The United States takes a hard-line on first cousins marrying. According to Keeping Marriage in the Family it is prohibited in 24 states and restricted to couples unable to reproduce in a handful of other states.
Potential genetic problems with any resultant offspring is the most often cited practical reason why such pairings are not desirable.
"Perhaps the most pervasive, and unmerited, argument regarding cousin marriages is that the children born to such couples will have mental or physical disabilities, which become a burden on society in terms of tax dollars," says CousinCouples.
"The facts show that first cousins have the same increased risk of having a baby with birth defects as a woman over 30 or 35."
My cousin, my love - which states that "Britain has an established tradition of cousin couples ... Traditionally they married to keep wealth in the family" - reports that "the chance of a child inheriting genetic disorders rises from around 2 per cent in the general population to 4% if the parents are cousins. In other words, cousins have a 96 per cent chance of producing a normal baby."
But even the experts disagree about the significance of this. In Row over health risk to cousins who marry it was reported that scientists and health experts were to meet to discuss "the controversial subject of marriages between cousins and their impact on health in Britain." Some researchers say "inter-cousin unions ... have led to a striking rise in the incidence of rare recessive disorders" while others believe the increased risk of birth defects lies within reasonable limits.
Attitudinally, the continued disapproval towards cousin couples seems out of step with our increasingly liberal outlooks on other once frowned upon relationships. When considered in light of growing widespread acceptance of, for example, gay marriage, any reluctance to afford loved-up cousins a similar respect seems ill-considered and hypocritical.
What's your view on cousins marrying? If you disapprove, what exactly is your concern with such a relationship? And, if you have married your cousin, have your faced any strange reactions from others?