Age differences within secular IQ trends: An individual growth modeling approach

It Runs in the Family: Testing for Longitudinal Family Flynn Effects

The Flynn effect refers to increases over time in measured (particularly fluid) intelligence of approximately 3 IQ points per decade. We define the Flynn effect at the family level, using longitudinal data and two new family-level cohort definitions. Multilevel growth curve analyses of the National Longitudinal Survey of Youth 1979 data showed that children in families with later-born mothers had higher average PIAT math scores, and lower average reading comprehension scores and growth, in young and middle childhood. Children in families where the first child was born later had higher average PIAT math, reading recognition, and reading comprehension scores, as well as larger developmental growth. The latter family-level Flynn effects were of higher magnitudes than the usual individual-level Flynn effect found in previous studies. Our results, showing family level-intercept and slope Flynn effects for both maternal birthyear and first child birthyear, have implications for research aiming to explain the Flynn effect.

Changes in the Intelligence Levels and Structure in Russia: An ANOVA Method Based on Discretization and Grouping of Factors

In the present paper, we investigate how the general intelligence quotient (IQ) and its subtests changed for students from Russian University from 1991 to 2013. This study of the effect of such factors as gender, department, and year on the IQ response is carried out using the ANOVA model. Given the unevenness of the initial sample by years and departments, and consequently, heterogeneity of variances when divided by the original natural categories, we decided to aggregate the values of explanatory variables to build an adequate model. The paper proposes and investigates an algorithm for joint discretization and grouping, which uses the procedure of partial screening of solutions. It is an intermediate option between the greedy algorithm and exhaustive search. As a goodness function (an optimality criterion), we investigate 26 intermediate options between the AIC and BIC criteria. The BIC turned out to be the most informative and the most acceptable criterion for interpretation, which penalizes the complexity of the model, due to some decrease in accuracy. The resulting partition of the explanatory variables values into categories is used to interpret the modeling results and to arrive at the final conclusions of the data analysis. As a result, it is revealed that the observed features of the IQ dynamics are caused by changes in the education system and the socio-economic status of the family that occurred in Russia during the period of restructuring the society and intensive development of information technologies.

Using Score Equating and Measurement Invariance to Examine the Flynn Effect in the Wechsler Adult Intelligence Scale

The Flynn effect (FE; i.e., increase in mean IQ scores over time) is commonly viewed as reflecting population shifts in intelligence, despite the fact that most FE studies have not investigated the assumption of score comparability. Consequently, the extent to which these mean differences in IQ scores reflect population shifts in cognitive abilities versus changes in the instruments used to measure these abilities is unclear. In this study, we used modern psychometric tools to examine the FE. First, we equated raw scores for each common subtest to be on the same scale across instruments. This enabled the combination of scores from all three instruments into one of 13 age groups before converting raw scores into Z scores. Second, using age-based standardized scores for standardization samples, we examined measurement invariance across the second (revised), third, and fourth editions of the Wechsler Adult Intelligence Scale. Results indicate that while scores were equivalent across the third and fourth editions, they were not equivalent across the second and third editions. Results suggest that there is some evidence for an increase in intelligence, but also call into question many published FE findings as presuming the instruments' scores are invariant when this assumption is not warranted.

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.

“Apples and Oranges Are Both Round”: Furthering the Discussion on the Flynn Effect

While the magnitude of the Flynn effect is well established (approximately 3 points a decade on the Wechsler scales), the causes behind it are still unknown and hotly debated. Kaufman argues that, because of the administrative and scoring changes that occurred with the introduction of the Wechsler Intelligence Scale for Children—Revised, Flynn’s interpretation of the effect is not appropriate. Although agreeing that these changes account for some aspects of rising IQ, this study questions the impact of these administrative/scoring changes to account for most of the impact, given the heavy documentation of the Flynn effect on multiple IQ tests and norms over time and around the world. The authors also add to the discussion led by Zhou, Zhu, and Weiss by stressing the importance of examining the role of individual differences within the Flynn effect to understand fully the exact nuances and cause(s) of it.

The Flynn Effect in the WISC Subtests Among School Children Tested for Special Education Services

The Flynn effect, a secular rise in IQ seen throughout the world, was examined on the WISC-R and WISC-III subtests in a longitudinal sample of more than 2,500 school children who were tested between 1974 and 2002. Multivariate analysis of variance and multiple regression analyses revealed that all the subtests experienced significant decreases in scores on the introduction of the WISC-III, as expected because of the Flynn effect, with the exception of Information and Digit Span. (Mazes was not included in the analyses because of a limited sample size.) On Picture Arrangement and Coding, however, children who were repeatedly tested on the WISC-III also experienced significant decreases compared with children who were repeatedly tested on the WISC-R. These findings add to the growing literature comparing the magnitude of the Flynn effect on crystallized versus fluid measures. Implications for special education testing and the current WISC-IV are discussed.

