Brooke Magnanti, better known by her nom de plume Belle du Jour, is a biologist, blogger and author, who rose to fame following the publication of her 2005 book Intimate Adventures of a London Call Girl, later adapted for television. Below, she discusses whether love is an artificial construct and if people should be allowed to marry their first cousins.

There have been suggestions that love is a modern invention. Do you think that love is intrinsic to the human condition or in some way artificial?

I think we have exaggerated certain aspects of love, especially romantic love, what we expect it to be and expect it to become: this idea of fidelity and two people loving each other forever. Yet we can't deny that there is a biological underpinning to all of it.

In the initial stages of