Which theory specifically predicts that we will be more altruistic toward our relatives than toward close friends?

The answer is evolutionary psychology as this theory is the one responsible of having to explain the evolution of an individual in terms of their mind and their behavior in which it involves their psychological traits. In the statement above, evolutionary psychology predicts that a person is more altruistic towards relatives than close friends for this theory explains the psychological behavior of an individual and how his or her mind affects his or her way of behaving towards the society or towards other people around him or her. It explains why a person is much closer to his or her friends than of his or her relatives.