It is usually seen as a depressing paradox about human beings that we find it easier to sympathise with one person’s suffering than with that of thousands: Stalin probably never really said “one death is a tragedy, a million deaths is a statistic” – but he was right all the same. It’s not much of a paradox, though. It makes sense: each of us has access to only one set of thoughts and emotions – our own – so we’re obliged to relate to others by analogy, working on the assumption that they feel pain and joy like we do. (As philosophers enjoy pointing out, you can’t truly know that your family and friends aren’t just meaty robots, with no inner life at all.) And it’s obviously easier to draw an analogy between yourself and one other person, as opposed to “the population of Somalia” or “all victims of domestic violence”, let alone those killed in the future by global warming, who aren’t necessarily even born yet. Empathy requires mental gymnastics at the best of times. Empathy for whole categories of people requires Olympic-level skills, and most of us aren’t up to it.

But there’s an intriguingly easy way to induce compassion for groups, according to a new study by the psychologist Kurt Gray and colleagues, published in the Journal Of Experimental Psychology and reported by Vox. It makes a difference, they found, whether you say “a group of 50 refugees” (for example) versus “50 refugees in a group”. The first phrasing focuses on the group, not its members, with the result that we think of those members as less capable of rich inner experience – and less human, if we’re honest – than ourselves. The latter phrasing focuses on the members, rather than the group. That linguistic switch proved sufficient for participants in the study to treat them as fully human, and fully deserving of compassion.

There’s always a risk, with research like this, of concluding that the problem at hand – in this case, people treating other groups of people as less human – is simply a matter of language. Change how we talk, then watch racism, bigotry and insular nationalism evaporate! But the real point is that language offers a clue to why such sentiments arise: because of a failure to fully imagine the inner lives of others. Which is a cause for optimism, actually. After all, wouldn’t it be worse if people were racist because they had fully imagined the emotional lives of members of other races, yet still didn’t care about their unjust treatment? Whereas if bigotry is a failure of imagination, it’s less a matter of people being awful and more of their being somehow mistaken. Which means there’s at least a chance of correcting the error.

It’s also a reminder that prejudice needn’t arise from some inner kernel of badness that only certain people – “the bigots” – possess. We all face the challenge of drawing analogies between our inner lives and others’, and we could all potentially screw it up. The problem isn’t so much hating other people, exactly, as not totally appreciating that they are other people to begin with.

oliver.burkeman@theguardian.com