Ds is 3 and so often I see him act before thinking it through at all. eg we were at a gym thing yesterday and the children were taking it in turns to walk up a bench and jump off the end onto a crash mat. He took turns well and waited til the previous child got off the mat before jumping, but at one point a girl was taking a bit longer to jump and he gave her a nudge off the end. It was a low jump onto a soft mat so no harm done, but I told him off for spoiling her turn. He clearly just found the urge to act too irrestistable.