Cognitive Aging Revisited: A Cross-Sectional Analysis of the WAIS-5

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Prior cross-sectional research shows crystallized abilities increase from adolescence through the 50s or 60s and are maintained until about age 75, then decline rapidly, while fluid abilities and processing speed peak in the 20s and decline steadily thereafter.

“In general, prior cross-sectional research shows increases in crystallized abilities from adolescence through to one’s 50s or 60s, and maintenance until about age 75, before these abilities decline rapidly into old age (Kaufman and Horn 1996); by contrast, fluid abilities and processing speed peak during one’s 20s, and then display a steady and often precipitous decline through to old age (Kaufman”

• cites Kaufman and Horn 1996 sourcePartly supported

  Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  Experimental — accuracy not yet measured
• cites Kaufman et al. 2016 sourceNot checked — no full text of the source
• cites Salthouse 2010, 2014Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S3 (load-bearing).

Educational attainment is linked to higher cognitive function performance later in life, a concept known as the cognitive reserve hypothesis.

“Educational attainment, the highest level of education completed, has been linked to higher cognitive function performance later in life, a concept known as the “cognitive reserve hypothesis” (Ackerman 2005; Lenehan et al. 2015; Wilson et al. 2009).”

• cites Ackerman 2005Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Lenehan et al. 2015 sourceSupported
• cites Wilson et al. 2009 sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing).

Salthouse (2014) notes that cross-sectional findings align closely with cognitive declines observed in quasi-longitudinal studies of Wechsler's scales.

“Importantly, Salthouse (2014) notes that these cross-sectional findings align closely with cognitive declines observed in “quasi-longitudinal” studies of Wechsler’s scales, which follow the changes in ability level of independent samples from the same cohorts (years of birth) over decades (Kaufman 1990, 2001; Lichtenberger and Kaufman 2013).”

• cites Salthouse 2014 sourceSupported

May combine two claims.

These results align with previous cross-sectional studies in terms of the crest and decline, but the stability in the profile throughout middle age was relatively novel compared to WAIS-III findings, which indicated a more drastic downturn.

“These results align with findings from previous cross-sectional studies (Kaufman 2001; Kaufman and Horn 1996) in terms of the “crest” and decline; however, the stability in the profile throughout middle age was relatively novel in comparison to the WAIS-III’s findings (Kaufman 2001), which indicated a more drastic downturn.”

• cites Kaufman 2001 sourceNot checked — no full text of the source
• cites Kaufman and Horn 1996 sourceSupported

May combine two claims.

The present results are consistent with previous cross-sectional results from every Wechsler scale since Wechsler-Bellevue, Salthouse's analyses, Woodcock-Johnson results, and adult versions of Kaufmans' tests, providing strong evidence that intelligence is measured by Wechsler's scales.

“the present results are consistent with previous cross-sectional results—from every Wechsler scale since Wechsler–Bellevue”

• Also stated in: § 4. Discussion · boosted

  “providing strong evidence that intelligence is indeed measured by Wechsler’s scales.”

• cites Salthouse 2010, 2014, 2016, 2019Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites McArdle et al. 2002 sourceNot checked — no full text of the source
• cites Kaufman and Horn 1996 sourcePartly supported

  Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  Experimental — accuracy not yet measured

May combine two claims.

The present study conforms with the results of a huge body of prior research, extending these findings to data obtained in 2023, post-pandemic, on the WAIS-5.

“The present study, using cross-sectional methodology, conforms with the results of a huge body of prior research (Kaufman 2021; Salthouse 2019), extending these findings to data obtained in 2023, post-pandemic, on the latest version of Wechsler’s adult scales, the WAIS-5.”

• cites Kaufman 2021 sourceSupported
• cites Salthouse 2019 sourceSupported

• AssumptionRests on an assumption: The WAIS-5 will replace the WAIS-IV as the go-to clinical test worldwide as translations and adaptations of the WAIS-5 proliferate.

May combine two claims.

Visual spatial, fluid reasoning, and working memory abilities all show a decline in cognitive skills across ages, seen more sharply after age 45.

“All three cognitive abilities show a decline in cognitive skills across ages, which is seen more sharply after age 45 (see Figure 3, Figure 4 and Figure 5).”

May combine two claims.

Processing speed ability shows consistent decline across age groups, starting within the youngest age group (20-24).

“Figure 2 displays the consistent decline in processing speed ability across the age groups, which demonstrates steady decline starting within the youngest age group (the 20–24 age bracket).”

May combine two claims.

Verbal comprehension skills peaked at ages 45-54 for both education-adjusted and non-education-adjusted means, remaining relatively stable through ages 70-74.

