Effects of Age and Processing Speed on Tilt Are Primarily Linear and Additive, Not Nonlinear and Multiplicative | Published in Intelligence & Cognitive Abilities

Quick email-based blog FYI post.

 

Effects of Age and Processing Speed on Tilt Are Primarily Linear and Additive, Not Nonlinear and Multiplicative | Published in Intelligence & Cognitive Abilities 
https://icajournal.scholasticahq.com/article/146460-effects-of-age-and-processing-speed-on-tilt-are-primarily-linear-and-additive-not-nonlinear-and-multiplicative

Pardon typos and spelling errors-Message may be sent from iPhone and I've always had spelling problems :)

*****************************************
Kevin S. McGrew, PhD
Educational & School Psychologist
Director
Institute for Applied Psychometrics (IAP)
https://www.themindhub.com
******************************************

Cognitive disability might be on the rise in the U.S., particularly among younger adults

FYI quik-email posting to blog.

 

Cognitive disability might be on the rise in the U.S., particularly among younger adults 
https://www.psypost.org/cognitive-disability-might-be-on-the-rise-in-the-u-s-particularly-among-younger-adults/

Pardon typos and spelling errors-Message may be sent from iPhone and I've always had spelling problems :)

*****************************************
Kevin S. McGrew, PhD
Educational & School Psychologist
Director
Institute for Applied Psychometrics (IAP)
https://www.themindhub.com
******************************************

Individuals with higher working memory are more strategic offloaders but also greater forgetters.

This is a quick email-based FYI post to IQ's Corner.  Click link to visit journal abstract.

 

Individuals with higher working memory are more strategic offloaders but also greater forgetters. 
https://psycnet.apa.org/record/2026-85140-001

Pardon typos and spelling errors-Message may be sent from iPhone and I've always had spelling problems :)

*****************************************
Kevin S. McGrew, PhD
Educational & School Psychologist
Director
Institute for Applied Psychometrics (IAP)
https://www.themindhub.com
******************************************

The History of the #CHC Theory of #Cognitive Abilities in #Indonesia

Click on images to enlarge

Approximately seven years ago I made a post regarding the launch of the AJT CHC-based intelligence test developed and normed in Indonesia. I was the primary CHC theory and applied psychometrics consultant for the project for four years (2014 to 2017).

Unfortunately the timing of the formal AJT launch was impacted by several unanticipated factors (e.g., the lack of a mature university-based psychological assessment and interpretation training infrastructure), the most salient being the world-wide COVID pandemic.  At that time the AJT folks put the project on “pause”. To date I’ve not heard if the project has since been restarted.

I decided to check on the impact of the CHC theory of cognitive abilities in Indonesia. It was my impression, based on multiple keynote university-based CHC/AJT presentations I made during the project plus feedback from the project staff, that despite the AJT pause, the project had a major impact regarding the infusion of the CHC theory in universities (psychology departments) and private testing entities. 

To satisfy my curiosity, I performed the following Google AI queries. Below is what I I found.  Professionally I feel very proud that the four-year AJT project resulted in the quick infusion of CHC theory in the academic and private sector discourse. All entities and staff who worked on the project should be proud of the CHC impact in Indonesia.

———————————

On 11-09-2025 I, Dr. Kevin McGrew, submitted the following prompt question, followed by a second follow-up question to a Google AI search (that uses the Gemini large language model) with the Firefox web browser (version 144.0.2, released on October 28, 2025).

 

“What is the history of the CHC theory of intelligence in Indonesia?

 

The history of the Cattell-Horn-Carroll (CHC) theory of intelligence in Indonesia is relatively recent, primarily involving efforts to develop and validate locally normed intelligence tests based on the CHC framework. The theory has been recognized as the "most comprehensive theory" for structuring cognitive abilities and has been used in academic research and test development. 

