Beyond reading and spelling: exploring intelligence profiles in individuals with dyslexia through a Cattell-Horn-Carroll theory lens
1
Laboratory of Psychological and Educational Tests, Gdansk, Poland
2
Institute of Psychology, University of Gdansk, Gdansk, Poland
3
Department of Psychology, Medical University of Gdansk, Gdansk, Poland
Submission date: 2025-04-11
Final revision date: 2025-06-06
Acceptance date: 2025-06-06
Online publication date: 2025-10-16
Corresponding author
KEYWORDS
TOPICS
ABSTRACT
Background:
Dyslexia, a prevalent learning disability, is associated with specific cognitive profiles. This study investigated the cognitive profiles of children and adolescents with dyslexia in Poland utilizing the Cattell-Horn-Carroll (CHC) theory to understand patterns of strengths and weaknesses.
Participants and procedure:
The study analyzed intelligence assessment data from 3,458 Polish children and adolescents (age 10-19 years) diagnosed with dyslexia. Data were obtained from a national research panel. Participants underwent comprehensive intelli-gence assessments using the Stanford-Binet Intelligence Scales, Fifth Edition (SB5). One-sample t-tests were conducted to compare the sample’s SB5 scores to population norms.
Results:
Participants with dyslexia scored significantly lower than the population average across all 18 SB5 measures (subtests and IQ indices), with effect sizes ranging from small to large. The largest deficits were observed in verbal abilities (knowledge and visual-spatial processing) and specific IQ indices including verbal IQ, general IQ, knowledge IQ, visual-spatial pro-cessing IQ, and working memory IQ.
Conclusions:
The findings support the applicability of the CHC theory in understanding the cognitive profiles of individuals with dyslexia. The study highlights specific cognitive weaknesses in crystallized intelligence, visual-spatial processing, and working memory. These results challenge the reliance on the pattern of strengths and weaknesses (PSW) model as a primary diag-nostic tool and underscore the importance of comprehensive cognitive assessments for individuals with dyslexia. These find-ings have implications for targeted interventions and a balanced approach to dyslexia diagnosis.
Dyslexia, a prevalent learning disability, is associated with specific cognitive profiles. This study investigated the cognitive profiles of children and adolescents with dyslexia in Poland utilizing the Cattell-Horn-Carroll (CHC) theory to understand patterns of strengths and weaknesses.
Participants and procedure:
The study analyzed intelligence assessment data from 3,458 Polish children and adolescents (age 10-19 years) diagnosed with dyslexia. Data were obtained from a national research panel. Participants underwent comprehensive intelli-gence assessments using the Stanford-Binet Intelligence Scales, Fifth Edition (SB5). One-sample t-tests were conducted to compare the sample’s SB5 scores to population norms.
Results:
Participants with dyslexia scored significantly lower than the population average across all 18 SB5 measures (subtests and IQ indices), with effect sizes ranging from small to large. The largest deficits were observed in verbal abilities (knowledge and visual-spatial processing) and specific IQ indices including verbal IQ, general IQ, knowledge IQ, visual-spatial pro-cessing IQ, and working memory IQ.
Conclusions:
The findings support the applicability of the CHC theory in understanding the cognitive profiles of individuals with dyslexia. The study highlights specific cognitive weaknesses in crystallized intelligence, visual-spatial processing, and working memory. These results challenge the reliance on the pattern of strengths and weaknesses (PSW) model as a primary diag-nostic tool and underscore the importance of comprehensive cognitive assessments for individuals with dyslexia. These find-ings have implications for targeted interventions and a balanced approach to dyslexia diagnosis.
REFERENCES (63)
1.
Abu-Hamour, B., & Hmouz, H. (2018). Cattell-Horn-Carroll broad cognitive ability profiles for dyslexia and intel-lectual disability. International Journal of Inclusive Education, 24, 1–17. https://doi.org/10.1080/136031....
2.
Becker, A., Daseking, M., & Kerner auch Koerner, J. (2021). Cognitive profiles in the WISC-V of children with ADHD and specific learning disorders. Sustainability, 13, 9948. https://doi.org/10.3390/su1317....
3.
Beneventi, H., Tønnessen, F. E., Ersland, L., & Hugdahl, K. (2010). Working memory deficit in dyslexia: Behavioral and fMRI evidence. International Journal of Neuroscience, 120, 51–59. https://doi.org/10.3109/002074....
4.
Callens, M., Tops, W., & Brysbaert, M. (2012). Cognitive profile of students who enter higher education with an indication of dyslexia. PLoS One, 7, e38081. https://doi.org/10.1371/journa....
5.
Carroll, J. B. (1993). Human cognitive abilities: a survey of factor-analytic studies. Cambridge University Press. https://doi.org/10.1017/CBO978....
6.
