In taking a position on an issue, most of us like to think that we accumulate evidence, consider the pros and cons, and then rationally come to a view that we’ll be willing to change if and when the evidence demands it. But it turns out that this is very much a minority way of going about things. The psychological evidence is very clear. What most people do is take a position very soon after being presented with an issue, and then accumulate evidence and reasoning to justify that position. This goes some way to explaining the increasing polarisation of views about coronavirus, which have been hardening over the last few weeks. In one camp we have the government, their scientific advisors, and a large section of the population who reasonably trusted statements from authorities early on in the epidemic.