 

Key milestones in the history include:

• Early 2010s: The CHC theory started gaining attention in Indonesian academic and psychological circles, leading to research interest in applying the framework. The existing intelligence tests in Indonesia at the time were few and not necessarily based on contemporary, comprehensive models like CHC theory.
• 2013-2018: The AJT Cognitive Assessment Test (AJT-CAT) Project: The most significant development began around 2013, sponsored and directed by the Yayasan Dharma Bermakna Foundation (YDB).
• This project aimed to create the first comprehensive, individually administered intelligence test in Indonesia that was natively based on the CHC theory.
• Psychometric and CHC expert Dr. Kevin McGrew served as a consultant for this project.
• The test was nationally normed using a sample of over 4,000 Indonesian individuals aged 5-18.
• The formal launch of the AJT occurred in April 2018.
• Research and Further Test Development: Since the launch of the AJT, the CHC theory has continued to serve as a foundational framework for other, more specific test development efforts.
• Researchers have developed tests for specific abilities, such as a visual-spatial ability test for high school students and a lexical knowledge test, using the CHC theory as the underlying structural model.
• These studies emphasize the use of CHC theory to ensure tests are psychometrically sound and relevant for the Indonesian context, particularly for educational and clinical assessment purposes. 

The history of CHC theory in Indonesia is marked by a shift towards developing culturally relevant, psychometrically robust assessments grounded in contemporary, internationally recognized theories of intelligence, moving beyond older or imported models.

 

What psychologist is most associated with the CHC theory in Indonesia?

 

The psychologist most prominently associated with the application and development of the Cattell-Horn-Carroll (CHC) theory in Indonesia is the American psychometric expert Dr. Kevin McGrew.  Dr. McGrew served as the primary international consultant for the development of the AJT Cognitive Assessment Test (AJT-CAT), which was the first individually administered, CHC-theory-based intelligence test developed and nationally normed in Indonesia. This project was a major collaborative effort between 2013 and 2018 involving the Yayasan Dharma Bermakna Foundation (YDB) and the Faculty of Psychology at Universitas Gadjah Mada (UGM). 

 

While the CHC theory in Indonesia involves contributions from several Indonesian researchers and institutions, Dr. McGrew is the most widely recognized figure due to his direct supervision of this foundational project and his broader international reputation as a leading scholar and "gatekeeper" of the CHC theory. 

 

Research Byte: What Explains the Relations Between Reading Comprehension and Written Composition (#CHC #Grw)? Findings from a Longitudinal Study

Click on image to enlarge

 

 

Full article: What Explains the Relations Between Reading Comprehension and Written Composition? Findings from a Longitudinal Study 
https://www.tandfonline.com/doi/full/10.1080/10888438.2025.2582620?src=#d1e329

 

"Confirmatory factor analysis revealed a strong correlation (.82) between reading comprehension and written composition".  Comment:  This finding is consistent with CHC theory where reading and writing skills form a singular broad Grw construct. 

 

This is an open access article that can be downloaded at the link above.

 

 

This post was sent via my quick email-to-blog post method.

Pardon typos and spelling errors-Message may be sent from iPhone and I've always had spelling problems :)

*****************************************
Kevin S. McGrew, PhD
Educational & School Psychologist
Director
Institute for Applied Psychometrics (IAP)
https://www.themindhub.com
******************************************

Higher fluid intelligence is associated with more structured cognitive maps

FYI post sent via my email.  I hope it works.  File under Gf in the CHC model of intelligence.

 

 

 

Higher fluid intelligence is associated with more structured cognitive maps 
https://www.psypost.org/higher-fluid-intelligence-is-associated-with-more-structured-cognitive-maps/

Pardon typos and spelling errors-Message may be sent from iPhone and I've always had spelling problems :)

*****************************************
Kevin S. McGrew, PhD
Educational & School Psychologist
Director
Institute for Applied Psychometrics (IAP)
https://www.themindhub.com
******************************************

Lets hear it for morning Java/expresso!!! - #neurocognitve #brain #cogntion #whitematter #java #coffee #morningjoe #expresso #Gf #flluidintelligence

I’ve only got one addiction I still indulge in.  Double expresso’s (actually a lungo is my preference) in the morning.  Yet another study extolling the value of Java and brain health, this time with brain white matter integrity and cortical thickness.  White matter tracts serve as the brain’s internet backbone or interestate system.  

