We've all been single and wondered if we'd ever find someone. Hands up who thought about dating their cousin? In the UK it is legal to marry your cousin; in parts of West Africa there's a saying, "Cousins are made for cousins"; but in America it is banned or restricted in 31 states. Restrictions include genetic counselling or that couples are past the age of reproduction.

I've never lusted after my cousins, and I'm confident the feeling is mutual. My cousins are people I've known from childhood; I've been bathed with them and we've accompanied each other to weddings and funerals. Not as close as a brother, but close enough, thanks.

The actor Greta Scacchi encountered small-minded attitudes similar to mine when she married her first cousin Carlo Mantegazza. "People were scandalised," she said, "but it is perfectly legal. I was really upset at all the fuss, but I came through it – we both did – and we are very happy." The American website cousincouples.com is full of couples too scared to tell their parents they are "kissing cousins". It also attracts comments: "Here you all are flaunting your incestuous ways… I bet $10,000 that you all smell like polecats and are too socially backward to get real dates."

Last year the environment minister Phil Woolas caused a row by attributing the higher than average rate of genetic birth problems in the Pakistani community to their practice (around 55% of marriages) of marrying first cousins. He told the Sunday Times, "If you have a child with your cousin, the likelihood is there'll be a genetic problem."

Supporters of marriage between cousins (or just people who care about truth) cried foul and cited findings from a panel published in the Journal of Genetic Counselling (based on studies of thousands of births over 35 years) showing risks of between 1.7% and 2.8% above the background risk for congenital or genetic abnormalities (which meant a doubling of what is still quite a small risk for having a condition such as cystic fibrosis or spina bifida).

Martin Ottenheimer, an American anthropologist, has long argued against the US ban on cousin marriages. "The ban is due to a deep-seated prejudice, an expression of stereotype," he says. "Humans have to define closeness, who is too close to marry. But if that closeness is decided on the basis of wrongly interpreted genetics, then it is not justified.

"It is not unusual, especially for elderly couples, to feel comfortable with and be attracted to their cousins. To say they shouldn't marry if they fall in love is unfair."

But as cousincouples.com points out, unlike with other relationships, if things don't work out, you'll still be cousins for the rest of your life.