The need for an environment conducive to achievement for diverse learners is especially challenging at the middle and high school levels, where more students with learning challenges are included in the general education program, but teachers tend to be less tolerant of disruptive and distractible behaviors. Thus, students who do not conform to the behavioral expectations of the general classroom are often removed from the classroom through suspension or expulsion, or are placed in more restrictive school environments for students with emotional and behavioral disorder (EBD), where emphasis is often less on academic learning and more on controlling inappropriate behavior. Underlying the challenges of effective classroom management at the middle and secondary levels, especially for novice teachers, is an ethos of punishment. Teachers embrace punishment because it is easy to administer, it works for many students who have occasional minor misbehaviors, and it is highly reinforcing to teachers. However, punishment does little to teach students self-control and responsibility, and it often leads to a cycle of misbehavior and reaction, resulting in continual power struggles. How, then, can novice and experienced teachers more effectively manage student behavior using positive techniques that enhance the learning of diverse students in middle and high school? What kind of "managers" do adolescents really need? This paper identifies four manager qualities or dispositions of teachers that the authors believe are essential to successful student achievement in middle and high schools: (1) Teachers who make a regular and focused effort to know their students as individuals and who care about their well-being; (2) Teachers who understand how to communicate with adolescents and who are appropriately assertive; (3) Teachers who understand that different strategies must be used with different students depending on individual needs; and (4) Teachers who are committed to culturally responsive classroom management. When novice and experienced teachers enter classrooms with a solid background in management techniques and the dispositional qualities that enhance their ability to successfully manage classroom environments, they will be far more effective in creating a learning climate that maximizes student achievement. (Contains 4 tables.