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Generational changes in IQ (the Flynn Effect) have been extensively researched and debated. Within the US, gains of 3 points per decade have been accepted as consistent across age and ability level, suggesting that tests with outdated norms yield spuriously high IQs. However, findings are generally based on small samples, have not been validated across ability levels, and conflict with reverse effects recently identified in Scandinavia and other countries. Using a well-validated measure of fluid intelligence, we investigated the Flynn Effect by comparing scores normed in 1989 and 2003, among a representative sample of American adolescents ages 13–18 (n=10,073). Additionally, we examined Flynn Effect variation by age, sex, ability level, parental age, and SES. Adjusted mean IQ differences per decade were calculated using generalized linear models. Overall the Flynn Effect was not significant; however, effects varied substantially by age and ability level. IQs increased 2.3 points at age 13 (95% CI=2.0, 2.7), but decreased 1.6 points at age 18 (95% CI=−2.1, −1.2). IQs decreased 4.9 points for those with IQ130 (95% CI=3.4, 3.6). The Flynn Effect was not meaningfully related to other background variables. Using the largest sample of US adolescent IQs to date, we demonstrate significant heterogeneity in fluid IQ changes over time. Reverse Flynn Effects at age 18 are consistent with previous data, and those with lower ability levels are exhibiting worsening IQ over time. Findings by age and ability level challenge generalizing IQ trends throughout the general population.

BackgroundMost research on the prevalence, distribution, and psychiatric comorbidity of intellectual disability (ID) relies on clinical samples, limiting the generalizability and utility of ID assessment in a legal context. This study assessed ID prevalence in a population-representative sample of US adolescents and examined associations of ID with socio-demographic factors and mental disorders.MethodsData were drawn from the National Comorbidity Survey Adolescent Supplement (N= 6256). ID was defined as: (1) IQ ⩽ 76, measured using the Kaufman Brief Intelligence Test; (2) an adaptive behavior score ⩽76, and (3) age of onset ⩽18 measured using a validated scale. The Composite International Diagnostic Interview assessed 15 lifetime mental disorders. The Sheehan disability scale assessed disorder severity. We used logistic regression models to estimate differences in lifetime disorders for adolescents with and without ID.ResultsID prevalence was 3.2%. Among adolescents with ID, 65.1% met lifetime criteria for a mental disorder. ID status was associated with specific phobia, agoraphobia, and bipolar disorder, but not behavior disorders after adjustment for socio-demographics. Adolescents with ID and mental disorders were significantly more likely to exhibit severe impairment than those without ID.ConclusionsThese findings highlight how sample selection and overlap between ID and psychopathology symptoms might bias understanding of the mental health consequences of ID. For example, associations between ID and behavior disorders widely reported in clinical samples were not observed in a population-representative sample after adjustment for socio-demographic confounders. Valid assessment and understanding of these constructs may prove influential in the legal system by influencing treatment referrals and capital punishment decisions.General Scientific SummaryCurrent definitions of intellectual disability (ID) are based on three criteria: formal designation of low intelligence through artificial problem-solving tasks, impairment in one's ability to function in his/her social environment, and early age of onset. In a national population sample of adolescents, the majority of those with ID met criteria for a lifetime mental disorder. Phobias and bipolar disorder, but not behavior disorders, were elevated in adolescents with ID. Findings highlight the need to consider how behavioral problems are conceptualized and classified in people with ID.

