Theory and research related to early adolescent sex role development needs to be addressed from both a life-span and an ecological perspective. A study was conducted to examine the development of male early adolescent sex role attitudes and behaviors in an ecological context. Data were the results of a state-wide survey of 10- to 14-year-old males (N=146) and their parents conducted in Michigan in 1983. Youths were interviewed in their homes and parents responded to a questionnaire. Subjects were selected using a stratified multi-stage cluster sampling technique. Hierarchical multiple regression was used to test both early adolescent sex role attitude development and behavior development models. The model for male early adolescent sex role attitudes was significant. The level of traditionalism of male early adolescent sex role attitude development was significantly influenced by the level of traditionalism of the mother's sex role attitudes in interaction with the level of closeness that the son reported feeling about the mother, and the mother's and father's perceptions of their son's pubertal age. The model for male early adolescent sex role behavior was not significant. (Author/NB)