Last week, the National Health Service (NHS) England Genomics Education Programme published guidance that appeared to endorse the benefits of first-cousin marriages. Research into first-cousin marriage describes various potential benefits, including stronger extended family support systems and economic advantages (resources, property and inheritance can be consolidated rather than diluted across households). Catholics banned first cousin marriage in the sixth century and second cousin marriage in the 14th century. In parts of rural Pakistan 80% of people are the products of cousin marriages. “The Conservatives want to see an end to cousin marriage as a backdoor to immigration too, but Labour are deaf to these sensible demands.