FEW ideas from social psychology have captured public attention in recent years as much as unconscious bias, the catch-all term for the assumptions we make about other people without being consciously aware of the process.

That reach is partly down to the Implicit Association Test (IAT) created by researchers at Harvard University in the 1990s. Available online, it is widely seen as a quick and easy way to see how implicitly biased you are. The results can be unsettling: you may not think you are racist or sexist or ageist, but, in many cases, your unconscious preferences, …