What Halloween teaches about the body in costume.

There's a term in theatre for this: the character emerging through the body before the mind fully commits. Konstantin Stanislavski called it physical action — the idea that emotion follows from the body's doing, not the other way around. We tend to think: I feel frightened, so I tense up. The actor's knowledge is that this works in reverse. Tense up deliberately and the feeling that fits the tension begins to arrive.

Children who dress up for Halloween, or for any costume occasion, are doing something that child development researchers have been interested in for decades. It's not play-acting. It's identity exploration through physical transformation. The costume changes what's available — what posture is accessible, what voice, what speed of movement. The child who is shy in their own clothes may find that the knight's armour produces a different kind of confidence, because confidence is partly postural and the costume has already handled the posture.

I watched my daughter walk to the refrigerator in the witch costume and I watched her decide, in real time, that she wanted juice differently than she would have wanted it as herself. The witch was slightly imperious about the juice. My daughter thought this was very funny. The humour is part of it: the distance from the self is safe, and safe distance is where children try things they wouldn't try as themselves.