A longitudinal study of an initial sample of 300 men whose ages ranged from 24 to 87 years was
carried out using modifications of the logical problems devised by Johns. Cross-sectional results
for all problems showed that, with increasing age, proportions of subjects who solved decreased
and uninformative inputs increased. The mean interval between first and second measures was
6.7 years. Longitudinal measures of changes showed a mean decline in performance only for the
group which was over 70 initially. Much of the decline was attributable to redundant inputs
despite the fact that memory demands were minimized and the entire record of input-outcome
events was always available. Six-year survival also was related to successful problem-solving in
the first session.
Alan Zonderman abz@lpc.grc.nia.nih.gov
Laboratory of Personality & Cognition, National Institute on Aging, NIH
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