Long live morning Joe☕️

Maybe I should bring back the IAP Gf fluid intelligence coffee mugs!

Double click to enlarge the images for easier reading

Click here to download PDF if you want to read the article.

Abstract: 

Despite associations of regular coffee consumption with fewer neurodegenerative disorders,its association with microstructural brain alterations is unclear. To address this, we examined the association of coffee consumption with brain MRI parameters representing vascular brain damage, neurodegeneration, and microstructural integrity in 2316 participants in the population-based Hamburg City Health Study. Cortical thickness and white matter hyperintensity (WMH) load were measured on FLAIR and T1-weighted images. Microstructural white matter integrity was quantified as peak width of skeletonized mean diffusivity (PSMD) on diffusion-weighted MRI. Daily coffee consumption was assessed in five groups (<1 cup, 1–2 cups, 3–4 cups, 5–6 cups, >6 cups). In multiple linear regressions, we examined the association between brain MRI parameters and coffee consumption (reference group <1 cup). After adjustment for covariates, 3–4 cups of daily coffee were associated with lower PSMD (p = 0.028) and higher cortical thickness (p = 0.015) compared to <1 cup. Moreover, 1–2 cups per day was also associated with lower PSMD (p = 0.022). Associations with WMH load or other groups of coffee consumption were not significant (p > 0.05). The findings indicate that regular coffee consumption is positively associated with microstructural white matter integrity and cortical thickness. Further research is necessary to determine longitudinal effects of coffee on brain microstructure.

Keywords: cerebral small vessel disease; coffee consumption; cortical atrophy; diffusion-weighted magnetic resonance imaging; microstructural integrity; neurodegenerative diseases; white matter hyperintensities

The effect of #processingspeed [#Gs] on academic #fluency in children with #neurodevelopmental disorders - #CHC #WISCV #WJV #intelligence #schoolpsychologists #schoolpsychology #SLD #SLD #SPED #fluency #EDPSY

Click on images to enlarge for easy reading

PDF copy of article can be downloaded here.

Abstract 

Poor processing speed (PS) is frequently observed in individuals with neurodevelopmental disorders. However, mixed findings exist on the predictive validity of such processing speed impairment and the role of working memory (WM). We conducted a retrospective chart review of patients evaluated at a developmental assessment clinic between March 2018 and December 2022. Patients with available data on the Wechsler Intelligence Scale for Children, Fifth Edition (WISC-V) and the Woodcock-Johnson, Fourth Edition, Tests of Achievement (WJ IV ACH) were included (n = 77, 69 % male; Mage = 10.6, SDage = 2.5; FSIQ range = 47–129). We performed a mediation analysis with academic fluency (AF) as the dependent variable, PS as the predictor, WM as the mediator, and academic skills and general intelligence as covariates. Both the direct and indirect effects of PS were significant prior to adding covariates. However, only the direct effect of PS was robust, independent of the effects of academic skills and general intelligence. The indirect effect of PS through WM was insignificant after accounting for the general academic skills and intelligence. Therefore, PS explains a unique variance in AF. This finding suggests that PS may be an exception to the criticism of cognitive profile analysis. Interpreting the PS score as a relative strength or weakness within a cognitive profile may uniquely predict their timed academic performance in youth with neurodevelopmental disorders.

[Do] Humans peak in midlife [?]: A combined #cognitive and #personality trait perspective - #intelligence #developmental #schoolpsychologists #schoolpsychology #CHC

Open access copy of article can be downloaded here.

