Lower class black and lower class white first-grade children learned an unorganized and an organized list of words to test Jensen's hypothesis of racial differences in mental abilities. Both groups of children performed significantly better on the organized list with comparable means for each list. Most of the predicted relationships were not…

A study was made to determine how the rate of spelling and the retention of spelling words was influenced by the number and spacing of practice presentations on unlearned words. Sixth-grade students (42) in East Palo Alto were drilled by a computer for 6 weeks on six lists of 12 different spelling words each. They drilled on one list until (1)…

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…