“As observed in Figure 1, verbal comprehension skills peaked at ages 45–54 for both education-adjusted and non-education-adjusted means, remaining relatively stable through ages 70–74.”

May combine two claims.

The Peak Age was 45-54 for VCI, 20-24 for VSI, PSI, FRI, and FSIQ, and 25-29 for WMI.

“The Peak Age was 45–54 for VCI, 20–24 for VSI, PSI, FRI, and FSIQ, and 25–29 for WMI.”

May combine two claims.

Working memory maintains the longest among the vulnerable abilities, showing the greatest decline after age 70.

“Working memory maintains the longest among the vulnerable abilities, showing the greatest decline after age 70.”

May combine two claims.

Working memory maintains the highest score throughout aging; it is a vulnerable ability, but not to the extreme extent of fluid reasoning and visual spatial skills.

“Working memory maintains the highest score throughout aging; it is a vulnerable ability, but not to the extreme extent of fluid reasoning and visual spatial skills.”

May combine two claims.

Working memory was vulnerable to the aging process but demonstrated slower patterns of decline than the other vulnerable abilities.

“Working memory was vulnerable to the aging process but demonstrated slower patterns of decline than the other vulnerable abilities.”

May combine two claims.

VSI and FRI have periods of alternating decline and plateaus, whereas WMI displays a spikier pattern of decreases, increases, and plateaus.

“As visually noted in the charts, VSI and FRI (Figure 4 and Figure 5) have periods of alternating decline and plateaus, whereas WMI displays a “spikier” pattern of decreases, increases, and plateaus.”

May combine two claims.

Verbal skills were maintained through late middle age, but joined the vulnerable abilities of working memory, fluid reasoning, visual spatial ability, and processing speed with dramatic decline between ages 75 and 90.

“Verbal skills were maintained through late middle age, but joined the vulnerable abilities of working memory, fluid reasoning, visual spatial ability, and processing speed with its dramatic decline between ages 75 and 90.”

May combine two claims.

Although PRI on the WAIS-IV was split into VSI and FRI on the WAIS-5, the two new scales, though measuring separate and distinct CHC abilities, displayed virtually identical aging patterns in the analyses.

“Although PRI on the WAIS-IV was split into VSI and FRI on the WAIS-5, it is notable that the two new scales, though measuring separate and distinct CHC abilities, displayed virtually identical aging patterns in our analyses.”

May combine two claims.

Outside verbal comprehension, the Peak Age is the youngest group (20-24) for visual spatial, fluid reasoning, processing speed, and Full-Scale IQ, and the second youngest group (25-29) for working memory.

“Outside of verbal comprehension skills (i.e., crystalized intelligence), the “Peak Age” is the youngest group (20–24) for visual spatial, fluid reasoning, processing speed, and Full-Scale IQ, and the second youngest group (25–29) for working memory.”

May combine two claims.

When the differential rates of decline of the five abilities measured by the WAIS-5 are integrated into a single 7-subtest global score, FSIQ maintains through age 54 (mean for ages 45-54 = 97.8) before declining steadily to a borderline mean of 77.8 at ages 85-90.

“when the differential rates of decline of the five abilities measured by the WAIS-5 are integrated into a single 7-subtest global score, the FSIQ is seen to maintain through age 54 (mean for ages 45–54 = 97.8) before declining steadily to a “borderline” mean of 77.8 at ages 85–90 (see Table 2).”

May combine two claims.

Crystallized abilities, often interpreted as maintained throughout lifespan, were found to decline precipitously after age 75, no different from vulnerable abilities.

“Crystallized abilities, so often interpreted as being maintained throughout one’s lifespan—if not increasing, then at least reaching a plateau—were found to decline precipitously after age 75, no different from the so-called vulnerable abilities.”

May combine two claims.

Processing speed shows the largest difference scores from the Peak Age group, with large effect sizes for the standard deviation differences present starting in the mid-60s.

“Processing speed shows the largest difference scores from the Peak Age group, with large effect sizes for the standard deviation differences present starting in the mid-60s.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

The control for educational attainment has less impact when each age group through to the 70s has the same level of education.

“Furthermore, the control for educational attainment has less impact when each age group through to the 70s has the same level of education.”

May combine two claims.

Educational attainment is strongly linked to the level of cognitive functioning throughout one's lifespan but not necessarily to the trajectory of cognitive decline.

“These findings underscore that educational attainment is strongly linked to the level of cognitive functioning throughout one’s lifespan but not necessarily to the trajectory of cognitive decline.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The WAIS-5 is a highly used measure of intelligence with strong demonstrated evidence of reliability and validity across all ages from 16 to 90 years.