Catts, H. W., Adlof, S. M., & Ellis Weismer, S. (2006). Language deficits in poor comprehenders: a case for the simple view of reading. Journal of Speech, Language, and Hearing Research, 49, 278–293. https://doi.org/10.1044/1092-4...).
7.
Catts, H. W., Terry, N. P., Lonigan, C. J., Compton, D. L., Wagner, R. K., Steacy, L. M., Farquharson, K., & Petscher, Y. (2024). Revisiting the definition of dyslexia. Annals of Dyslexia, 74, 282–302. https://doi.org/10.1007/s11881....
8.
Cohen, J. (1988). Statistical power analysis for the behavioral sciences (2nd ed.). Lawrence Erlbaum Associates.
9.
Cowan, N. (2014). Working memory underpins cognitive development, learning, and education. Educational Psy-chology Review, 26, 197–223. https://doi.org/10.1007/s10648....
10.
De Clercq-Quaegebeur, M., Casalis, S., Lemaitre, M. P., Bourgois, B., Getto, M., & Vallée, L. (2010). Neuropsycho-logical profile on the WISC-IV of French children with dyslexia. Journal of Learning Disabilities, 43, 563–574. https://doi.org/10.1177/002221....
11.
Dombrowski, S. C., Benson N. F., & and Maki, K. E. (2025). A systematic review of the PSW diagnostic.
12.
accuracy evidence for SLD identification: Is it time to abandon PSW? School Psychology Review, 54, 363–381. https://doi.org/10.1080/237296....
13.
Everatt, J., Weeks, S., & Brooks, P. (2008). Profiles of strengths and weaknesses in dyslexia and other learning dif-ficulties. Dyslexia, 14, 16–41. https://doi.org/10.1002/dys.34....
14.
Fawcett, A., & Nicolson, R. (2017). Speed of processing, motor skill, automaticity and dyslexia. In A. Fawcett & R. Nicolson (Eds.), Dyslexia in children (pp. 157–190). Routledge. https://doi.org/10.4324/978131....
15.
Flanagan, D., McGrew, K., & Ortiz, S. (2000). The Wechsler Intelligence Scales and Gf-Gc theory: a contemporary approach to interpretation. Allyn & Bacon.
16.
Fletcher, J. M., Lyon, G. R., Fuchs, L. S., & Barnes, M. A. (2019). Learning disabilities: From identification to inter-vention (2nd ed.). The Guilford Press.
17.
Fletcher, J. M., & Miciak, J. (2019). The identification of specific learning disabilities: a summary of research on best practices. Meadows Center for Preventing Educational Risk.
18.
Floyd, R., Bergeron, R., & Alfonso, V. C. (2006). Cattell-Horn-Carroll cognitive ability profiles of poor compre-henders. Reading and Writing, 19, 427–456. https://doi.org/10.1007/s11145....
19.
Gibbons, A., & Warne, R. T. (2019). First publication of subtests in the Stanford-Binet 5, WAIS-IV, WISC-V,.
21.
Giovagnoli, G., Vicari, S., Tomassetti, S., & Menghini, D. (2016). The role of visual-spatial abilities in dyslexia: Age differences in children’s reading? Frontiers of Psychology, 7, 1997. https://doi.org/10.3389/fpsyg.....
22.
González-Valenzuela, M. J., & Martín-Ruiz, I. (2022). Neuropsychological perspective on dyslexia. In S. Misciagna (Ed.), Learning disabilities: Neurobiology, assessment, clinical features and treatments (pp. 147–176). IntechOpen. https://doi.org/10.5772/intech....
23.
Gori, S., & Facoetti, A. (2015). How the visual aspects can be crucial in reading acquisition? The intriguing case of crowding and developmental dyslexia. Journal of Vision, 15, 15.1.18. https://doi.org/10.1167/15.1.8.
24.
Grégoire, J. (2017). Interpreting the WISC-V indices. Le Journal des Psychologues, 1, 24–29.
25.
Habib, M. (2021). The neurological basis of developmental dyslexia and related disorders: a reappraisal of the temporal hypothesis, twenty years on. Brain Sciences, 11, 708. https://doi.org/10.3390/brains....
26.
Hale, J., Alfonso, V., Berninger, V., Bracken, B., Christo, C., Clark, E., Cohen, M., Davis, A., Decker, S., Denckla, M., Dumont, R., Elliott, C., Feifer, S., Fiorello, C., Flanagan, D., Fletcher-Janzen, E., Geary, D., Gerber, M., Gerner, M., … Yalof, J. (2010). Critical issues in response-to-intervention, comprehensive evaluation, and spe-cific learning disabilities identification and intervention: an expert white paper consensus. Learning Disability Quarterly, 33, 223–236. https://doi.org/10.1177/073194....
