Research Byte: Reevaluating the #Flynneffect, and the reversal: Temporal trends and measurement invariance in Norwegian armed forces #intelligence scores

 

Reevaluating the Flynn effect, and the reversal: Temporal trends and measurement invariance in Norwegian armed forces intelligence scores

Open access PDF available from journal Intelligence…click here.

Abstract

Since 1954, the Norwegian Armed Forces have annually administered an unchanged general mental ability test to male cohorts, comprising figure matrices, word similarities, and mathematical reasoning tests. These stable and representative data have supported various claims about shifts in general mental ability (GMA) levels, notably the Flynn effect and its reversal, influencing extensive research linking these scores with health and other outcomes. This study examines whether observed temporal trends in scores reflect changes in latent intelligence or are confounded by evolving test characteristics and specific test-taking abilities in numerical reasoning, word comprehension, and figure matrices reasoning. Our findings, using multiple-group factor analysis and multiple indicator multiple cause (MIMIC) models, indicate that while there was a general upward trend in observed scores until 1993, this was predominantly driven by enhancements in the fluid intelligence task, specifically figure matrices reasoning. Notably, these gains do not uniformly translate to a rise in underlying GMA, suggesting the presence of domain-specific improvements and test characteristic changes over time. Conversely, the observed decline is primarily due to decreases in word comprehension and numerical reasoning tests, also reflecting specific abilities not attributable to changes in the latent GMA factor. Our findings further challenge the validity of claims that changes in the general factor drive the Flynn effect and its reversal. Furthermore, they caution against using these scores for longitudinal studies without accounting for changes in test characteristics.

Research Byte: Wait, Where’s the #FlynnEffect on the #WAIS-5?

 

Emily L. Winter, 

Sierra M. Trudel, 

Alan S. Kaufman

J. Intell. 2024, 12(11), 118; https://doi.org/10.3390/jintelligence12110118

Click on the link to down open access copy of the PDF article.

The recent release of the WAIS-5, a decade and a half after its predecessor, the WAIS-IV, raises immediate questions about the Flynn effect (FE). Does the traditional FE of points per decade in the U.S. for children and adults, identified for the Full Scale IQs of all Wechsler scales and for other global IQ scores as well, persist into the 2020s? The WAIS-5 Technical and Interpretive Manual provides two counterbalanced validity studies that address the Flynn effect directly—N = 186 adolescents and adults (16–90 years, mean age = 47.8) tested on the WAIS-IV and WAIS-5; and N = 98 16-year-olds tested on the WISC-V and WAIS-5. The FE is incorporated into the diagnostic criteria for intellectual disabilities by the American Association on Intellectual and Developmental Disabilities (AAIDD), by DSM-5-TR, and in capital punishment cases. The unexpected result of the two counterbalanced studies was a reduction in the Flynn effect from the expected value of 3 IQ points to 1.2 points. These findings raise interesting questions regarding whether the three point adjustment to FSIQs should be continued for intellectual disability diagnosis and whether the federal courts should rethink its guidelines for capital punishment cases and other instances of high stakes decision-making. Limitations include a lack of generalization to children, the impact of the practice effects, and a small sample size.

Keywords: 

Flynn effect; IQ tests; cognitive assessment; Wechsler scales; WAIS-5; WAIS-IV; intelligence testing; capital punishment cases; intellectual disabilities

Law Review Article: Evaluating Intellectual Disability: Clinical Assessments in Atkins Cases (Ellis et al., 2018)

This new law review article is, IMHO, the best overview article regarding the history of ID, the legal issues in Atkins cases, and good discussion of the major conceptual and measurement issues found in many Atkins cases. An excellent introduction to ID issues in Atkins cases.

