A cross-sectional study that investigated memory variables in 100 subjects in 4 age ranges (17-22, 40-50, 60-70, and 75-99) found that the 60-70 year olds were more impaired with respect to retrieval than storage and the major problem with memory among the 75-99 year olds was retrieval from short- or long-term memory. Because the study was…

The study sought to use Jensen's two-level theory of mental abilities to predict some hitherto unknown or unnoticed phenomena--facts about which the theory should yield clear-cut predictions and which are not as clearly predictable from other theories, though they may receive ad hoc explanations after the fact. From the two-level theory of mental…