Salthouse on aging/intelligence paradox

"An intriguing discrepancy exists between the competencies of older adults, assumed on the basis of everyday observations, on the one hand, and their competencies inferred from laboratory results, on the other hand. The laboratory results tend to portray older adults as distinctly inferior to young adults on a number of presumably basic cognitive abilities, and yet we are all aware of competent, and even remarkable, accomplishments of people well into their 60s, 70s, and beyond. One is thus faced with the question of how to account for this apparent discrepancy between the rather pessimistic results of the laboratory and the more encouraging observations of daily life. (Salthouse 1987, p. 142)"