EVALUATING INTELLECTUAL DISABILITY: CLINICAL ASSESSMENTS IN ATKINS CASES

James W. Ellis, Caroline Everington, Ann M. Delpha

ABSTRACT

The intersection of intellectual disability and the death penalty is now clearly established. Both under the U.S. Supreme Court's constitutional decisions and under the terms of many state statutes, individual defendants who have that disability cannot be sentenced to death or executed. It now falls to trial, appellate, and post-conviction courts to determine which individual criminal defendants are entitled to the law's protection. This Article attempts to assist judges in performing that task. After a brief discussion of the Supreme Court's decisions in Atkins v. Virginia, Hall v. Florida, and Moore v. Texas, it analyzes the component parts and terminology of the clinical definition of intellectual disability. It then offers more detailed discussion of a number of the clinical issues that arise frequently in adjudicating these cases. For each of these issues, the Article's text and the accompanying notes attempt to provide judges with a thorough survey of the relevant clinical literature, and an explanation of the terminology used by clinical professionals. Our purpose is to help those judges to become more knowledgeable consumers of the clinical reports and expert testimony presented to them in individual cases, and to help them reach decisions that are consistent with what the clinical literature reveals about the nature of intellectual disability and best professional practices in the diagnostic process.

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Flynn Effect Reference Project update 07-31-18

The Flynn Effect Reference Project document has just been updated.  It now includes 302 references.  Access can be found at this prior post (click here)

The Flynn Effect Reference Project updated

The Flynn Effect Reference Project document, maintained at the Intellectual Competence and the Death Penalty blog, was just updated today.  This information can be found here.

Speed and the Flynn effect research study

Speed and the Flynn Effect (article link)

Olev Must and Aasa Must


Keywords: Flynn Effect NIT Speed Tork Estonia

A B S T R A C T

We investigated the role of test-taking speed on the Flynn Effect (FE). Our study compared two cohorts of Estonian students (1933/36, n = 888; 2006, n = 912) using 9 subtests from the Estonian adaptation of the National Intelligence Tests (NIT). The speededness of the items and the subtests was found by determining the proportion of unreached items from among the total number of errors (Stafford, 1971). The test-taking speed of the younger cohort was higher in all 9 of the subtests. This suggests that the younger cohort is able to solve more items than the older one. The lack of measurement invariance at the item and subtest level was quantitatively estimated using a method proposed by Dimitrov (2017). The test-taking speed and the non-invariance of the items was strongly, yet inversely correlated (up to - 0.89). The subtests versions that consisted of only invariant items showed no, or a small positive, FE. The subtest versions consisting of only speeded items showed a large positive FE, with cohort differences of up to 50%. If the requirement of measurement invariance is ignored then this effect becomes apparent. The rise in test-taking speed between cohorts can be attributed to an increase in automated responses, which is an outgrowth of modern education (differences in the mandatory age of school attendance, and in the student's readiness to solve abstract items also affected the test-taking speed of the cohorts). We were able to conclude that the younger cohort is faster than the older one.


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Research Byte: What Causes the Anti-Flynn Effect? A Data Synthesis and Analysis of Predictors

Woodley of Menie, M. A., Peñaherrera-Aguirre, M., Fernandes, H. B. F., & Figueredo, A.-J. (2017). What Causes the Anti-Flynn Effect? A Data Synthesis and Analysis of Predictors. Evolutionary Behavioral Sciences. Advance online publication.

Article link.


Abstract

Anti-Flynn effects (i.e., secular declines in IQ) have been noted in a few countries. Much speculation exists about the causes of these trends; however, little progress has been made toward comprehensively testing these. A synthetic literature search yielded a total of 66 observations of secular IQ decline from 13 countries, with a combined sample size of 302,234 and study midyears spanning 87 years, from 1920.5 to 2007.5. Multilevel modeling (MLM) was used to examine the effect of study midyear, and (after controlling for this and other factors) hierarchical general linear modeling (GLM) was used to examine the following sequence of predictors: domain “g-ness” (a rank-order measure of g saturation) Index of Biological State (IBS; a measure of relaxed/reversed selection operating on g), per capita immigration, and the 2-way interactions IBS × g-ness and Immigration × g-ness. The MLM revealed that the anti-Flynn effect has strengthened in more recent years. Net of this, the GLM found that g-ness was a positive predictor; that is, less aggregately g-loaded measures exhibited bigger IQ declines; IBS was not a significant predictor; however immigration predicted the decline, indicating that high levels of immigration promote the anti-Flynn effect. Among the interactions there was a negative effect of the Immigration × g-ness interaction, indicating that immigration promotes IQ decline the most when the measure is higher in g-ness. The model accounted for 37.1% of the variance among the observations. (PsycINFO Database Record (c) 2017 APA, all rights reserved)


