Social psychologist roy baumeister makes the case that, on average, most people want close, important relationships in their lives at any given time.

The answer in the space provided is four to six as it is handful and enough for a person in terms of having a relationship towards other people over time as it is enough for a person to be supplied with his or her needs in a relationship with other people that he or she could be close to and could be considered to be as one of the important people in his or her life.