Does the Degree of Prematurity Relate to the Bayley-4 Scores Earned by Matched Samples of Infants and Toddlers across the Cognitive, Language, and Motor Domains?

The literature on children born prematurely has consistently shown that full-term babies outperform preterm babies by about 12 IQ points, even when tested as adolescents, and this advantage for full-term infants extends to the language and motor domains as well. The results of comprehensive meta-analyses suggest that the degree of prematurity greatly influences later test performance, but these inferences are based on data from an array of separate studies with no control of potential confounding variables such as age. This study analyzed Bayley-4 data for 66 extremely premature infants and toddlers (<32 weeks), 70 moderately premature children (32-36 weeks), and 133 full-term children. All groups were carefully matched on key background variables by the test publisher during the standardization of the Bayley-4. This investigation analyzed data on the five subtests: cognitive, expressive communication, receptive communication, fine motor, and gross motor. A multivariate analysis of covariance (MANCOVA) assessed for group mean differences across the three subsamples, while controlling for the children's age. Extremely premature children scored significantly lower than moderately premature children on all subtests, and both preterm groups were significantly outscored by the full-term sample across all domains. In each set of comparisons, the cognitive and motor subtests yielded the largest differences, whereas language development, both expressive and receptive, appeared the least impacted by prematurity. A follow-up MANOVA was conducted to examine full-term versus preterm discrepancies on the five subtests for infants (2-17 months) vs. toddlers (18-42 months). For that analysis, the two preterm groups were combined into a single preterm sample, and a significant interaction between the age level and group (full-term vs. preterm) was found. Premature infants scored lower than premature toddlers on receptive communication, fine motor, and cognitive. Neither expressive communication nor gross motor produced significant discrepancies between age groups The findings of this study enrich the preterm literature on the degree of prematurity; the age-based interactions have implications for which abilities are most likely to improve as infants grow into toddlerhood.

The Precipitous Decline in Reasoning and Other Key Abilities with Age and Its Implications for Federal Judges.

U. S. Supreme Court justices and other federal judges are, effectively, appointed for life, with no built-in check on their cognitive functioning as they approach old age. There is about a century of research on aging and intelligence that shows the vulnerability of processing speed, fluid reasoning, visual-spatial processing, and working memory to normal aging for men and women at all levels of education; even the maintained ability of crystallized knowledge declines in old age. The vulnerable abilities impact a person's decision-making and problem solving; crystallized knowledge, by contrast, measures a person's general knowledge. The aging-IQ data provide a rationale for assessing the key cognitive abilities of anyone who is appointed to the federal judiciary. Theories of multiple cognitive abilities and processes, most notably the Cattell-Horn-Carroll (CHC) model, provide a well-researched blueprint for interpreting the plethora of findings from studies of IQ and aging. Sophisticated technical advances in test construction, especially in item-response theory and computerized-adaptive testing, allow for the development of reliable and valid theory-based tests of cognitive functioning. Such assessments promise to be a potentially useful tool for evaluating federal judges to assess the impact of aging on their ability to perform at a level their positions deserve, perhaps to measure their competency to serve the public intelligently. It is proposed that public funding be made available to appoint a panel of experts to develop and validate an array of computerized cognitive tests to identify those justices who are at risk of cognitive impairment.

Relationship between reading and long-term storage and retrieval (Glr) in college students.

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 Flynn effect for fluid IQ may not generalize to all ages or ability levels: a population-based study of 10,000 US adolescents.

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 IQ<70 (95% CI=-4.9, -4.8), but increased 3.5 points among those with IQ>130 (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.

Intellectual disability and mental disorders in a US population representative sample of adolescents.

BACKGROUND: Most 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. METHODS: Data 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. RESULTS: ID 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. CONCLUSIONS: These 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.

The structure of ape (hominoidea) intelligence.

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).

Targeted Estimation of the Relationship Between Childhood Adversity and Fluid Intelligence in a US Population Sample of Adolescents.

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.

Let's Not Do Away with Comprehensive Cognitive Assessments Just Yet.

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.

Association of Fluid Intelligence and Psychiatric Disorders in a Population-Representative Sample of US Adolescents.

