Does the Flynn Effect Differ by IQ Level in Samples of Students Classified as Learning Disabled?

Abstract

This research examined scores from two learning-disabled (LD) samples for evidence of the Flynn Effect (FE; Flynn, 1999) to determine (a) whether the FE was evident, and (b) if the magnitude of the FE differed on IQ scores at varying levels of intelligence. Sample 1 consisted of 40 children who were administered the Woodcock-Johnson Tests of Cognitive Ability-Revised (WJ-R Cog) and the Woodcock-Johnson Tests of Cognitive Ability-Ill (WJ-III Cog) approximately 8 weeks apart. Sample 2 consisted of triennial test data for 169 students who were tested once with the Wechsler Intelligence Scale for Children-Revised (WISC-R) and 3 years later with the Wechsler Intelligence Scale for Children-Third Edition (WISC-III). After an initial analysis for the overall FE, Samples 1 and 2 were each divided into IQ level groups (e.g., 91-105) and analyzed accordingly. Results for Sample 1 (W-J) indicated that the 2+ point observed IQ change was not significant for this relatively small sample, although it appeared to be consistent with the direction and degree predicted by the FE (Flynn, 1984). Results for Sample 2 (WISC) indicated a significant IQ change consistent with the FE. Neither sample exhibited statistically significant differences for FE by IQ level. However, consistent with previous research, observed differences increased from lower to higher IQ levels. Consequently, this research cannot rule out the possibility that a child's IQ level influences the degree to which the FE is apparent.

References

Atkinson, L. (1991). Three standard errors of measurement and the Wechsler Memory Scale-Revised. Psychological Assessment: Journal of Consulting and Clinical Psychology, 3, 136-138.

Baker, F. B. (2001). The basics of item response theory (2nd ed.). USA: ERIC Clearinghouse on Assessment and Evaluation.

Bolen, L. M. , Aichinger, K. S. , Hall, C. W. , & Webster, R. E. (1995). A comparison of the performance of cognitively disabled children on the WISC-R and WISC-I1I. Journal of Clinical Psychology, 51, 89-94.

Carlton, M. , & Sapp, G. L. (1997). Comparison of WISC-R and WISC-III scores of urban exceptional students. Psychological Reports, 80, 755-760.

Carnivez, G. L. , & Watkins, M. W. (1998). Long-term stability of the Wechsler Intelligence Scale for Children-Third Edition. Psychological Assessment, 10, 285-291.

Cattell, R. B. (1951). The fate of national intelligence: Test of a thirteen year prediction. Eugenics Review, 42, 136-148.

Edelman, S. (1996). A review of the Wechsler Intelligence Scale for Children-Third Edition (WISC-III). Measurement & Evaluation in Counseling & Development, 28, 219-224.

Flynn, J. R. (1984). The mean IQ of Americans: Massive gains from 1932 to 1978. Psychological Bulletin, 95, 29-51.

Flynn, J. R. (1987). Massive IQ gains in 14 nations: What IQ tests really measure. Psychological Bulletin, 101, 171-191.

10.

Flynn, J. R. (1998). IQ gains over time: Toward finding the causes. In U. Neisser (Ed.), The rising curve: Long-term gains in IQ and related measures. Washington DC: American Psychological Association.

11.

Flynn, J. R. (1999). Searching for justice: The discovery of IQ gains over time. American Psychologist, 54(1), 5-20.

12.

Flynn, J. R. (2001, November). The history of the American mind in the 20th century: A scenario to explain IQ gains over time and a case for the irrelevance of g Paper presented at the Quadrennial Spearman 2001 Conference, Sydney, Australia.

13.

Gaskill III, F. W. , & Brantley, J. C. (1996). Changes in ability and achievement scores over time: Implications for children classified as learning disabled. Journal of Psychoeducational Assessment, 14, 220-228.

14.

Graf, M. H. , & Hinton, R. N. (1994). A 3-year comparison study of WISC-R and WISC-III IQ scores for a sample of special education students. Educational and Psychological Measurement, 14, 128-133.

15.

Kaufman, A. S. (1993). King WISC the Third assumes the throne. Journal of School Psychology, 31, 345-354.

16.

Lynn, R. , & Hampson, S. (1986). The rise of national intelligence: Evidence from Britain, Japan, and the U.S.A. Personality and Individual Differences, 7, 23-32.

17.

Slate, J. R. , & Saarino, D. A. (1995). Differences between WISC-III and WISC-R IQs: A preliminary investigation. Journal of Psychoeducational Assessment, 13, 340-346.

18.

Spitz, H. H. (1989). Variations in Wechsler interscale IQ disparities at different levels of IQ. Intelligence, 13, 157-167.

19.

Stavrou, E. (1990). The long-term stability of WISC-R scores in mildly retarded and learning-disabled children. Psychology in the Schools, 27, 101-110.

20.

Teasdale, T. W. , & Owen, D. R. (1989). Continuing secular increases in intelligence and a stable prevalence of high intelligence levels. Intelligence, 13, 255-262.

21.

Thorndike (1975). Mr. Binet's test 70 years later. Educational Researcher, 4, 3-7.

22.

Truscott, S. D. , & Frank A.J. (2001). Does the Flynn Effect affect IQ scores of students classified as LD? Journal of School Psychology, 39, 319-334.

23.

Truscott, S. D. , Narrett, C. M. , & Smith, S. E. (1994). WISC-R subtest reliability over time: Implications for practice and research. Psychological Reports, 74, 147-156.

24.

Vance, H. Maddux, C. D. , Fuller, G. B. & Awadh, A. M. (1996). A longitudinal comparison of WISC-III and WISC-R scores of special education students. Psychology in the Schools, 33, 113-118.

25.

Wechsler, D. (1974). Manual for the Wechsler Intelligence Scale for Children-Revised. New York: The Psychological Corporation.

26.

Wechsler, D. (1991). Manual for the Wechsler Intelligence Scale for Children-Third Edition. New York: The Psychological Corporation.

27.

Woodcock, R. W. , & Johnson, M. B. (1989, 1990). Woodcock-Johnson Psycho Educational Battery-Revised. Itasca, IL: Riverside.

28.

Woodcock, R. W. , & Johnson, M. B. (2001). Woodcock-Johnson Psycho Educational Battery-III. Itasca, IL: Riverside.