British Educational Research Journal. Vol. 13, No. 2, 1987 121 Constructivism in the Classroom: enabling conceptual change by words and deeds MIKE WATTS & DI BENTLEY, Secondary Science Curriculum Review Introduction This paper follows a thread of argument that can be summarised as follows: (a) a major element of science education concerns enabling youngsters' concep- tual change; (b) current theories of conceptual change require considerable self-exposure by youngsters' of their existing ideas; (c) willingness to articulate and explore personal theories is dependent upon the learning environment that prevails in a classroom; (d) the learning environment is created both by what a teacher says and the way that he or she behaves; (e) youngsters are shrewd judges of behaviours which indicate trust, sympathy and empathy in teachers and prefer to work for and learn with teachers they trust; (0 effective conceptual change requires that teachers become skilled in both the verbal and the non-verbal cues they initiate. The thread through the arguments is an attempt to bring together two distinctive and often separate research domains: cognitive development on the one hand, and non-verbal behaviour on the other. Within the paper we explore aspects of what we call a 'non-threatening learning environment' (NTLE). At first glance it might seem a mildly eccentric inconsequence—rare are they who champion a threatening learning environment. It seems to us. however, a notion worth developing on two counts. The first relates to communicative acts within the psychosocial atmospheres of school classrooms, whilst the second stems from recent research work and curriculum development in terms of cognitive structures and conceptual change. We develop our notional NTLE largely against a curriculum backdrop of school science education and from interview data as youngsters interpret teachers' postures and gestures. Our experiences foster the conviction that, on the whole, life in school classrooms is conducted in a fairly robust atmosphere, redolent of the normal chiding, teasing