Importance: Despite long-standing interest in the association of psychiatric disorders with intelligence, few population-based studies of psychiatric disorders have assessed intelligence. Objective: To investigate the association of fluid intelligence with past-year and lifetime psychiatric disorders, disorder age at onset, and disorder severity in a nationally representative sample of US adolescents. Design, Setting, and Participants: National sample of adolescents ascertained from schools and households from the National Comorbidity Survey Replication-Adolescent Supplement, collected 2001 through 2004. Face-to-face household interviews with adolescents and questionnaires from parents were obtained. The data were analyzed from February to December 2016. DSM-IV mental disorders were assessed with the World Health Organization Composite International Diagnostic Interview, and included a broad range of fear, distress, behavior, substance use, and other disorders. Disorder severity was measured with the Sheehan Disability Scale. Main Outcomes and Measures: Fluid IQ measured with the Kaufman Brief Intelligence Test, normed within the sample by 6-month age groups. Results: The sample included 10 073 adolescents (mean [SD] age, 15.2 [1.50] years; 49.0% female) with valid data on fluid intelligence. Lower mean (SE) IQ was observed among adolescents with past-year bipolar disorder (94.2 [1.69]; P = .004), attention-deficit/hyperactivity disorder (96.3 [0.91]; P = .002), oppositional defiant disorder (97.3 [0.66]; P = .007), conduct disorder (97.1 [0.82]; P = .02), substance use disorders (alcohol abuse, 96.5 [0.67]; P < .001; drug abuse, 97.6 [0.64]; P = .02), and specific phobia (97.1 [0.39]; P = .001) after adjustment for a wide range of potential confounders. Intelligence was not associated with posttraumatic stress disorder, eating disorders, and anxiety disorders other than specific phobia, and was positively associated with past-year major depression (mean [SE], 100 [0.5]; P = .01). Associations of fluid intelligence with lifetime disorders that had remitted were attenuated compared with past-year disorders, with the exception of separation anxiety disorder. Multiple past-year disorders had a larger proportion of adolescents less than 1 SD below the mean IQ range than those without a disorder. Across disorders, higher disorder severity was associated with lower fluid intelligence. For example, among adolescents with specific phobia, those with severe disorder had a mean (SE) of 4.4 (0.72) points lower IQ than those without severe disorder (P < .001), and those with alcohol abuse had a mean (SE) of 5.6 (1.2) points lower IQ than those without severe disorder (P < .001). Conclusions and Relevance: Numerous psychiatric disorders were associated with reductions in fluid intelligence; associations were generally small in magnitude. Stronger associations of current than past disorders with intelligence suggest that active symptoms of psychiatric disorders interfere with cognitive functioning. Early identification and treatment of children with mental disorders in school settings is critical to promote academic achievement and long-term success.

How Much Does WAIS-IV Perceptual Reasoning Decline Across the 20 to 90-Year Lifespan When Processing Speed is Controlled?

The most prominent pattern of cognitive change over the lifespan centers on the difference between patterns of maintained abilities on tests of crystallized knowledge and patterns of steady decline on tests of problem solving and processing speed. Whereas the maintained-vulnerable dichotomy is well established in the literature, questions remain about cognitive decline in problem solving when processing speed is controlled. This relationship has been examined in cross-sectional studies that typically used non-clinical tests with non-representative samples of adults. This study extended these findings to the most popular clinical test, the Wechsler Adult Intelligence Scale -4th ed. (WAIS-IV), using its carefully stratified sample as the source of data (ages 20-90 for Indexes, ages 16-90 for Perceptual Reasoning subtests). Multivariate Analysis of Covariance (MANCOVA) revealed that 70-80% of the variance in declining reasoning ability was shared with the speed factor. This was true (a) on the index and subtest level and (b) regardless of the type of problem-solving task employed. Such robust findings have important clinical and research implications for neuropsychologists, who most frequently use the Wechsler scales as part of their assessment battery.

Gender Differences in Academic Achievement: Is Writing an Exception to the Gender Similarities Hypothesis?

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 possible societal impact of the decrease in U.S. blood lead levels on adult IQ.

BACKGROUND: 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. METHODS: 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). RESULTS: When controlling for education, gender, ethnicity, and region, the regression of IQs on BLLs was significant (r=-0.84, p<0.01); 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, p<0.01) with predicted increases of 5.2 points (95% CI, 2.4-8.0). Control analyses ruled out aging as a confounder. CONCLUSIONS: 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.

