You're onto something important, but I'd offer a different interpretation. All 'effects' -- the sense of being watched, the activation of prior viewpoints -- ar

You're onto something important, but I'd offer a different interpretation. All 'effects' -- the sense of being watched, the activation of prior viewpoints -- are downstream of treatment. Theoretically, the kids who were randomly assigned to the control group had the same biases (in expectation), so all observed effects can be attributed to watching the documentary.