The purpose of this study is to understand the fundamental reasons enhancing elementary school teachers to accept, or not, the use of differentiated pedagogy in the classroom. A derivative model of Ajzen's planned behaviour theory is tested, upon a sample of 111 Tours-city teachers, with applying a structural equation modeling technique (causal path analysis using maximum likelihood estimates). It combines four psychological determinants of the use of differentiated pedagogy: perception of difficulties, beliefs in norms, behavioural beliefs, and global attitude towards behaviour. This model is adjusted exactly to data. Global attitude has the most important impact on behaviour, perception of difficulties follows next, behaviour beliefs come after, and finally it is followed by beliefs in norms. Perception of difficulties influences all the models' variables. Beliefs in norms have an impact on behavioural beliefs. These two components have an indirect effect on behaviour through global attitude.