Vergleich zwischen HAWIK-III und HAWIK-IV für Testanwender

Zusammenfassung. Mit der vorliegenden Studie soll anhand eines Vergleichs zwischen HAWIK-III und HAWIK-IV, beides Versionen des Wechsler-Intelligenztests für Kinder und Jugendliche zwischen 6 und 16 Jahren, dem Testanwender eine Hilfestellung gegeben werden, wie mit den Modifikationen zwischen beiden Testversionen umgegangen werden kann. Dafür wurden 223 Kinder und Jugendliche mit beiden Testversionen untersucht. Es zeigen sich sehr hohe Korrelationen zwischen beiden Gesamt-IQ. Auf Indexebene ergaben sich höhere Korrelationen in den Indizes, die nur geringe Unterschiede zwischen HAWIK-III und HAWIK-IV aufweisen. Dagegen zeigten diejenigen Indizes niedrigere Zusammenhänge, bei denen einschneidende Veränderungen durch eine neue Untertestzusammensetzung vorgenommen wurden. Um dem Testanwender eine Richtlinie vorzugeben, welche HAWIK-IV-Werte zu erwarten sind, wenn die HAWIK-III-Ergebnisse vorliegen, wurden die erwarteten Werte und ihre Konfidenzintervalle berechnet und für ausgewählte IQ-Werte dargestellt. Die Ergebnisse der vorliegenden Studie sprechen dafür, im Regelfall den HAWIK-IV dem Vorgängerverfahren vorzuziehen. In der Verlaufsdiagnostik kann der HAWIK-III weiterhin Anwendung finden, sofern er in der Eingangsdiagnostik eingesetzt wurde.

Early school-based learning difficulties in children born very preterm

BACKGROUND

Educational underachievement is a major morbidity associated with very preterm (VPT) birth. However, few studies have examined early school outcomes with most employing global, clinic based measures.

OBJECTIVE

To examine the early school achievement in a cohort of children born VPT and studied to age 6 years.

METHODS

A regional cohort of 102 VPT children (</=33 weeks GA) were followed prospectively alongside a comparison group of 108 full term (FT) children born during the same period (1998-2000). At 6 years corrected age, all children underwent a comprehensive neurodevelopmental evaluation that included the Woodcock-Johnson Tests of Achievement (WJ-III), teacher report and national numeracy and literacy test results. Rates of specific learning disabilities (LD) were also examined.

RESULTS

VPT children performed less well than FT children on WJ-III subtests (ps<.05), national tests (ps<.01), and in all curricular areas rated by teachers (ps<.01) except expressive language. Even VPT children without severe neurodevelopmental impairment scored lower on the WJ-III math, national tests (ps<.05) and were 2-3 times more likely to show delays (ps<.02) in math (43% vs. 19%), written language (36% vs. 22%), language comprehension (26% vs. 14%), handwriting (36% vs. 17%), spelling (38% vs. 30%) and physical education (33% vs. 11%). They were also twice as likely as FT children to have math LD (47% vs. 21%).

CONCLUSIONS

By age 6, a substantial proportion of VPT children are lagging behind their FT peers across multiple curriculum areas, with difficulties being most prominent in math. Findings highlight the need for early identification and educational supports to help maximise VPT children's learning opportunities during the transition to school.

Intelligenzdiagnostik mit dem HAWIK-IV

Zusammenfassung. Im Jahr 2003 erschien in den USA die Neufassung der Wechsler Intelligence Scale for Children. Dieser Intelligenztest gehört wie die Vorgänger-Versionen weltweit zu den am häufigsten eingesetzten Testverfahren. In den vergangenen drei Jahren wurde die WISC-IV für den deutschen Sprachraum adaptiert und normiert; der Test steht als Hamburg-Wechsler-Intelligenztest für Kinder - IV (HAWIK-IV) zur Verfügung. Der HAWIK-IV stellt die grundlegende Überarbeitung des HAWIK-III bzw. der WISC-III dar. Die Revision ist geprägt durch die Einführung neuer Untertests und eine stärkere Fokussierung auf die Index-Werte. Darüber hinaus bietet der Test die Möglichkeit von detaillierten Profilanalysen, um Leistungsstärken und -schwächen eines Kindes zu erfassen. Bei einigen Untertests kann darüber hinaus durch Prozessanalysen die Aufgabenbearbeitung bewertet werden. Der HAWIK-IV wurde 2005 und 2006 in Deutschland, Österreich und der deutschsprachigen Schweiz normiert.