Determining relative relationship includes receiving recombinable deoxyribonucleic acid (DNA) information of a first user and recombinable DNA information of a second user, determining, based at least in part on the recombinable DNA information of the first user and recombinable DNA information of the second user, a predicted degree of relationship between the first user and the second user, and in the event that the expected degree of relationship between the first user and the second user at least meets the threshold, notifying at least the first user about a relative relationship with the second user.