Many studies have shown inverse associations between childhood adversity and intelligence, although most are based on small clinical samples and fail to account for the effects of multiple co-occurring adversities. Using data from the 2001–2004 National Comorbidity Survey Adolescent Supplement, a cross-sectional US population study of adolescents aged 13–18 years (n = 10,073), we examined the associations between 11 childhood adversities and intelligence, using targeted maximum likelihood estimation. Targeted maximum likelihood estimation incorporates machine learning to identify the relationships between exposures and outcomes without overfitting, including interactions and nonlinearity. The nonverbal score from the Kaufman Brief Intelligence Test was used as a standardized measure of fluid reasoning. Childhood adversities were grouped into deprivation and threat types based on recent conceptual models. Adjusted marginal mean differences compared the mean intelligence score if all adolescents experienced each adversity to the mean in the absence of the adversity. The largest associations were observed for deprivation-type experiences, including poverty and low parental education, which were related to reduced intelligence. Although lower in magnitude, threat events related to intelligence included physical abuse and witnessing domestic violence. Violence prevention and poverty-reduction measures would likely improve childhood cognitive outcomes.

As with prisons, chemotherapy, and root canals, one cannot be wholeheartedly enthusiastic about intelligence tests. Even we who are strong advocates for intelligence testing can identify with the r...

Although word reading has traditionally been viewed as a foundational skill for development of reading fluency and comprehension, some children demonstrate “specific” reading comprehension problems, in the context of intact word reading. The purpose of this study was to identify specific patterns of errors associated with reading profiles—basic reading difficulties (BRD), reading fluency difficulties (RFD), reading comprehension difficulties (RCD), and typical readers (total n = 821). Results indicated significant differences between the groups on most error factors. Post hoc analyses indicated there were no significant differences between the RFD and RCD groups, but these groups demonstrated different patterns of significant weakness relative to typical readers. The RFD group was weaker in spelling and oral expression whereas the RCD group demonstrated difficulties in writing mechanics and listening comprehension. These findings indicate that comprehension deficits cannot be attributed only to fluency difficulties and that specific reading difficulties may translate to other aspects of achievement.

This study investigated the relationship between specific cognitive patterns of strengths and weaknesses (PSWs) and the errors children make in reading, writing, and spelling tests from the Kaufman Test of Educational Achievement–Third Edition (KTEA-3). Participants were selected from the KTEA-3 standardization sample based on five cognitive profiles: High Crystallized Ability paired with Low Processing Speed and Long-Term Retrieval (High Gc), Low Crystallized Ability paired with High Processing Speed and Long-Term Retrieval (High Gs/ Glr), Low Orthographic Processing (Low OP), Low Phonological Processing (Low PP), and Low Phonological Processing paired with Low Orthographic Processing (Low PP_OP). Error factor scores for all five groups were compared on Reading Comprehension and Written Expression; the first four groups were compared on Letter & Word Recognition, Nonsense Word Decoding, and Spelling, and the first three groups were compared on Phonological Processing. Significant differences were noted among the patterns of errors demonstrated by the five groups. Findings support the notion that students with diverse cognitive PSWs display different patterns of errors on tests of academic achievement.

We used contemporary psychometric theory of intelligence and confirmatory factor analysis to reanalyze data obtained on samples of nonhuman primates administered the Primate Cognition Test Battery. Our main goals were to interpret stability of the Primate Cognition Test Battery tasks and factors over time and to determine whether the cognitive factors that emerge from confirmatory factor analysis for apes can be interpreted from the perspective of a major theory of human intelligence, namely, the Cattell-Horn-Carroll model. We also analyzed data for 2½-year-old children on Wechsler's preschool test to afford a comparison between ape and child cognitive factors. Results indicated that multiple cognitive abilities provide the best factor solutions for both apes and children, and that the ape factors can be meaningfully interpreted from Cattell-Horn-Carroll theory. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Patterns of maintenance of ability across the life span have been documented on tests of knowledge ( Gc), as have patterns of steady decline on measures of reasoning ( Gf/Gv), working memory ( Gsm), and speed ( Gs). Whether these patterns occur at the same rate for adults from different educational backgrounds has been debated. In addition, age-related research is needed to study global IQs, especially in view of the increased reliance on IQ in capital punishment court cases. In this study, large representative samples of adults tested during the standardizations of three versions of the Wechsler Adult Intelligence Scale (WAIS) served as subjects: WAIS-R ( N = 1,480, ages 20-74), WAIS-III ( N = 2,093, ages 20-90), and WAIS-IV ( N = 1,800, ages 20-90). Based on regression analysis, patterns of aging on Full Scale IQ (FSIQ) and the four abilities (a) were essentially the same for males versus females and (b) characterized all levels of education across three generations of Wechsler’s adult scales.

