This paper focuses on the relationship between rational beliefs, culture and agency in formal school settings. This relationship is analysed in the context of the adoption of technological innovations. Interviews and focus groups with 39 secondary teachers from England and other European countries were carried out. The analysis highlights a number of cultural differences between English teachers and their continental colleagues. The paper argues against a linear and simplistic appropriation of rational choice theory in educational research, whereby individual behaviour is examined from the perspective of individualist psychology and micro-economic theory without considering models of culturally informed agency beyond self-interest and calculation. In the conclusion, the paper argues that explanations of teacher agency in relation to technology must take into account the role of rationality and emotionality--not as a binary opposition that reflects actual psychological qualities that teachers may or may not possess, but as phenomena to be unpacked: competing (and culturally shaped) discursive strategies enacted to make sense of the world.