27.
Happe, F. (2013). Crystallized intelligence. In F. R. Volkmar (Ed.), Encyclopedia of autism spectrum disorders (pp. 824–825). https://doi.org/10.1007/978-1-....
28.
Hoeft, F., McCardle, P., & Pugh, K. (2015). The myths and truths of dyslexia in different writing systems. Interna-tional Dyslexia Association. Retrieved from https://dyslexiaida.org/the-my....
29.
Horn, J. L., & Noll, J. (1997). Human cognitive capabilities: Gf-Gc theory. In D. P. Flanagan, J. L. Genshaft, & P. L. Harrison (Eds.), Contemporary intellectual assessment: Theories, tests, and issues (pp. 53–91). Guilford Press.
30.
Kavale, K. A., & Forness, S. R. (2000). What definitions of learning disability say and don’t say: a critical analysis. Journal of Learning Disabilities, 33, 239–256. https://doi.org/10.1177/002221....
31.
Mather, N., & Schneider, D. (2023). The use of cognitive tests in the assessment of dyslexia. Journal of Intelligence, 11, 79. https://doi.org/10.3390/jintel....
32.
McGrew, K. (1997). Analysis of the major intelligence batteries according to a proposed comprehensive Gf-Gc framework. In D. P. Flanagan, J. L. Genshaft, & P. L. Harrison (Eds.), Contemporary intellectual assessment: Theories, tests, and issues (pp. 151–179). Guilford Press.
33.
McGrew, K., & Evans, J. (2023). Internal and external factorial extensions to the Cattell-Horn-Carroll (CHC) theory of cognitive abilities: a review of factor analytic research since Carroll’s seminal 1993 treatise. Carroll Human Cognitive Abilities (HCA) Project Research Report.
34.
McGrew, K. S. (2009). CHC theory and the human cognitive abilities project: Standing on the shoulders of the giants of psychometric intelligence research. Intelligence, 37, 1–10. https://doi.org/10.1016/j.inte....
35.
McGrew, K. S., & Flanagan, D. P. (1998). The intelligence test desk reference (ITDR): Gf-Gc cross-battery assess-ment. Allyn & Bacon.
36.
McGrew, K. S., Schneider, W. J., Decker, S. L., & Bulut, O. (2023). A psychometric network analysis of CHC intel-ligence measures: Implications for research, theory, and interpretation of broad CHC scores “beyond g”. Journal of Intelligence, 11, 19. https://doi.org/10.3390/jintel....
37.
McInnes, A., Humphries, T., Hogg-Johnson, S., & Tannock, R. (2003). Listening comprehension and working memory are impaired in attention-deficit hyperactivity disorder irrespective of language impairment. Journal of Abnormal Child Psychology, 31, 427–443. https://doi.org/10.1023/a:1023....
38.
Moll, K., Kunze, S., Neuhoff, N., Bruder, J., & Schulte-Körne, G. (2014). Specific learning disorder: Prevalence and gender differences. PLoS One, 9, e103537. https://doi.org/10.1371/journa....
39.
Olech, M., Jurek, P., Radtke, B. M., Sajewicz-Radtke, U., & Łada-Maśko, A. (2024). Intelligence assessment of chil-dren and youth benefiting from psychological-educational support system in Poland. Scientific Data, 11, 826. https://doi.org/10.1038/s41597....
40.
Pennington, B. F. (2006). From single to multiple deficit models of developmental disorders. Cognition, 101, 385–413. https://doi.org/10.1016/j.cogn....
41.
Peterson, R. L., & Pennington, B. F. (2015). Developmental dyslexia. Annual Review of Clinical Psychology, 11, 283–307. https://doi.org/10.1146/annure....
42.
Poletti, M. (2016). WISC-IV intellectual profiles in Italian children with specific learning disorders and related im-pairments in reading, written expression, and mathematics. Journal of Learning Disabilities, 49, 320–335. https://doi.org/10.1177/002221....
43.
Richlan, F. (2020). The functional neuroanatomy of developmental dyslexia across languages and writing systems. Frontiers in Psychology, 11, 155. https://doi.org/10.3389/fpsyg.....
44.
Richlan, F., Kronbichler, M., & Wimmer, H. (2011). Meta-analyzing brain dysfunctions in dyslexic children and adults. NeuroImage, 56, 1735–1742. https://doi.org/10.1016/j.neur....
45.
Roid, G. H. (2003). Stanford-Binet Intelligence Scales (5th ed.). Riverside Publishing.
46.
Roid, G. H., Sajewicz-Radtke, U., Radtke, B. M., & Lipowska, M. (2017). Skala inteligencji Stanford-Binet, edycja piąta [Stanford-Binet Intelligence Scales, Fifth Edition]. Pracownia Testów Psychologicznych i Pedagogicz-nych.
