INTRODUCTIONTo UNDERSTAND adult social behaviour we must know something of its development. Por the child, an important phase in the development of his social relations is the shift from the small circle of his family to the wider horizons of school and peer groups. This phase may be conveniently studied in a nursery school, which, for many children, represents their first encounter with a large group of like-aged children.The description and analysis of social behaviour in nursery schools was one of the dominant themes iti American child psychology in the 192O's and 193O's. Though some of the work was marred by a preoccupation with the nature-nurture pseudoquestion and naive motivational assumptions, much valuable descriptive work was achieved before the tradition was lost in the 194O's. Two of the reasons for this demise are pointed out in a perceptive and prophetic essay by Lawrence Frank in a volume that serves as a fitting memorial to the era (Barker, Kounin and Wright, 1943). "The skill and ingenuity that have been displayed in the construction and refinement of these instruments [I.Q,. tests] should be emphasized because at times it appeared that the interest of child psychologists was so absorbed in this occupation that it precluded much concern for or curiosity about the children themselves . . .[this] threatened to arrest the further developtnent of child psychology, in so far as other interests and problems not susceptible to psychometric formulation and approach were neglected." Prank was over-optimistic in writing this in the past tense, as he was when he pointed out that "the increasing prestige of the statistical method not only operated to condition the problems which students selected for study" but also produced anomalies which could not "be resolved because so little was known about the child subjects beyond sex and chronological age and the one or two measurements tbat had been obtained". These trends, coupled with the domination o^S~R psychology, killed the tradition.In the last few years we have seen a revival of interest in descriptive studies which may be largely attributed to a few ethologists who have turned their attention from animals to their own species. They are producing detailed descriptions of the expressions, gestures and movements of pre-school children (Blurton Jones, 1967; McGrew, 19G8) which are a necessary element for a successful analysis of social behaviour.The quality and quantity of social interaction is, in part, determined by the situation in which children meet. Por example, several studies have shown that social interaction varies with the occupation chosen by the child (Parten, 1933;Green, 1933} and is more marked in the absence of toys (Johnson, 1935). Restriction of