Íslendingabók: How Icelanders Avoid Incest and Find Celebrity Relatives

Living in a small, mostly static population creates some uncomfortable issues. Aside from making it difficult to dodge people you don't like, you also have to worry about whether you're unwittingly dating a relative. Most people can just move out of town to escape this problem. Things aren't so simple when you live in Iceland, where family names don't exist and nearly everyone knows someone who accidentally fell for a not-so-distant cousin.

The country's 300,000 residents can lay their fears to rest now, thanks to Íslendingabók (the Book of Icelanders), a genealogy search tool that helps clear up any confusion about family ties.

Virtually every Icelander since the 18th century is in the database [...] Any Icelander living now can sign up for a username and password and gain free access to some of the data, such as names and birth dates, and view full information on everyone who shares a great-grandparent with them. One can also find out if they have common ancestry with any given Icelander and uncover their exact lines of descent.

Some have also used it to see how closely related they are to celebrities, most notably, Björk:

Alli Thorgrimsson, for example, learned that he and Björk are related seven generations back, on both sides. He shares a closer ancestral tie with the current prime minister, Jóhanna Sigurðardóttir. Thanks to Íslendingabók, he also knows that his ex-wife was his seventh cousin, or in other words, not close enough to trigger an incest alarm.

Íslendingabók seems a little weird initially, but for Icelanders, it's a valuable tool. At any rate, it's a lot more effective than the tradition of asking, “Hverra manna ert þú?” (Who are your people?), which leaves a little too much room for error.