Subjects were examined with a battery of protocols based on principles of experimental psychology and designed to measure motor control, perceptual-motor coordination, attention, learning, and memory. Differences between index and control subjects were found on the mirror-drawing protocol, reflecting visual-motor coordination, and the distractibility protocol, in which subjects divided their attention between verbal and visual stimuli. There were no differences in subjects due to conditions of rearing, and no interactions. Differences between index and control children were subtle, and tended not to appear on simpler tasks. The stage of processing leading to poor performance by the index children awaits further study for elucidation.