category of behavior was computed using the Pearson product-moment correlation. These correlations ranged from .92 for duration of time proximal to mother to .98 for duration of play. As in the earlier laboratory study, behavior in the home was a function of the adult with whom the infant was left, F (2, 36) = 18.2, p < .001 for play; F (2, 36) = 5.5, p < .007 for crying; F (2, 36) = 18.1, p < .001 for proximity to door. Infants played significantly less during the two 3-minute periods when left alone with the stranger than during the two conditions when left alone with either mother, q (1, 36) = 23.9, p < .01, or father, q (2, 36) = 27.3, p < .01. There was no significant difference in play when the child was alone with the mother or father. Infants also cried significantly more when left alone with the stranger than with mother, q (2, 36) = 13.8, p < .01, or father, q (1, 36) = 9.0, p < .01, but duration of crying was similar when the child was alone with either parent. Finally, children remained near the exit longer during the two conditions when alone with the stranger than during the two conditions when alone with either father, q (2, 36) = 22.4, p < .01, or mother, q(l, 36) = 19.6,p < .01. There was no significant difference between mother or father. Although infants in both home and laboratory were maximally upset by being left alone with stranger but minimally upset when left alone with either parent, there was significantly less distress in the home than in the unfamiliar laboratory situation as revealed by the Context X Person interaction for crying under conditions when the child was alone, F (2, 72) = 10.0, p < .001. Children tested in the laboratory cried almost three times as long as those tested at home during the two conditions when they were left alone with the stranger, F(l, 72) = 8.9, p < .005. Context did not influence crying when the child was alone with either mother or father. The greater distress in the laboratory was also reflected in the significant Context X Person interaction for change in duration of play for the conditions following adult departures, F (2, 72) = 6,4, p < .003. Playing decreased twice as much in the two periods following the mother's departure in the laboratory than at home, F(l, 72) = 6.7, p < .02,