U.S. Supreme Court justices and other federal judges are, effectively, appointed for life, with no built-in check on their cognitive functioning as they approach old age. There is about a century of research on aging and intelligence that shows the vulnerability of processing speed, fluid reasoning, visual-spatial processing, and working memory to…

In surveying the literature on assessment of cognitive abilities in adults and children, it is easy to assume that the proliferation of test batteries and terminology reflects a poverty of unifying models. However, the lack of recognition accorded good models of cognitive abilities may reflect inattention to theoretical development and injudicious…

According to the most widely accepted Cattell-Horn-Carroll (CHC) model of intelligence measurement, each subtest score of the Wechsler Intelligence Scale for Adults (3rd ed.; WAIS-III) should reflect both 1st- and 2nd-order factors (i.e., 4 or 5 broad abilities and 1 general factor). To disentangle the contribution of each factor, we applied a…