How Gay Became OK

Why have British attitudes towards homosexuality changed so far and so fast? Less than 50 years ago, sex between men was a criminal act. Now they can marry. It's not just the law that has changed: we have. Surveys suggest that public opinion about homosexuality has undergone a dramatic shift over the same period. Jo Fidgen asks what drives this kind of change in collective attitudes. Producer: Chloe Hadjimatheou.