“The present study utilized the WAIS-5 (Wechsler et al. 2024a, 2024b), a highly used measure of intelligence with strong demonstrated evidence of reliability and validity displayed across all ages (i.e., 16 to 90 years).”

• cites Wechsler et al. 2024a, 2024bNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S3 (load-bearing).

Higher educational attainment correlates with higher Full-Scale IQs.

“Higher educational attainment correlated with higher Full-Scale IQs (FSIQ).”

• cites Kaufman et al. 2016 sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S2 (checkable).

Education is a powerful cohort effect that must be controlled to the degree possible when comparing the intelligence of adults in different age groups.

“As such, education is a powerful cohort effect that must be controlled to the degree possible when comparing the intelligence of adults in different age groups.”

• AssumptionRests on an assumption: At any given point in time, young adults on average have the highest degree of formal education, whereas older adults have the least.

Probably not a substantial claim: may not pass S3 (load-bearing).

Data were gathered by NCS Pearson to be representative of the U.S. Census at designated intervals.

“Data were gathered by NCS Pearson to be representative of the U.S. Census at designated intervals—some at 5-year intervals and some at 10-year intervals.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Cross-sectional design does not control for cultural factors, such as pivotal experiences in specific generations, including the COVID-19 pandemic.

“Cross-sectional design, however, does not control for cultural factors (i.e., generational factors), such as pivotal experiences in specific generations, including the COVID-19 pandemic.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Index reliability coefficients ranged from 0.90 to 0.98 on the WAIS-IV and 0.90 to 0.97 on the WAIS-5.

“Index reliability coefficients ranged from 0.90 to 0.98 on the WAIS-IV and 0.90 to 0.97 on the WAIS-5 (see Table 4.1 in Wechsler 2008; Wechsler et al. 2024b).”

• cites Wechsler 2008Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Wechsler et al. 2024bNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The WAIS-5 includes a shift from a four-factor to a five-factor model, splitting Perceptual Reasoning into Visual Spatial and Fluid Reasoning indices.

“Most notably, the WAIS-5 includes a shift from a four-factor to a five-factor model. The previous factors were VCI, Perceptual Reasoning (PRI), WMI, and PSI. The WAIS-5 split and restructured the PRI into the VSI and FRI, aligning more closely with CHC broad abilities.”

• cites Wechsler et al. 2024a, 2024bNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S3 (load-bearing).

The study was not preregistered.

“The study was not preregistered.”

May combine two claims.

Meta-analytic findings suggest education plays a critical role in maintaining higher levels of cognitive performance but does not demonstrate a consistent association with the rate of cognitive aging.

“For instance, meta-analytic findings suggest that while education plays a critical role in maintaining higher levels of cognitive performance, education does not demonstrate a consistent association with the rate of cognitive aging (Seblova et al. 2020).”

• cites Seblova et al. 2020 sourceNot checked — no full text of the source

May combine two claims.

The sample included 180 participants per age group for ages 20-24 through 85-90, totaling n = 1660 and mapping 11 age groups.

“Specifically, 180 participants comprised each age group for individuals aged 20–24 through 85–90 (n = 1660), which mapped 11 different age groups.”

Probably not a substantial claim: may not pass S1 (asserted).

The maintenance of VCI is unrelated to the changes in construct from VIQ to VCI.

“thus, we hypothesize that the maintenance is unrelated to the changes in construct.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The WAIS-5 features updated norms and streamlined administration for shorter administration times as well as data collected exclusively following the COVID-19 pandemic.

“The WAIS-5 features updated norms and streamlined administration for shorter administration times as well as features data collected exclusively following the COVID-19 pandemic.”

• cites Wechsler et al. 2024a, 2024bNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Classified as probably not a substantial claim. May combine two claims.

The sample included adult participants aged 20-24 through 85-90 (n = 1660), mapped into 11 age groups.

“The sample included adult participants aged 20–24 through 85–90 (n = 1660), which were mapped into 11 age groups.”

May combine two claims.

The replication of pre-pandemic data in the contemporary adult population suggests that whatever effect the COVID-19 pandemic might have on children's intelligence, it might not be as potent a variable for the adult population.

“all data were obtained post-COVID-19 pandemic; the replication of pre-pandemic data within the contemporary adult population suggests that whatever effect the pandemic might have on children’s intelligence, it might not be as potent a variable for the adult population”

• cites Trudel et al. forthcomingNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Classified as probably not a substantial claim. May combine two claims.

