Debating ethical issues is a key part of the new 21st-century science GCSE.
It is a high-level skill for pupils to think from someone else's perspective and scrutinise ideas, so I use the idea of "box heads".
Three boxes have faces drawn on them: one smiling, one frowning and one questioning. Three pupils put these on their heads. The smiling one must agree with a particular idea, and the frowning one disagree, giving reasons for their positions. The one with the questioning face must query the evidence. Other pupils can also contribute to the discussion. The pupils wearing the boxes then choose which pupil to hand their box on to. Less confident children thus have a structured way to contribute to the debate and cover their blushes
Laura Seabright is a teacher at Addey and Stanhope School, Lewisham, London