There are grounds for both great optimism and a healthy dose of pessimism in assessing the impact of theories of development and learning on today's pedagogy and education. On one hand, mainstream practices and lay concepts, to a large extent, are still entangled in mechanistic notions derived from the orthodox cognitivism with its notions of knowledge as representation of information stored ‘in the head’ (to be retrieved upon demand) and of thinking as an entirely internal process of symbol manipulation occurring in isolation from the real world and human engagement in it. Associated conceptions of teaching and learning still focus on the top-down transmission of information, entailing essentially the passive role of students as being mere recipients of knowledge and that of teachers as being mere conveyors of this information.