In order to create fairer measures for the assessment of ethnic minority group children, the test authors of the Kaufman Assessment Battery for Children–Second Edition (KABC-II) created three different global indexes: the comprehensive Fluid-Crystallized Index (FCI); the Mental Processing Index (MPI), which excludes subtests that assess crystallized knowledge; and the Nonverbal Index (NVI), which excludes any subtest that requires verbal expression. The test authors encourage clinicians to use the MPI for children with cultural differences and the NVI for children with language differences. The implication is that the FCI is more biased than the MPI and NVI for assessing children from ethnic minorities. However, there has been no empirical evidence to support that hypothesis. Using structural equation modeling, we investigated the predictive validity of the three KABC-II global scores in predicting reading, writing, and math in a nationally representative sample of Caucasian, African-American, and Hispanic school-aged children across three grade groups (1–4, N = 724; 5–8, N = 743; and 9–12, N = 534). Contrary to the test authors’ predictions, the FCI emerged as the fairest predictor of achievement across all age and grade groups. Alternatively, the MPI and NVI showed a persistent intercept overprediction of African-American and Hispanic students’ achievements across grades 5–8. The results provide evidence that more comprehensive global scaled scores might, in fact, be fairer predictor variables than less culturally and linguistically influenced indexes when predicting the achievement of children and adolescents from ethnic minorities.

In this commentary, both father and son respond to the target article (Richardson and Norgate, this issue) from different perspectives. The son, a creativity researcher, generally echoes Richardson and Norgate's arguments, arguing for the construct of creativity to be considered as a supplement to IQ tests for predicting work success. The father, an IQ test developer, is more critical of some of Richardson and Norgate's conclusions and points to gaps in their overview.

The gender similarities hypothesis by J. S. Hyde ( 2005 ), based on large-scale reviews of studies, concludes that boys and girls are more alike than different on most psychological variables, including academic skills such as reading and math (J. S. Hyde, 2005 ). Writing is an academic skill that may be an exception. The authors investigated gender differences in academic achievement using a large, nationally stratified sample of children and adolescents ranging from ages 7-19 years (N = 2,027). Achievement data were from the conormed sample for the Kaufman intelligence and achievement tests. Multiple-indicator, multiple-cause, and multigroup mean and covariance structure models were used to test for mean differences. Girls had higher latent reading ability and higher scores on a test of math computation, but the effect sizes were consistent with the gender similarities hypothesis. Conversely, girls scored higher on spelling and written expression, with effect sizes inconsistent with the gender similarities hypothesis. The findings remained the same after controlling for cognitive ability. Girls outperform boys on tasks of writing.

The purpose of this study was to investigate developmental gender differences in academic achievement areas, with the primary focus on writing, using the child and adolescent portion (ages 6-21 years) of the Kaufman Test of Educational AchievementSecond Edition, Brief Form, norming sample (N = 1,574). Path analytic models with gender, parent education, age, age(2), and gender-by-age moderation as predictors of reading, writing, and math were used to test for gender differences and for the influence of development on these differences. A small but consistent advantage was identified for females in reading. No gender differences were detected in math. The most important results of the present study pertain to a gender gap in writing in favor of females that increased as a function of age. Male students are at greater risk for writing failure than are females. (C) 2015 Wiley Periodicals, Inc.

This special issue focuses on an array of studies conducted using the Kaufman Test of Educational Achievement–Third Edition (KTEA-3) error analysis system. These studies, based on KTEA-3 standardization and validation data with normal and clinical samples, were conducted to provide greater understanding of the kinds of errors students make in reading, writing, math, and oral language. This introduction provides a brief history of the error analysis system and outlines the organization of the special issue, which features commentaries on the articles by experts in the field. The themes throughout the special issue are patterns of errors made by students and the educational implications of these patterns.