 Highlights

• •
  Age trends reviewed across 16 key cognitive and personality-related dimensions.
• •
  All variables plotted on a common scale to enable direct cross-domain comparisons.
• •
  Age trajectories varied widely: some traits declined, others improved with age.
• •
  A weighted composite index of functioning was developed from theory and evidence.
• •
  Overall cognitive-personality functioning peaks between ages 55 and 60.

Abstract

Fluid intelligence, which peaks near age 20 and declines materially across adulthood, is often regarded as the most critical cognitive ability for predicting important life outcomes. Yet, human achievement in domains such as career success tends to peak much later, typically between the ages of 55 and 60. This discrepancy may reflect the fact that, while fluid intelligence may decline with age, other dimensions improve (e.g., crystallized intelligence, emotional intelligence). To examine this possibility, we analyzed age-related trends across nine constructs associated with life success: cognitive abilities, personality traits, emotional intelligence, financial literacy, moral reasoning, resistance to sunk cost bias, cognitive flexibility, cognitive empathy, and need for cognition. We extracted age-related findings from published studies for each dimension and standardized all scores to T-scores for comparability. We then constructed a Cognitive-Personality Functioning Index (CPFI) and compared two weighting approaches: a Conventional model, emphasizing intelligence and core personality traits, and a Comprehensive model, integrating a broader array of dimensions. Both models revealed a peak in overall functioning during late midlife (ages 55 to 60) but diverged at the younger and older ends of adulthood: under Conventional weighting, older adults scored well below young adults, whereas under Comprehensive weighting, the two groups were roughly equivalent. These findings suggest that functional capacity, defined in terms of key differential psychological traits, may peak in late midlife, closely aligning with the typical peak in career achievement. Also, individuals best suited for high-stakes decision-making roles are unlikely to be younger than 40 or older than 65.

Extremely important (IMHO) #CHC #cognitive #reading achievement #g+specific abilities #SEM paper - #schoolpsychology #schoolpsychologists #SPED #EDPSY #LD #SLD

Extremely interesting (important/intriging) CHC cognitive-reading achievement relations meta-SEM paper.  Why?  Because, as far as I know, it is the first g+specific abilities paper to evaluate a model with causal relations specified within and between cognitive and reading achievement CHC constructs.  Paper info below, as well as open access link to PDF.  Also, this is the first time I’ve seen a meta-structural equation modeling analysis.  Kudos to the authors.

Click on images to enlarge fo easy reading

Abstract

Cognitive tests measure psychological constructs that predict the development of academic skills. Research on cognitive–reading achievement relations has primarily been completed with single-test batteries and samples, resulting in inconsistencies across studies. The current study developed a consensus model of cognitive–reading achievement relations using meta-structural equation modeling (meta-SEM) through a cross-sectional analysis of subtest correlations from English-language norm-referenced tests. The full dataset used for this study included 49,959 correlations across 599 distinct correlation matrices.These included correlations among 1112 subtests extracted from 137 different cognitive and achievement test batteries. The meta-SEM approach allowed for increased sampling of cognitive and academic reading skills measured by various test batteries to better inform the validity of construct relations. The findings were generally consistent with previous research, suggesting that cognitive abilities are important predictors of reading skills and generalize across different test batteries and samples. The findings are also consistent with integrated cognitive–reading models and have implications for assessment and intervention frameworks.

Keywords: cognitive abilities; reading skills; cognitive–achievement relations; CHC theory;meta-structural equation modeling

IQs Corner pub alert: CHC theory of cognitive abilities used to define and evaluate AI - #AI #CHC #intelligence #schoolpsychology #schoolpsychologists #IQ #EDPSY

An exciting new paper from the Dan Hendryks et al. at the Center for AI Safety  The center is  a nonprofit with the mission “to reduce societal-scale risks from artificial intelligence.”  In this just released paper, they propose a modified CHC theory definition/framework for evaluating AI: 

• “AGI is an AI that can match or exceed the cognitive versatility and proficiency of a well-educated adult.”

