Biologists ... wrote:
Biologist would not recommend procreation by second or third cousins. The risk for birth defects are greater than two non-relatives mating. Would not dating a second or third cousin be awkward at family/social gatherings?
Who has family gatherings with their 3rd cousins? I have 2nd cousins that I was friends with for years before I found out we were 2nd cousins. All of my holiday family gatherings were with my grandparents and their descendants.
The actual scientific statistics-based arguments I've seen in the past on this topic say that while marrying 1st cousins might be legal it's somewhat risky and not advisable. But I've never seen anyone argue from data or statistics that there's any issue at the 2nd cousin level or beyond.
Personally I wouldn't ever date anyone that I knew was a cousin of any kind because there's such a big social stigma about it--whether that stigma is justified or not. But I personally wouldn't stigmatize someone else or think they're disgusting if they were with a 2nd or 3rd cousin. I personally don't buy any arguments about there being some reason why it's gross to marry someone you grew up with, because that same rationalization should mean people can't marry unrelated friends that they knew in childhood. For me it's just a question of science and statistics and probabilities. Based on the data I've seen, there shouldn't be issues with 2nd cousins or beyond, but I'd be happy to change my mind if it turns out that data isn't correct. I don't see any reason to be grossed out or to be stigmatizing anyone based on this stuff. Just make rational decisions based on the data.