This chapter highlights the use of the Kaufman Assessment Battery for Children (KABC)–II with preschoolers and can be used to guide clinical assessment practice. It deals with a brief description of how to interpret the KABC–II, and the interpretive process is exemplified with a clinical case report of a 4-year-old assessed with the KABC–II. The chapter highlights the features of the KABC–II that are particularly useful for assessing preschoolers. A critical component of the KABC–II is measurement of high-level, complex intelligent behavior. The KABC–II was designed to attract the interest of preschoolers by using colorful and true-to-life materials. The attention span of a very young child can be notably short. In light of this, the KABC–II shows an awareness of developmental changes in attention span as children get older. One of the goals in developing the KABC–II was to strengthen the subtest floors for low functioning children..

The purpose of this study was to (a) identify the relationship between specific types of reading ability, different forms of learning, and long-term memory and retrieval (Glr); and then (b) to determine the degree to which self-assessed reading ability and a Glr measure could predict objective reading ability. College students were administered three different reading assessments from the Kaufman Test of Educational Achievement, Second Edition (KTEA-II): word reading, reading comprehension, and nonsense word decoding. They were also given two pairs of Glr subtests that consisted of immediate and delayed versions from the Kaufman Assessment Battery for Children, Second Edition (KABC-II). One set was embedded within context, whereas the other was not. Results showed that although overall reading ability and reading comprehension correlated the highest with Glr measures that were embedded in context, word reading, and nonsense word decoding were correlated the highest with delayed measures of Glr. Second, the self-assessment accounted for 23% of the variability in overall reading ability. Not only do these results show the strength of the relationship between Glr and reading, but also the ability to use these measures along with self-assessment to screen for reading disabilities.

The dramatic decrease in U.S. blood lead levels (BLLs) since the 1970s has been documented--however, the anticipated societal impact on intelligence quotient (IQ) has not. The objectives of this study were to determine whether mean IQs of American adults, adjusted for demographics, have increased in concert with society's decreasing BLL.Mean IQs of eight normal adult cohorts (N=800), tested individually in 2007 by trained clinicians, were compared using ANCOVA and correlation analysis. Cohorts ranged in mean societal BLLs from 4 1/2 μg/dL (born 1985-1987) to 19 μg/dL (born 1963-1972). IQs were adjusted for confounders-education, gender, ethnicity, region, urban status. To control for age, we analyzed IQ data for a second adult sample (N=800), tested in 1995-all born when BLLs were high (1951-1975, BLL ≥ 15 μg/dL).When controlling for education, gender, ethnicity, and region, the regression of IQs on BLLs was significant (r=-0.84, p0.01); the modeled change in BLLs from 20 to 4 μg/dL suggests predicted increases of 3.8 IQ points (95% CI, 1.4-6.2). Also controlling for urban status produced significance (r=-0.88, p0.01) with predicted increases of 5.2 points (95% CI, 2.4-8.0). Control analyses ruled out aging as a confounder.The dramatic societal decreases in BLLs in the U.S. since the 1970s were associated with a 4-5-point increase in the mean IQs of Americans. This effect is consistent with researchers' predictions; however, other variables (e.g., medical advances) may have contributed to the IQ gains.

The two featured articles and eight commentaries on the WISC-IV (Wechsler, 2003) and WAIS-IV (Wechsler, 2008) in this special issue of Journal of Psychoeducational Assessment are of exceptional quality. As a collective, this special issue greatly advances the field of cognitive assessment by intelligently synthesizing the best of methodology (confirmatory factor analysis) with the best of theory (Cattell–Horn–Carroll). The Weiss et al. articles represent sophisticated approaches to test validation and interpretation and the commentaries deal with applications, extensions, and limitations of the findings. This “response to the respondents” focuses on Wechsler’s approach to assessment, historical antecedents of factor analysis (especially the contributions of Jacob Cohen in the 1950s), and the “intelligent testing” model of test interpretation.

