Disadvantaged children may seem restless and lost when presented with middle-class play materials. One generally attributes poor play habits to such prior home experiences as lack of maternal social reinforcement for sustained play, interruptions from other children or adults, or damaged play materials. However, no controlled research has been done concerning the effects of analogous experimental conditions on subsequent play persistence. In the present experiment, 56 black 5year-old girls were obtained from Ready Fives and kindergarten programs, and were randomly assigned to one of four 10-minute treatments. Neutral. Children were permitted to play freely with puzzle, bubble liquid and wand, playdough, magic slate, paints, a whistle, and a book. Defective. Children played freely with exactly the same toys, except that toys had been doctored. The puzzle pieces were the right colors, but the wrong shapes; the playdough was crumbly (it had been baked); there was not enough bubble liquid to fill the wand; the magic slate had been painted with clear nail polish so the stylus made no impression; the paints were dried, and the brush was matted; the whistle no longer tweeted; critical pages were torn out of the book. Interruption. Children played with good toys, but were constantly interrupted by the 1 An extended report of this study may be obtained without charge from S. Farnham-Diggo ry,