SES) data were collected on 122 learning disabled (LD) children who had been assigned to self-contained LD classrooms. The children were divided into three groups on the basis of family SES: high, middle, and low. Three questions were explored: (a) Is there a relationship between SES and IQ test scores among LD-labeled children? (b) Is the pattern of subtest scores independent of SES level? (c) Is the Verbal-Performance IQ test score discrepancy independent of SES level? Results supported affirmative answers to all three questions. Discussion centered around the implications of these results for future research on the utility of the WISC-R for diagnostic purposes.     

Predicting delay in reading achievement in a highly transparent language

A random sample of 91 preschool children was assessed prior to receiving formal reading instruction. Verbal and nonverbal measures were used as predictors for the time of instruction required to accurately decode pseudowords in the highly orthographically regular Finnish language. After 2 years, participants were divided into four groups depending on the duration of instruction they had required to reach 90 % accuracy in their reading of pseudowords. Participants were classified as precocious decoders (PD), who could read at school entry; early decoders (ED), who learned to read within the first 4 months of Grade 1; ordinary decoders (OD), who learned to read within 9 months; and late decoders (LD), who failed to reach the criterion after 18 months of reading instruction at Grade 2. Phonological awareness played a significant role only in differentiating PD from ED and OD. However, phonological awareness failed to predict the delayed learning process of LD. LD differed from all other groups in visual analogical reasoning in an analysis not containing phonological awareness measures. Letter knowledge and visual analogical reasoning explained above 90% of the PD-LD difference. Preschool composite (objects, colors, and digits) naming speed measures best predicted reading fluency at the end of Grade 2. The supportive role of orthographic knowledge in phonological awareness, the role of visual analogical reasoning, and the inability of phonological measures to discriminate late decoders are discussed.