We review rational and empirical reasons that comprehensive cognitive assessments are useful sources of information in the evaluation and treatment of learning disabilities. However, the existing evidence base that demonstrates the value of comprehensive cognitive assessments for this purpose is not nearly as strong as it needs to be. Proponents of comprehensive cognitive assessments for learning disability identification must do more to rigorously evaluate their beliefs or else concede the argument to those with better evidence.

The concepts of measurement and theory have always been central to psychological science. This chapter reviews the history of applied mental tests and the ideas behind them, with a specific emphasis on individually administered intellectual measures in the era of scientific psychology (i.e., after Wundt). The chapter discusses theoretical underpinnings associated with mental tests and test/theory falsifications. Beginning with the contributions of Francis Galton and J. McKeen Cattell and continuing through the present, the topics discussed include anthropometric testing, Charles Spearman’s two-factor theory and general intelligence factor, Alfred Binet and David Wechsler’s pragmatic approaches, Raymond B. Cattell and John L. Horn’s fluid and crystallized intelligence, John B. Carroll’s three-stratum model of cognitive abilities, and Alexander R. Luria’s conceptualization of brain-based, cognitive processing. The chapter closes with a discussion about theory-building and falsification in mental testing and the importance of reconciling theory with clinical practice in psychological assessment.

We examined the degree to which the conventional notion of g associated with IQ tests and general cognitive ability tests (COG-g) relate to the general ability that underlies tests of reading, math, and writing achievement (ACH-g). Two large, nationally representative data sets and two independent individually-administered set of test batteries were analyzed using confirmatory factor analysis procedures: (a) the Kaufman-II sample (N = 2520), organized into six age groups between 4–5 and 16–19 years, tested on both the Kaufman Assessment Battery for Children-2nd ed. (KABC-II) and the Kaufman Test of Educational Achievement-2nd ed. (KTEA-II) Comprehensive Form; and (b) the WJ III sample (N = 4969), organized into four age groups between 5–6 and 14–19 years, tested on both the Cognitive and Achievement batteries of the Woodcock–Johnson-3rd ed. (WJ III). Second-order latent factor models were used to model the test scores. Multi-group confirmatory factor analysis was used to investigate factor loading invariance across the age groups. In general, invariance was tenable, which allowed for valid comparisons of second-order COG-g and ACH-g factor variance/covariances and correlations across age. Although COG-g and ACH-g were not isomorphic, they correlated substantially, with an overall mean correlation coefficient of .83, and with the correlations generally increasing with age (ranging from .77 to .94). The nature of the relation between COG-g and ACH-g was explored and the best measures of COG-g were examined.

Developed in concert with the Learning Disabilities Association of America (LDA), this White Paper regarding specific learning disabilities identification and intervention represents the expert consensus of 58 accomplished scholars in education, psychology, medicine, and the law. Survey responses and empirical evidence suggest that five conclusions are warranted: 1) The SLD definition should be maintained and the statutory requirements in SLD identification procedures should be strengthened; 2) neither ability-achievement discrepancy analysis nor failure to respond to intervention alone is sufficient for SLD identification; 3) a “third method” approach that identifies a pattern of psychological processing strengths and weaknesses, and achievement deficits consistent with this pattern of processing weaknesses, makes the most empirical and clinical sense; 4) an empirically-validated RTI model could be used to prevent learning problems, but comprehensive evaluations should occur for SLD identification purposes, and children with SLD need individualized interventions based on specific learning needs, not merely more intense interventions; and 5) assessment of cognitive and neuropsychological processes should be used for both SLD identification and intervention purposes.

