Does the Flynn Effect Affect IQ Scores of Students Classified as LD?

Abstract

This research examined two samples of students classified as learning disabled (LD) for evidence of the phenomenon known as the Flynn effect (FE;Flynn, 1999). Triennial test data were collected for two samples. Sample 1 included students tested twice with the Wechsler Intelligence Scale for Children-Third Edition (WISC-III; n ϭ 59). Sample 2, the primary data set, included students tested first with the Wechsler Intelligence Scale for Children-Revised (WISC-R), and then with the WISC-III ( n ϭ 171). A secondary analysis examined potential differences in the FE by ethnicity and/or gender. Results indicate that the FE does affect Wechsler IQ and component scores of students classified as LD. Further, the effect varies by task. There were no significant differences in the FE by race and/or gender. The study suggests that LD classification may be substantially impacted by the Over the years, several studies have reported a decrease in students' IQ scores between different revisions of popular intelligence tests such as the

The Flynn Effect and Its Clinical Implications

“…Kanaya and Ceci (2012) recently investigated the potential effects of the FE on the diagnosis of specific learning disorders. This research, similar to previous studies (Gaskill & Brantley, 1996;Truscott & Frank, 2001), used logistic regression analyses for examining the changes in diagnoses of learning disability across time after a new assessment. This study showed a significant decrease in the number of children eligible for special education programs, partially due to the FE.…”

A Comparison of WAIS‐R and WAIS‐III in the Lower IQ Range: Implications for Learning Disability Diagnosis

“…Some researchers have found that the Flynn effect is uniform across the borderline (Full Scale IQ 70–80) and mental retardation (Full Scale IQ <70) intellectual ability levels (Kanaya et al. 2001; Truscott & Frank 2001), but others have found it to be smaller in those with lower IQ, and that it can even reverse for those with scores in the learning disability range (Spruill & Beck 1988; Spitz 1989).…”

“…Truscott & Frank (2001) analysed the Wechsler Intelligence Scale for Children‐Revised (WISC‐R; Wechsler 1974) and the more recent Wechsler Intelligence Scale for Children‐Third Edition (WISC‐III; Wechsler 1991) scores for a sample of children receiving special education because of learning difficulties ( n = 171). However, only children with an IQ of 80 or more were included in the sample, as Spitz 1989 reported an atypical effect of the Flynn effect in children with mental retardation (children with a diagnosis of mental retardation typically have a Full Scale IQ of <70).…”

“…In the Truscott & Frank (2001) study a large gap between test administrations means that the participants’ history was not controlled for [the average time between test administration was 3.32 years (SD, 0.99)]. As the authors suggest, it may have been beneficial to have administered the WISC‐R and the WISC‐III at approximately the same time to ensure that participants’ histories did not differentially affect performance on the IQ tests.…”

Differences between WISC‐R and WISC‐III performance scale among children with ADHD

“…Flynn and others have documented an upward drift in normative performances on intelligence tests (Carlton & Sapp, 1997;Flynn, 1985Flynn, , 1987Truscott & Frank, 2001.). Known as the "Flynn effect," these score increases in the United States amount to approximately three points per decade.…”