ABSTRACT
As an outsider to the aging business, at least to its study, I am impressed with what has been and can be learned substantively and methodologically from the Seattle Longitudinal Study data base. The objective of Professor Willis’ work — to describe the direction and rate of cognitive change for age differences in various birth cohorts — is significant for increasing our knowledge of the aging process. The various abilities she describes show interesting progressions, asymtotes, and peaks that seek explanation. Gender differences and comparisons at older ages are shown to be related to what has occurred in our society over the past 20 years. Particularly incisive are the findings on inductive reasoning, which we know correlates with school success in younger ages and, as Willis points out, with performance on “right or wrong” answer tests of daily activities in older adults. For this psychometrically defined ability of reasoning, the good news is that the scores of older people of today are up relative to those of older people of years ago; the bad news is that, although the scores of middle-aged people are slightly better than those of the past, they are relatively less so when compared with older people.
