I’m a man who recently took a 23andMe test, and I have a question about Relative Finder. Another man who I match on 36 of 37 Y-DNA markers via Family Tree DNA also took a 23andMe test. We believe that we are third cousins, but this individual does not show up as related in Relative Finder, nor does he show any similarities in the Family Inheritance section. Does this mean that we are not related at all?
If two individuals do not share any DNA in the Family Inheritance section of 23andMe or do not appear as relatives in Relative Finder, this absolutely does not mean that they are not or cannot be relatives. It does suggest, however, that the two individuals might not share any DNA. Although your Y-DNA test suggests that you share a recent common male ancestor, it appears that apart from your Y chromosomes you do not share any other DNA.