How your body language affects your confidence

I've increasingly noticed that a teacher's body language can really impact on the quality of lessons that I have observed. I remember picking up tips from my training mentor years ago on using body language effectively to manage behaviour in class, for example, standing really close to misbehaving students and simply carrying on talking will often reduce low-level disruption. Much of that innate knowledge that experienced teachers have takes time for new teachers to pick up. Here's a useful TED talk from social psychologist Amy Cuddy on the use of "power posing" to build confidence.