Fluid intelligence performance in the elderly: Intraindividual variability and conditions of assessment.

Abstract

The study of performance factors plays an increasingly salient role in understanding the range of intraindividual variability (plasticity) in intellectual aging. Among performance factors considered are aspects of the testing situation. Two studies are reported that examine intraindividual variability in performance on measures of fluid intelligence (figural relations, induction), varying either practice (retesting) or testing time (standard vs. power) conditions. Subjects are elderly community residents (mean age: 70.6 years; range: 60-84 years). Substantial improvement in level of correct performance (with no evidence for changes in test validity) is obtained for both retest and power conditions. Error patterns, however, differ for the two conditions, with a higher proportion of commission errors occurring under power conditions. Results are interpreted as contributing to the position (a) that older persons continue to show learning capacity and (b) that studying the range of performance under varying conditions is critical to an understanding of intellectual aging.A major theme in gerontological intelligence research has been the issue of change and variability in intellectual functioning (Baltes & Labouvie, 1973; Botwinick, 1977;Horn, 1978). This research has focused on individual differences, primarily age differences in adult intellectual performance. However, much less attention has been given to the issue of intraindividual variability. Normative or average level of performanceThe first study reported was conducted as part of the first author's master's thesis under the direction of the second and third authors. The research was supported by National Institute of Aging Grant 5 R01 AG00403-03 awarded to Paul B. Baltes and Sherry L. Willis. The study is part of a research program entitled Adult Development and Enrichment Project (ADEPT), examining the effect of cognitive training on older adults' intellectual performance. Thanks are due to project research assistants Rosemary Blieszner, Steven Cornelius, Margie Lachman, and Ron Spiro, field and training staff Carolyn Nesselroade and Myrtle Williams, and John R. Nesselroade and Paul G. Games, statistical consultants.

Everyday Competence in Later Life: Current Status and Future Directions

“…Similarly, training studies in the domain of intelligence (P. Hayslip, Maloy, & Kohl, 1995;Labouvie-Vief & Gonda, 1976) and memory (P. Baltes & Kliegl, 1992;Neely & Backman, 1995;Rebok & Balcerak, 1989;Scogin & Bienias, 1988;Yesavage, Lapp, & Sheikh, 1989) have documented the range of plasticity in intelligence and memory in older adults. In particular, it has been shown that older adults can considerably improve their cognitive functioning through systematic training (P. Hayslip et al, 1995;LabouvieVief & Conda, 1976;Neely & Backman, 1995) and even through repeated practice (Hofland, Willis, & P. Baltes, 1981). Moreover, it has been shown that in healthy, community-residing older adults normal agerelated declines in intellectual functioning can be reversed through systematic training (Schaie & Willis, 1986).…”

On the range of cognitive plasticity in old age as a function of experience: 15 years of intervention research

“…Average educational level (roughly comparable to U.S. information on educational history) was 11 years (SD = 2.7). When comparing level of intellectual performance on equivalent tests with the U.S. samples from rural Pennsylvania (e.g., Hofland et al, 1981), the Berlin sample scored about 0.5 SD higher. The Berlin sample was also slightly more heterogeneous in intellectual performance.…”

“…To investigate this issue more systematically, Hofland, Willis, and Baltes (1981) conducted a study involving eight sessions of self-guided practice with intelligence tests. Two tests were administered, each representing one subability of fluid intelligence: figural relations and induction.…”

Reserve capacity of the elderly in aging-sensitive tests of fluid intelligence: Replication and extension.

“…Average educational level (roughly comparable to U.S. information on educational history) was 11 years (SD = 2.7). When comparing level of intellectual performance on equivalent tests (figural relations, induction) with the U.S. samples from rural Pennsylvania (e.g., Hofland et al, 1981), the Berlin sample scored about 0.5 SD higher. In terms of interindividual variability, the Berlin sample was also slightly more heterogeneous.…”

“…Level of difficulty and accuracy were considered for this purpose. For example, it could be that trained subjects may have improved exclusively on items that were relatively easy, or that they simply tried to answer more items than did control subjects, thereby benefitting from guessing (Hofland et al, 1981).…”