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New Flynn Effect Reference Project

The new Flynn Effect Reference Project can be accessed at one of  my sister blogs (Intellectual Competence and the Death Penalty)

Sixth Circuit Court of Appeals rules (Black v Carpenter, 2017) against norm obsolescence (Flynn effect) adjustment of IQ scores in Atkins death penalty cases

A newly published 6th Circuit opinion (Black v Carpenter, 2017) rules against norm obsolescence (the Flynn effect) in the evaluation of IQ test scores in Atkins ID death penalty cases.  I obviously disagree with this decision as outlined in my 2015 chapter in the AAIDD "The Death Penalty and Intellectual Disability" (Polloway, 2015).

I have no further comment at this time as my expert opinion is clearly articulated in the AAIDD publication and I will continue my efforts to educate the courts.  This decision is at variance with the official positions of American Association on Intellectual and Developmental Disabilities (AAIDD) and the American Psychiatric Association (DSM-5), the two professional associations with official  guidance regarding  the diagnosis of ID. 

This looks like another issue that might need the attention of SCOTUS.

The following section is extracted from the complete ruling.


E. Implications of the Flynn Effect

There is good reason to have pause before retroactively adjusting IQ scores downward to offset the Flynn Effect. As we noted above, see n.1, supra, the Flynn Effect describes the apparent rise in IQ scores generated by a given IQ test as time elapses from the date of that specific test’s standardization. The reported increase is an average of approximately three points per decade, meaning that for an IQ test normed in 1995, an individual who took that test in 1995 and scored 100 would be expected to score 103 on that same test if taken in 2005, and would be expected to score 106 on that same test in 2015. This does not imply that the individual is “gaining intelligence”: after all, if the same individual, in 2015, took an IQ test that was normed in 2015, we would expect him to score 100, and we would consider him to be of the same “average” intelligence that he demonstrated when he scored 100 on the 1995-normed test in 1995. Rather, the Flynn Effect implies that the longer a test has been on the market after initially being normed, the higher (on average) an individual should perform, as compared with how that individual would perform on a more recently normed IQ test.

At first glance, of course, the Flynn Effect is troubling: if scoring 70 on an IQ test in 1995 would have been sufficient to avoid execution, then why shouldn’t a score of 76 on that same test administered in 2015 (which would produce a “Flynn-adjusted” score of 70) likewise suffice to avoid execution? Further, even if IQ tests were routinely restandardized every year or two to reset the mean score to 100, and even if old IQ tests were taken off the market so as to avoid the Flynn Effect “inflation” of scores that is visible when an IQ test continues to be administered long after its initial standardization, that would only mask, but not change, the fact that IQ scores are said to be rising.

Indeed, perhaps the most puzzling aspect of the Flynn Effect is that it is true. As Dr. Tassé states in his declaration, “[t]he so-called ‘Flynn Effect’ is NOT a theory. It is a wellestablished scientific fact that the US population is gaining an average of 3 full-scale IQ points per decade.” The implications of the Flynn Effect over a longer period of time are jarring: consider a cohort of individuals who, in 1917, took an IQ test that was normed in 1917 and received “normal” scores (say, 100, on average). If we could transport that same cohort of individuals to the present day, we would expect their average score today on an IQ test normed in 2017—a century later—to be thirty points lower: 70, making them mentally retarded, on average.

Alternatively, consider a cohort of individuals who, in 2017, took an IQ test that was normed in 2017 and received “normal” scores (of 100, on average). If we could transport that same cohort of individuals to a century ago, we would expect that their average score on a test normed in 1917 would be thirty points higher: 130, making them geniuses, on average.

