Summary
In three different groups of boys boundary definiteness was related to the effectiveness of the boys' classroom behavior. In emotionally disturbed boys it was correlated with the teachers' reports of how much difficulty the child had in adjusting to the classroom. In normal fifth and sixth graders, it was correlated positively with teachers' ratings of classroom effectiveness. Teacher ratings of maturity behavior of the group of first grade boys was also significantly related to boundary definiteness. The results indicate that boundary definiteness is a significant generalized predictor of classroom behavior. The boy who has a clear sense of his boundaries and his demarcation from others behaves effectively in the school environment.