Methods for identifying biological relationships With the continuous development of society, more and more people have doubts about their biological relationships. If you have such concerns, you may want to get a paternity test. The traditional paternity test method is to determine kinship through DNA testing, but this method is expensive and requires the assistance of a doctor. So are there other ways to determine biological relationship? Below we will introduce several methods of identifying biological relationships. 1. Physiognomy The inheritance of appearance is a very common inheritance method. Therefore, it is a very important method to judge kinship through facial appearance.