I don't know too much about overall percentages -- at least not with the algorithm 23andme uses. For example, I have a proven 2nd cousin once removed and our overall match is 1.76% and her son (my 3rd cousin) matches 1.02% total DNA according to 23andme. However, our match is through The cousins' paternal side and my maternal side. Where we match most closely is our X chromosomes and this stands to reason -- since the son only inherited a single X (and it came from his mother which is our matching side--through the mother's father on back), the match is with the X I inherited from my father--the line we share. We have half identical matches for more than 90% of the X chromosome and only one other fairly large matching segment on chromosome 2. Joan In a message dated 6/1/2010 10:16:32 A.M. Eastern Daylight Time, [email protected] writes: Now, the "theoretical" amount of DNA one shares with a 1/2 first cousin is 6.25%. But in the "real world" the actual percentage could be as much as a point or two higher or lower.