The study of children's group formation employs Piaget's cognitive-development theory along with ethological concepts and methods used in the naturalistic study of the social behavior of animals. It represents the first application of ethological ideal to a study of the child's conception of his social world, and focuses on his conceptions of the dominance relations within the class, and the effect his perceptions of others have on his behavior when interacting with classmates. Subjects were 500 public school children, aged three to nine. Preliminary results seem to indicate the usefulness of integrating Piaget's work in development with ethological ideas of adaptation. (Author)