I once read the dating life in Iceland can be kind of difficult. The total population is around 400k after being settled for almost 1150 years. Thus, it's quite common on first dates for both individuals to go through their family trees. Not to see if they are related, but to make sure they aren't too related.

It turns out that Icelandic people even have an app for it now.

https://www.cbc.ca/news/business/kissing-cousins-icelandic-a...