47.
Schneider, W. J., & McGrew, K. S. (2018). The Cattell-Horn-Carroll theory of cognitive abilities. In D. P. Flanagan & E. M. McDonough (Eds.), Contemporary intellectual assessment: Theories, tests, and issues (4th ed., pp. 73–163). Guilford Press.
48.
Schultz, E. K., Simpson, C. G., & Lynch, S. A. (2012). Specific learning disability identification: What constitutes a pattern of strengths and weaknesses? Learning Disabilities, 18, 87–97.
49.
Shaywitz, S. E., & Shaywitz, B. A. (2005). Dyslexia (specific reading disability). Biological Psychiatry, 57, 1301–1309. https://doi.org/10.1016/j.biop....
50.
Shaywitz, S. E., Shaywitz, J. E., & Shaywitz, B. A. (2021). Dyslexia in the 21st century. Current Opinion in Psychia-try, 34, 80–86. https://doi.org/10.1097/yco.00....
51.
Snowling, M. J., Charles, H., & Nation, K. (2020). Defining and understanding dyslexia: Past, present and future. Oxford Review of Education, 46, 501–513. https://doi.org/10.1080/030549....
52.
Stanovich, K. E. (2008). Matthew effects in reading: Some consequences of individual differences in the acquisi-tion of literacy. The Journal of Education, 189, 23–55. https://doi.org/10.1177/002205....
53.
Stein, J. (2014). Dyslexia: The role of vision and visual attention. Current Developmental Disorders Reports, 1, 267–280. https://doi.org/10.1007/s40474....
54.
Swanson, H. L., & Berninger, V. W. (1996). Individual differences in children’s working memory and writing skill. Journal of Experimental Child Psychology, 63, 358–385. https://doi.org/10.1006/jecp.1....
55.
Taroyan, N. A., Nicolson, R. I., & Fawcett, A. J. (2007). Behavioural and neurophysiological correlates of dyslexia in the continuous performance task. Clinical Neurophysiology, 118, 845–855. https://doi.org/10.1016/j.clin....
56.
Tobia, V., & Marzocchi, G. M. (2014). Cognitive profiles of Italian children with developmental dyslexia. Reading Research Quarterly, 49, 437–452. http://www.jstor.org/stable/43....
57.
Toffalini, E., Giofrè, D., & Cornoldi, C. (2017). Strengths and weaknesses in the intellectual profile of different sub-types of specific learning disorder: a study on 1,049 diagnosed children. Clinical Psychological Science, 5, 216770261667203. https://doi.org/10.1177/216770....
58.
USA (2011). Individuals with Disabilities Education Improvement Act of 2004. ProQuest. Retrieved from https://search.library.wisc.ed....
59.
Vellutino, F. R., Fletcher, J. M., Snowling, M. J., & Scanlon, D. M. (2004). Specific reading disability (dyslexia): What have we learned in the past four decades? Journal of Child Psychology and Psychiatry, 45, 2–40. https://doi.org/10.1046/j.0021....
60.
Vidyasagar, T. R., & Pammer, K. (2010). Dyslexia: a deficit in visuo-spatial attention, not in phonological pro-cessing. Trends in Cognitive Sciences, 14, 57–63. https://doi.org/10.1016/j.tics....
61.
Wechsler, D. (2014). Wechsler Intelligence Scale for Children (5th ed.). Pearson.
62.
Yang, L., Li, C., Li, X., Zhai, M., An, Q., Zhang, Y., Zhao, J., & Weng, X. (2022). Prevalence of developmental dys-lexia in primary school children: a systematic review and meta-analysis. Brain Sciences, 12, 240. https://doi.org/10.3390/brains....
63.
Zeffiro, T., & Eden, G. (2000). The neural basis of developmental dyslexia. Annals of Dyslexia, 50, 1–30. https://doi.org/10.1007/s11881....
Copyright: © Institute of Psychology, University of Gdansk This is an Open Access journal, all articles are distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) License (https://creativecommons.org/licenses/by-nc-sa/4.0/), allowing third parties to copy and redistribute the material in any medium or format and to remix, transform, and build upon the material, provided the original work is properly cited and states its license.
| eISSN: | 2353-5571 |
| ISSN: | 2353-4184 |
We process personal data collected when visiting the website. The function of obtaining information about users and their behavior is carried out by voluntarily entered information in forms and saving cookies in end devices. Data, including cookies, are used to provide services, improve the user experience and to analyze the traffic in accordance with the Privacy policy. Data are also collected and processed by Google Analytics tool (more).
You can change cookies settings in your browser. Restricted use of cookies in the browser configuration may affect some functionalities of the website.
You can change cookies settings in your browser. Restricted use of cookies in the browser configuration may affect some functionalities of the website.
