Real experts know what they don’t know and we should value it.

A small but real part of the problem is that reputational incentives to appear qualified and knowledgeable drive experts to overstate their certainty. One way to counter this tendency is to ask better questions, and that usually means questions about the nature of the evidence and what it allows. We can also change the way that we relate to experts, not just listening to the loudest and most confident voices, but to those with a track record of only claiming as far as the evidence will take them, and a willingness to say ‘I don’t know.’