Which side were you on? The Jets or the Sharks? The Capulets or the Montagues? The Greeks or the Trojans? Antony or Caesar? William or Harold? And so the list goes on ... Indeed, maybe the whole of human history is the story of group-making and group-breaking. The passions of loyalty and love for the in-group are matched by the de-humanising indignation and hatred for the out-group.
But what's actually going on in the chemical soup of the brain when Agamemnon gathers his heros-to-be and sets sail after Helen? Will peering into that soup - as neuroscientist David Eagleman is now doing - actually give peace a chance? Maybe utopia can come out of the lab. Will a scientific understanding of love and hate deliver social programmes that undermine the nastiness without sacrificing the good?