Since, like so many of my readers, you are highly sexually attractive, would you mind sending me some photos? No, not that sort of thing. I actually meant a map of your genome. ‘I’d like to get into your genes’ is a great line to use on me, by the way, because as a geneticist it really is all I’m interested in. Romance is crushed by the power of the selfish gene.  It’s genes that want candlelit dinners and like that sweater that brings out the colour of your eyes: they want to replicate themselves during sex and can be set free into the world to continue their selfish cycle.

But what about the genetic agenda of your family? According to research published last month by biological anthropology researcher Molly Fox and colleagues at the University of Cambridge, even your grandmother may harbour selfish intentions. Fox suggests that grandmothers are programmed to prefer their sons’ daughters to their sons’ sons. The data, drawn from seven societies around the world from the 17th to the 21st centuries, grimly found “a relationship between X-chromosome inheritance and grandchild mortality in the presence of a grandmother”.  This makes logical selfish-gene sense since her granddaughter’s genes through her son will carry a copy of her X-Chromosome and her grandsons will not.  Other studies have found that ‘love’, measured by action taken to ensure offspring survival, is directly correlated to genetic relatedness. 

Such an absolute correlation is bleak and cannot apply to gay couples, adoptive parents, step-parents and those who choose not to have children. Does it only apply to those with children and paternal grandmothers? What would be interesting but slightly controversial is a study on those with both non-biological and biological children. The true influence of genes on relationships is unclear, although they can occasionally explain why your grandmother knits your sister’s fleece first and why the postman has an unusual interest in your schooling.