An alternative Cattell-Horn-Carroll (CHC) factor structure of the WAIS-IV: age invariance of an alternative model for ages 70-90.

The Wechsler Adult Intelligence Scale--Fourth Edition (WAIS-IV) is by the far the most popular intelligence test for the assessment of adults in clinical and neuropsychological practice. Despite a number of studies examining the factor structure of the WAIS-IV from a Cattell-Horn-Carroll (CHC) perspective (Benson, Hulac, & Kranzler, 2010; Ward, Bergman, & Hebert, 2012), a CHC interpretation of the WAIS-IV for individuals ages 70 and above has been absent from the literature. The exclusion of individuals ages 70 and above in previous research is likely due to the absence of several key supplemental subtests used to create a full CHC model. We provide an alternative five-factor CHC model of the WAIS-IV which includes only the subtests administered to individuals ages 70 and above in the standardization sample. Our results show (a) the alternative CHC model fits the data well; (b) this alternative CHC model met criteria for partial strict measurement invariance across the life span (only Similarities showed noninvariance) using strict criteria; (c) the five factors for ages 70-90 measure the same five CHC broad abilities identified in previous analyses reported for ages 16-69; and (d) the five-factor CHC solution for ages 70-90 is valid for the entire WAIS-IV age range and can be used whenever examiners administer the core battery but opt not to administer supplemental subtests.

How do educational attainment and gender relate to fluid intelligence, crystallized intelligence, and academic skills at ages 22-90 years?

Educational attainment and gender differences on fluid intelligence (Gf), crystallized intelligence (Gc), and academic skills in reading, math, and writing were analyzed for stratified adult samples ranging in age from 22 to 90 years. The data sources were the adult portions of the standardization samples of the second editions of Kaufman Brief Intelligence Test (N = 570) and the Kaufman Test of Educational Achievement-Brief Form (N = 555). Five univariate analysis of covariance were conducted with age as the covariate. Correlational analysis supplemented the covariate analyses to better understand the relationship of the five variables to education. All variables related significantly and substantially to years of formal schooling, an important finding in view of the key nature of this background variable for conducting neuropsychological assessments, as elaborated by Heaton and his colleagues. Surprisingly, Gf related just as strongly to education as did the school-related Gc. Among academic skill areas, math correlated higher with years of formal schooling than did either reading or writing. Women significantly outperformed men on the writing test and the reverse was true for the math test; other gender differences were not significant. These analyses fill a gap in the literature regarding the nature of gender and education differences in academic skills for heterogeneous samples of normal adults between young adulthood and old age and have practical implications for neuropsychological assessment.

Intra-individual subtest variability on the Dutch Wechsler Intelligence Scales for Children-Revised (WISC-R(NL)) for children with learning disabilities, psychiatric disorders, and epilepsy.

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-R(NL). 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.

Do practice effects on Wechsler's Performance subtests relate to children's general ability, memory, learning ability, or attention?

The nature of practice effects on the Wechsler Intelligence Scale-Third Edition (WISC-III) Performance Scale was examined for 51 middle-class White children ages 11 to 13 years. The participants were tested twice on the six WISC-III Performance subtests (mean interval = 13 days) to determine whether the gain scores were significantly related to the children's ability level, memory, learning ability, and attention and motivation. Measures of these constructs were administered during the initial evaluation. Results indicated that retest gains on the separate subtests were uncorrelated with each other. Multiple regression analyses yielded some significant and meaningful results (e.g., a measure of long-term memory was a significant predictor of gains on Object Assembly), but, in general, few meaningful relations were yielded in these analyses.

Development and validation of a Rasch-derived CES-D short form.

The current study presents a Rasch-derived short form of the Center for Epidemiologic Studies-Depression scale (CES-D) for use as a depression screening tool in the general population. In contrast to short forms developed with reliance on classical measurement techniques, those developed using techniques based on item response theory produce a measure that offers true interval scaling, provide enhanced information about responders with extreme scores, and expand understanding of the underlying latent structure. Cross-validation of the Rasch-derived CES-D short form supported its utility and structural validity across samples. Tests of structural validity using latent variable modeling methodology indicated that a hierarchical, single-factor model of depression had the best fit for the original full form and the Rasch-derived short form of the CES-D. This finding challenges depression researchers and theorists to reconsider the interfactor relationships in the study and assessment of depression.