The primary purpose of this study was to examine differences in performance on fluid and crystallized intelligence tasks as a function of age and fitness. A secondary purpose was to examine the influence of age and fitness on the beneficial effects that practice has on both performance and retention on these tasks. Fitness was assessed in 41 older and 42 younger participants who were then randomly assigned to either experimental or control conditions. Participants performed repeated trials on two cognitive tasks during acquisition and retention, with the experimental group practicing for 100 trials and the control group practicing for 20 trials. Older participants performed better than younger participants on the crystallized intelligence task: however, younger participants performed better than older participants on the fluid intelligence task. On the fluid intelligence task, older fit participants performed better than older unfit participants. Learning did occur on the fluid task and differed as a function of age and fitness. Learning did not occur on the crystallized task.
Jennifer L. Etnier was with Arizona State University at the lime of the study and is now with the Health and Exercise Science Department, Wake Forest University, P.O. Box 7868, Reynolda Station, Winston-Salem, NC 27109. Daniel M. Landers is with the Department of Exercise Science and Physical Education, Arizona Stale University, Tempe, AZ 85282.