Given my extensive research and publications regarding the Cattell-Horn-Carroll (CHC) theory of cognitive abilities, I was pleasantly surprised when Dan reached out for my comments and suggested revisions to the paper.  

I was extremely impressed as Dan and his group had been involved in a deep dive in the CHC literature and had developed, without my involvement, an ingenuous internet-based CHC set of “test” items that can be submitted to different AI agents (GPT-4, GPT-5, Grok) to assess their CHC broad ability domain performance (to evaluate the extent to which AI agents demonstrate the “cognitive versatility and proficiency of a well-educated adult”).  I had zero involvement in the conceptualization or development of the AI modified/adapted CHC assessment framework and resulting CHC AI metrics. 

I want to express my appreciation to Dan for including me among the list of over 24 authors.  I’m very excited to monitor future developments by Dan and his group, as well as to see the impact of the CHC theory model on AI.

Links to secure copies of the paper (in various formats and social media platforms) are listed at the bottom of this post.  

Note.  Click on all images to enlarge for easy reading

Abstract

The lack of a concrete definition for Artificial General Intelligence (AGI) obscures the gap between today's specialized AI and human-level cognition. This paper introduces a quantifiable framework to address this, defining AGI as matching the cognitive versatility and proficiency of a well-educated adult. To operationalize this, we ground our methodology in Cattell-Horn-Carroll theory, the most em-pirically validated model of human cognition. The framework dissects general intelligence into ten core cognitive domains—including reasoning, memory, and perception—and adapts established human psychometric batteries to evaluate AI systems. Application of this framework reveals a highly “jagged” cognitive profile in contemporary models. While proficient in knowledge-intensive domains, current AI systems have critical deficits in foundational cognitive machinery, particularly long-term memory storage. The resulting AGI scores (e.g., GPT-4 at 27%, GPT-5 at 58%) concretely quantify both rapid progress and the substantial gap remaining before AGI.

Modified CHC model for evaluating AI agents

Click on image to enlarge.

As mentioned in the abstract, the paper reports on the CHC AGI capabilities of GPT-4 and GPT-5 in the following figure.  Click on images to enlarge.

I was pleased to see (on page 14 of the PDF paper) the following “intelligence as processor” figure which is based on work by myself and Joel Schneider. The model in Figure 3 (below) is based on Kevin S. McGrew and W. Joel Schneider. CHC theory revised: A visual-graphic summary of Schneider and McGrew's 2018 CHC update chapter. MindHub / IAPsych working paper, 2018.  http://www.iapsych.com/mindhubpub4.pdf.  

The Schneider & McGrew (2018) heuristic CHC information processing model is below the Figure 3 figure.  Click on images to enlarge.

Dan Hendrycks and the Center AI Safety provide brief overviews describing this work on LinkedIn as well as Twitter/X (both that can be monitored for comments).

A PDF copy of the paper can be downloaded here.  A clickable web-based version of the paper can be accessed here.

Exciting stuff !!

IQs Corner: AI and the Future of Skills, Volume 1, Capabilites and Assessments - #AI #intelligence #CHC #schoolpsychology #schoolpsychologists #education

Although a four-year old publication may seem like a long time in the AI literature, readers interested in the potential interface of AI and human cognitive abilities theory and research, should take a look at this lengthy OECD report which is available free for download here. 

Of course, given my research and interests, I found Chapter 3 (of 20) of particular interest.

Right click on images to enlarge

IQs Corner. Comfortable fictions—The myth of #Gardner’s #multipleintelligences and other #educational fads (e.g., #learningstyles) - #schoolpsychology #schoolpsychologists #education #pseudoscience #intelligence

A thought provoking take at the Learning Dispatch (substack) re Gardner’s theory of multiple intelligences and other educational theories (e.g., learning styles) that appeal to comfortable fictions that “describe the reassuring stories societies tell to preserve moral comfort in the face of contradiction….these narratives about history, identity, and progress allow dominant groups to evade the moral costs of their own actions.”