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…

SEVERAL EXPERIMENTS ON THE CONCEPTUAL BEHAVIOR OF LOWER AND MIDDLE CLASS CHILDREN ARE DESCRIBED IN AN EFFORT TO CLARIFY AN APPARENT DISCREPANCY BETWEEN PREVIOUS LABORATORY FINDINGS AND OBSERVED CLASSROOM PERFORMANCE. IN THE FIRST EXPERIMENT, INDUCTIVE CONCEPT LEARNING WAS INVESTIGATED AS A FUNCTION OF SOCIAL CLASS MEMBERSHIP AND PRIOR EXPERIENCE.…