Reasoning drill

The complaint that the public no longer trusts experts is, almost without exception, made by experts. That ought to give us pause. It is offered as a diagnosis of the public — a failure of schooling, a symptom of the algorithm, a moral defect in people who will not be told — and almost never as a fact about the profession doing the complaining. But trust is not an attitude the public holds in isolation, like a preference for one colour over another. It is a relationship, and relationships have two parties.

Consider what a reasonably attentive person has watched happen over half a century. Dietary advice reversed itself, then reversed again. Economists who had not seen the crash coming explained it with great fluency afterwards. Each reversal was, in its own terms, the method working exactly as intended: evidence accumulated, conclusions changed. But the public was rarely invited to watch that process. It was handed the conclusions, each one delivered with precisely the same unqualified confidence as the one it had just replaced.

None of this makes the sceptics right. A man who disregards his cardiologist because the food pyramid was wrong in 1985 is committing an error of reasoning so gross it hardly merits the name. But it is a comprehensible error, and treating it as simple stupidity is both inaccurate and — as a strategy for restoring anybody's trust — spectacularly self-defeating.