Aging, attention, and intelligence.
The aims of this study were (a) to find out if attentional ability factors that are separate from the well-established ability factors (e.g., fluid intelligence, crystallized intelligence, and short-term acquisition and retrieval function) can be identified, and (b) to establish, through the use of part correlations, whether attentional abilities play a role in the changes in fluid and crystallized intelligence that occur with increasing age. A battery of 36 tests (19 psychometric tests and 17 measures of attentional processes) were given to 100 people. 20 of whom were in each age decade between 20 and 70. Results indicated that three attentional factors--Search, Concentration, and Attentional Flexibility--exist at the primary-ability level and that all three define fluid intelligence at the second-order level. Results also indicate that the decline in fluid intelligence with increasing age disappears if attentional factors are parted-out. Similarly, the increase in crystallized intelligence with increasing age becomes even greater if one controls for attentional processes. I conclude that changes in attentional processes play an important part in changes in human intelligence with age.