It thus makes little sense to use Flynn-adjusted IQ scores to determine whether a criminal is sufficiently intellectually disabled to be exempt from the death penalty. After all, if Atkins stands for the proposition that someone with an IQ score of 70 or lower in 2002 (when Atkins was decided) is exempt from the death penalty, then the use of Flynn-adjusted IQ scores would conceivably lead to the conclusion that, within the next few decades, almost no one with borderline or merely below-average IQ scores should be executed, because their scores when adjusted downward to 2002 levels would be below 70. Indeed, the Supreme Court did not amplify just what moral or medical theory led to the highly general language that it used in Atkins when it prohibited the imposition of a death sentence for criminals who are “so impaired as to fall within the range of mentally retarded offenders about whom there is a national consensus,” 536 U.S. at 317. If Atkins had been a 1917 case, the majority of the population now living—if we were to apply downward adjustments to their IQ scores to offset the Flynn Effect from 1917 until now—would be too mentally retarded to be executed; and until the Supreme Court tells us that it is committed to making such downward adjustments, we decline to do so.

* * *

COLE, Chief Judge, concurring in the opinion except for Section II.E. I concur with the majority opinion except as to the section discussing the implications of the Flynn Effect. In holding that Black did not prove that he had significantly subaverage general intellectual functioning, we concluded that Black’s childhood IQ scores would be above 70 even if we adjusted those scores to account for both the SEM and the Flynn Effect. Accordingly, I would not address the question of whether we should apply a Flynn Effect adjustment in cases generally because it is unnecessary to the resolution of Black’s appeal. Regardless, courts, including our own in Black I, have regarded the Flynn Effect as an important consideration in determining who qualifies as intellectually disabled. See, e.g., Black v. Bell, 664 F.3d 81, 95–96 (6th Cir. 2011); Walker v. True, 399 F.3d 315, 322–23 (4th Cir. 2005).

New Wechsler Flynn Effect study by Weiss et al. (2015)

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Flynn effect methodological issues: Special issue of the Journal of Intelligence

Special Issue "Methodological Advances in Understanding the Flynn Effect

Access to this open access journal can be found here.
Quicklinks

• Special Issue Editors
• Special Issue Information
• Published Papers

A special issue of Journal of Intelligence (ISSN 2079-3200).

Deadline for manuscript submissions: closed (31 August 2015)

Special Issue Editor

Special Issue Information

Submission
Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. Papers will be published continuously (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.
Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are refereed through a peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Journal of Intelligence is an international peer-reviewed Open Access quarterly journal published by MDPI.
Please visit the Instructions for Authors page before submitting a manuscript. For the first couple of issues the Article Processing Charge (APC) will be waived for well-prepared manuscripts. English correction and/or formatting fees of 250 CHF (Swiss Francs) will be charged in certain cases for those articles accepted for publication that require extensive additional formatting and/or English corrections.

Guest Editor Prof. Dr. Joseph Lee Rodgers Department of Psychology and Human Development, Vanderbilt University, Peabody, 230 Appleton Place, Nashville, TN 37203, USA Website: http://www.vanderbilt.edu/psychological_sciences/bio/joe-rodgers

Another IQ score Flynn effect meta-analysis

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A second massive meta-analysis of the Flynn effect (norm obsolescence) was recently published (Pietschnig & Voraseck, 2015)  The study investigated different Flynn effect ability domain effects (by Gf, Gc, Gv), and other moderating variables.  However, the most important conclusion is that the authors conclude that the 3 IQ points per decade rule-of-thumb appears to be the best estimate of the FE on global IQ scores.  This conclusion is consistent with the Trahan et al. (2014) meta-analysis and the recent AAIDD recommendation.

AAIDD chapters on intellectual functioning and the Flynn effect - overdue post

I just made this post over at the Intellectual Competence and Death Penalty blog and am repeating it here for interested readers.

