Puberty is associated with a period of psychological change concomitant with structural changes in the brain, particularly that of the prefrontal cortex. Recent evidence suggests an endocrinological relationship. In the context of education, the effect of these biopsychological changes on executive function, particularly social cognitive ability and that of behavioural responses to challenges in the school environment, is of particular interest to teachers, who are required to manage behaviour in the classroom, school leaders who devise behaviour management strategies and those in government who decide on policy. In this dissertation, potential associations were explored between plasma concentrations of cortisol and testosterone, physical development, psychological difficulties, social cognitive function and the behaviour of adolescent boys aged between 11 and 16 in the school context. It was conducted through the quantitative analysis of secondary data taken from the United Kingdom’s Avon Longitudinal Study of Parents and Children (ALSPAC) followed by a case study approach for extreme biopsychological outlier cases in the secondary school setting. The research outcomes were not supportive of hypotheses that associate poor psychosocial outcomes with biological data in the general population. However, strong associations exist between biological measures, psychosocial problems and the behaviour of a small number of individuals with extreme biological and psychological values. It was evident that some schools engage in exclusionary practices that may go against Government policy and may even be illegal. It is hoped that dissemination of the project findings and the recommended behaviour interventions will help schools to improve the inclusion and achievement of boys with challenging behaviour.