Writing recently at edge.org , one of the founding fathers of evolutionary psychology, John Tooby, answered a question which had long baffled me. Why do people on the left get more agitated about transgender bathroom access or hate speech than they do about modern slavery? Tooby explains: ‘Morally wrong-footing rivals is one point of ideology, and once everyone agrees on something (slavery is wrong) it ceases to be a significant moral issue because it no longer shows local rivals in a bad light. Many argue that there are more slaves in the world today than in the 19th century. Yet because one’s political rivals cannot be delegitimised by being on the wrong side of slavery, few care to be active abolitionists any more, compared to being, say, speech police.’ I might also add that many of the practitioners of modern slavery might be a bit foreign–looking, and so in criticising them you run the risk of violating some leftist tribal shibboleth.