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It has been along time since I've been able to devote time to any of my three professional blogs.  I have been unbelievably busy with travel and professional presentations.  In fact, I have been so busy that I failed to feature two of my own recent Atkin's death penalty related book chapters that appeared in the new AAIDD book "Determining Intellectual Disability in the courts: Focus on capital cases." I have made these two chapters available via the MindHub web portal but do not believe I featured them at this blog (or at IQ's Corner).  One chapter deals with assessment of intellectual functioning issues and the other IQ test norm obsolescence (aka., the Flynn Effect).  The references (with links) are below.

McGrew, K. (2015a). Intellectual functioning. In Polloway, E. (Ed.), Determining Intellectual Disability in the courts: Focus on capital cases (pp. 85-111). Washington, DC: American Association on Intellectual and Developmental Disabilities.

McGrew, K. (2015b). Norm obsolescence: The Flynn Effect. In Polloway, E. (Ed.), Determining Intellectual Disability in the courts: Focus on capital cases (pp. 155-169). Washington, DC: American Association on Intellectual and Developmental Disabilities

Sharing The cognitive impact of the education revolution: A possible cause of the Flynn Effect on population IQ via BrowZine

The cognitive impact of the education revolution: A possible cause of the Flynn Effect on population IQ Baker, David P.; Eslinger, Paul J.; Benavides, Martin; Peters, Ellen; Dieckmann, Nathan F.; Leon, Juan Intelligence, Vol. 49 – 2015: 144 - 158

More support for the Flynn effect: Meta-Analysis of Ravens (Gf)

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Sunday, December 28, 2014

1:57 PM

 

 

Does Head Start improve g (general intelligence) or just unique subtest variance?

Interesting meta-analysis of Head Start IQ studies that suggests that improvements in IQ scores in Head Start evaluation programs are not due to changes in general intelligence (g), but are more due to short-term and transient changes to unique, specific abilities of subtests in IQ tests.

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A seminal meta-analysis of the size of the Flynn effect on IQ scores (norm obsolescence) just published

Trahan et al. (2014) have just published the most comprehensive meta-analysis of the size of the Flynn effect (norm obsolescence) to date. This is seminal work adds significant credibility to the Flynn effect as a scientific fact. Link to article above. Click on image to enlarge the abstract. I promise that one of these days I will update the Flynn Effect Archive Project. I have many other articles to add.

The Flynn effect, g, and ability differentiation

Another FE article to be added to the Flynn Effect Archive Project On next update

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New Flynn Effect study supports Rodgers (reduced IQ distribution variability) hypotheses

Double click on image to enlarge. This study will be added to next update of Flynn Effect Archive Project.



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A critical review of Dr. James Flynn's "Are we getting smarter?" book

Dr. James Flynn  recently published a new book entitled "Are we getting smarter?", where he continues to outline his theoretical explanation for the systematic increase in average IQ scores over time due to IQ test norm obsolescence  (a.k.a., the Flynn Effect - click here to visit the Flynn Effect Archive Project).

Although an appealing theoretical explanation, his theory has not meet with universal acclaim, particularly regarding the underlying research methodology and logic that is the foundation of his theory.  In a new APA PsycCITIQUES review of Flynn's new ook, Kaufman, Dillon and Kirsch (2013) present a rather scathing critique of the book ("A beautiful theory, killed by a nasty, ugly little fact").

One of Kaufman et al.'s (2013) multiple criticisms is Flynn's failure to mention an important special issue of the Journal of Psychoeducational Assessment (JPA) re: the Flynn Effect.  In this JPA issue a number of scholars (myself included; McGrew, 2010) provided a number of methodological, theoretical, and logical criticisms of the major data analytic and logical linchipins of Dr. Flynn's theory.  Yet, in his new book he  ignores the critical articles in the JPA special  issue.  Kaufman et al.'s review is a recommended reading for scholars who seek to understand the Flynn Effect and who also seek to appropriately evaluate the strengths and limitations of Flynn's theory.