Prior scholars using cross-sectional methodology have long proposed maintained crystallized abilities at least through late middle age, contrasted with vulnerable working memory, processing speed, and problem solving, with decline in vulnerable abilities beginning early in one's 20s and continuing steadily through the oldest age tested.

“Prior scholars using cross-sectional methodology who examined cognitive aging have long proposed the concept of maintained crystallized abilities, at least through late middle age, contrasted with vulnerable working memory, processing speed, and problem solving (visual spatial and fluid); the sometimes dramatic decline in vulnerable abilities has shown to begin early (in one’s 20s) and continue”

• cites Kaufman 2001, 2021Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Kaufman et al. 2016 sourceNot checked — no full text of the source
• cites Salthouse 2010, 2014, 2016, 2019Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S3 (load-bearing).

Ample evidence shows that those with more educational attainment start off with higher cognitive scores than those with lower education.

“Ample evidence shows that those with more educational attainment start off with higher cognitive scores than those with lower education (e.g., Lichtenberger and Kaufman 2013).”

• cites Lichtenberger and Kaufman 2013Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Classified as probably not a substantial claim.

The normative sample collected by NCS Pearson had exclusionary criteria, such as individuals with intellectual disabilities, psychiatric disorders, and neurological conditions.

“the normative sample collected by NCS Pearson had exclusionary criteria, such as individuals with intellectual disabilities, psychiatric disorders, and neurological conditions.”

May combine two claims.

The cross-sectional design compares adults from different age cohorts, and any observed differences might be contaminated by cohort differences owing to societal or generational changes or events.

“an immediate limitation is that the design compares adults from different age cohorts, and any observed differences might be contaminated by cohort difference owing to societal or generational changes or events (e.g., war, pandemics, medical advancements, Schaie 2012).”

• cites Schaie 2012 sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

WAIS-5 normative sample data were aligned with the 2022 U.S. census.

“WAIS-5 normative sample data (aligned with the 2022 U.S. census) were obtained from the test publisher.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

From the third to the fifth edition of WAIS, Verbal Comprehension (WAIS-5) and Verbal IQ (WAIS-III) are not identical constructs.

“It is important to note that from the third to the fifth edition of WAIS, Verbal Comprehension (WAIS-5) and Verbal IQ (WAIS-III) are not identical constructs.”

May combine two claims.

Internal consistency of the WAIS-5 components is evident from moderate but substantial correlations across subtests and indexes and from strong g factors in all exploratory and confirmatory factor analyses.

“Point “a” is evident from moderate but substantial correlations across subtests and indexes and from the emergence of strong g factors in all exploratory and confirmatory factor analyses.”

May combine two claims.

Factor analysis evidence for the WAIS-5 is evident from EFA and CFA results, and each of the five WAIS-5 Indexes corresponds to a major broad ability in CHC theory, with working memory and processing speed factors aligning with relevant theories.

“Point “b” is evident from the results of EFA and CFA, as well as the ability represented by each of the five separate WAIS-5 Indexes corresponds to a major broad ability in CHC theory and the working memory and processing speed factors aligning well with the relevant theories of working memory and neuroscience on which the test battery is partially built upon.”

May combine two claims.

Mean standard scores for all age groups are based on conversion tables for ages 25 to 34-year-olds, providing a common yardstick for comparing the 11 age groups.

“Mean standard scores for all age groups are based on the conversion tables for ages 25 to 34-year-olds, which provides a common yardstick for comparing the 11 age groups’ gains and declines between young adulthood and old age”

Classified as probably not a substantial claim. May combine two claims.

Three crucial aspects of construct validity for an IQ test, according to Urbina (2014) and Anastasi, are internal consistency of components, factor analysis tying factors to theoretical constructs, and lawful age changes across the age range.

“three of the crucial aspects of construct validity for an IQ test, according to Susanna Urbina (2014) and her mentor—legend Anne Anastasi—are (a) the internal consistency of its components, (b) factor analysis that ties each factor to a theoretical construct, and (c) lawful age changes across the age range.”

• cites Urbina 2014 sourceNot checked — no full text of the source

May combine two claims.

A more sophisticated control of educational attainment than in previous cross-sectional investigations was applied, namely post-stratification weighting, providing an excellent control of this potent, potentially contaminating, cohort variable.

“attainment was applied than has been used in previous cross-sectional investigations, namely post-stratification weighting, providing an excellent control of this potent, and potentially contaminating, cohort variable”

• Also stated in: § 4.1. Limitations · boosted

  “We controlled for one known, and powerful, cohort variable, namely educational attainment”

• AssumptionRests on an assumption: Educational attainment is a potent, potentially contaminating cohort variable.