Flynn wrote a book devoted to the Flynn effect, featuring his theoretical explanation of why the intelligence of worldwide populations has apparently increased from generation to generation. The essence of his theorizing is that because of the societal impact of scientific technology, people of today are much more guided by abstract, rather than concrete, approaches to problem solving. He bases his theory in large part on gains on specific tasks, most notably Raven’s matrices, Wechsler Intelligence Scale for Children (WISC) Performance subtests, and, most important, on WISC Similarities. The gains on these separate tasks over more than half a century (1947-2002) are striking. However, Flynn failed to take into account the sweeping changes in test content, administration procedures, and scoring guidelines when the 1974 WISC-R was developed from the 1949 WISC. These substantial changes challenge the meaningfulness of comparing children’s performance in 1947 with their performance in 2002 on Similarities and other WISC subtests— and therefore challenge Flynn’s explanation of the effect that bears his name.

In the first article of this special issue of the Journal of Psychoeducational Assessment, I critiqued Flynn’s theoretical explanation of the Flynn effect because he depended too heavily on an apparently huge generational gain on the WISC Similarities subtest; I claimed he was comparing apples with oranges because that subtest changed too much when the WISC was first revised. Four sets of esteemed researchers were invited to respond to my article and also to an article by Zhou, Zhu, and Weiss—Flynn, Sternberg, McGrew, and Ceci and Kanaya. Flynn disagrees strongly with my critique of his theory, a theory that posits striking generational shifts from concrete (utilitarian) thinking to a kind of fluid reasoning that Flynn nicknames “scientific spectacles.” In this final article of the special issue, I respond to Flynn’s claims, and also to the points made by the other invited respondents. In addition, I respond to the range of opinions expressed by the scholars who were invited to write an essay on whether or not IQs should be adjusted for the Flynn effect in capital punishment cases (Fletcher et al., Hagan et al., and Reynolds et al.). Ultimately, I disagree with Flynn’s explanation of the Flynn effect, but I agree with his position that IQs should be adjusted for the effect in death penalty cases.

It is common practice to look at disparities among subtest scores (“scatter”) on an intelligence test to establish if a score is deviant. However, it remains unclear whether subtest scatter reflects primarily normal variation within individuals or is clinically meaningful. The present study explored this issue based on data from 467 children with developmental disabilities tested on the Dutch WISC–RNL. Of these children, 132 had learning disabilities, 178 had psychiatric disorders, and 157 had epilepsy. Subtest scatter was defined as scaled-score range (highest minus lowest scaled score). When contrasted with “normal scatter,” the overall sample revealed higher ranges on the Performance Scale and Full Scale, although effect sizes were small. Analysis of the data for the three separate clinical samples revealed unusual scatter only for the sample of children with psychiatric disorders. When comparing the clinical samples, scaled-score range was larger for the sample of children with psychiatric disorders than for those with epilepsy. Two distinct subsamples revealed elevated ranges with moderate effect sizes: children with autistic spectrum disorders and children with left hemisphere seizures. These results suggest that elevated subtest scaled-score range might characterize specific clinical samples rather than denoting an overall sign of pathology.

Age differences for nine age groups between 22 and 25 years and 81 and 90 years were evaluated, covarying educational attainment, on five Cattell-Horn-Carroll (CHC) abilities: fluid reasoning (Gf), crystallized ability (Gc), quantitative knowledge (Gq), reading (Grw-Reading), and writing (Grw-Writing). Data were from the adult portions of the stratified standardization samples of the second editions of the Kaufman Brief Intelligence Test ( N = 570) and the Kaufman Test of Educational Achievement—Brief Form ( N = 555). Gc and Grw-Reading were maintained through old age, whereas Gf, Gq, and Grw-Writing were vulnerable abilities. The age-related decline in mean scores on Gf was powerful, as even the maintained CHC abilities of Gc and Grw-Reading proved to be vulnerable when the component tasks of each were analyzed separately. All Gender × Age interactions were nonsignificant, indicating that age differences for all CHC abilities studied were essentially the same for men and women.