The behavior, attitudes, and social class of 48 Negro mothers and 48 Negro fathers were related to the development of their fifth grade boys' flexible thinking, defined as the ability to consider alternative means to a given end. The parents were interviewed at home and asked to teach their sons four tasks. Linear relationships were found linking flexible thinking with mother commands, father love, father total words, social class, and two father factors, "powerlessness versus powerfulness" and "rigid, absolute versus warm, sympathetic standards." Quadratic relationships were found linking flexible thinking with mother manipulation, mother commands, mother pointing, father manipulation, and three father factors, "active versus ignoring role with children,""discouraging versus tolerating physical aggression in children," and "powerlessness versus powerfulness." (Author/JS)