Psychology and Aging 1988, Vol. 3, No. 1,29-37 Copyright 1988 by the American Psychological Associations Inc. 0882-7974/88/$00.75 Investigation of Student Status, Background Variables, and Feasibility of Standard Tasks in Cognitive Aging Research Timothy A. Salthouse, Donald Kausler, and J. Scott Saults University of Missouri—Columbia Data are reported on a variety of cognitive tasks from 62 college students and 362 nonstudent adults between 20 and 79 years of age. The goals of the project were as follows: (a) to investigate the validity of the practices of using college students and adults over age 65 in studies of cognitive aging, (b) to examine the influence of a variety of background variables on age trends in cognitive performance, and (c) to initiate the development of standard tasks to assist in the description of subject samples in cognitive aging research. The age trends in cognitive performance were relatively independent of an assortment of background variables, but because college students were atypical of their age group in several performance measures they may be suspect as the young-adult control subjects in investiga- tions involving these types of measures. Adults over the age of about 65 appear to exhibit accelerated slowing of speeded performance, but in other respects perform about as one would expect on the basis of the age trends observed between the ages of 20 and 65. The present studies were designed to investigate three issues considered important in research on cognitive aging. Two of the issues were related to the assessment of presumably normative cross-sectional age trends in cognitive functioning (student sta- tus of young subjects and the role of background variables on the relation between age and performance), and the third (stan- dard tasks) was concerned with improving the description of subject samples in cognitive aging research. One focus of the current studies was to examine the validity of the practices of using certain subject populations in research on cognitive aging. Specifically, college students were investi- gated because of the possibility that participation in school-re- lated activities might provide them with an advantage in some cognitive tasks, and adults over age 65 were investigated because of the possibility that factors of retirement-associated activity disengagement and increased susceptibility to many diseases may lead to exaggerations of age-related effects on cognition. The means of investigation involved determining whether the performance of college students or adults over age 65 is predict- able from the regression equations relating age to performance among nonstudent adults ranging in age from 20 to 65 years. If not, and the performance of college students or adults older than 65 is discontinuous from the functions of nonstudents of varying ages, then it might be inferred (a) that college students are not appropriate young-adult control subjects in studies de- signed to assess the effects of age on that type of cognitive func- tioning, or (b) that age-related effects beyond about age 65 in- volve somewhat different processes than those occurring at younger ages. A second focus of the current studies was to determine the contribution of variables related to the individual's status or This research was supported by a grant from the University of Mis- souri Weldon Spring Research Fund. Correspondence concerning this article should be addressed to Timo- thy A. Salthouse, who is now at the School of Psychology, Georgia Insti- tute of Technology, Atlanta, Georgia 30332. background (e.g., years of education; self-reported health; occu- pational status; and average number of hours per week spent reading, watching television, etc.) to observed age trends on measures of cognitive performance. Many of these variables are significantly related to age, and it is sometimes suggested that they might be responsible for the age trends frequently reported in various measures of cognitive functioning. We investigated this possibility by determining whether the correlations be- tween age and cognitive performance are significantly altered by statistically controlling for these background variables. The third and final goal of the current research was to initiate the development of standard tasks that might assist in describ- ing and assessing the comparability of samples of participants in research on cognitive aging. A currently accepted practice in published studies in the area of cognitive aging is to report, in addition to ages of the participants, information about their de- mographic characteristics (e.g., average years of education) and summary statistics about their performance on certain psycho- metric tests (e.g., vocabulary or general information). This in- formation is presumably provided for the purpose of describing relevant characteristics of the samples, but because there is sel- dom any evidence that these variables are related to perfor- mance on the task of interest, it is questionable whether such information can actually be used to assess the comparability of the samples for the experimental task being investigated. It is useful to think of a continuum representing the purposes of information, other than performance on the tasks of primary interest, obtained from participants in studies of cognitive aging. At one end of the continuum is information simply in- tended to reflect the individual's global status. For example, noninstitutionalized living and ability to transport oneself to the research laboratory are sometimes considered indexes of relatively unimpaired functioning. At the other end of the con- tinuum is information obtained for the purpose of statistical analysis in conjunction with the age and performance variables. That is, partial correlation or analysis of covariance techniques might be used to investigate the extent to which certain vari- 29 This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly.