Board Thread:Wiki Discussions/@comment-25134516-20140703093231/@comment-25134934-20140703141826

True, they acquire the same chakra frequency that's why the Sage of 6P was able to recognize him...but still think about it. Rinnegan (Samsara's cycle), transmigration, the whole show is based upon buddhist and hinduist beliefs, so in a reincarnation you have the very same spirit or will of your predecessor, don't believe me? Just look at hashirama's and naruto's actions and madara's with Sasuke's (until he turn out to be good...or at least that's what it looks like)...it fits.