Over the years, scientists have proposed various theories about why humans cooperate so well that we form strong societies. The evolutionary roots of our general niceness, most researchers now believe, can be found in the individual survival advantage humans experience when we cooperate as a group. I’ve come to New Haven, Connecticut, in a snowy February, to visit a cluster of labs where researchers are using experiments to explore further our extraordinary impulse to be nice to others even at our own expense.

we seem to be reverting to tribalism and conflict, and belief in the potential of the internet to bring humanity together in a glorious collaborating network now begins to seem naive.

But this has a consequence of favouring divisive and strongly emotive or extreme content, which can in turn nurture online “bubbles” of groups who reflect and reinforce each other’s opinions, helping propel the spread of more extreme content and providing a niche for “fake news”.

A survey last year found that 40 percent of American adults had personally experienced online abuse, with almost half of them receiving severe forms of harassment, including physical threats and stalking.

On the evening of 17 February 2018, Professor Mary Beard posted on Twitter a photograph of herself crying.