"It is useful to know that something as simple as birth order can account for major conflicts in a relationship and that neither person is to 'blame'" (Richardson 17). When one understands, for example, that an oldest brother of brothers and an oldest sister of sisters are bound to have conflicts over who is in charge, they can stop blaming each other and accept the fact that their marriage is a difficult combination. .

             Friendships are also affected by birth order. The friends a person gets along well with are likely to be in a complementary birth position. Therefore, non-complementary birth positions may partly explain any tension that exists in the relationship. "If you take note of the kind of relationship you have with various friends and then find out there birth order, you may find that your best friends all have the same birth order" (Richardson 20). While you may have much in common with people in your same birth order, over the long haul you will probably feel most comfortable with friends from a complementary birth order, especially one that matches that of a favourite sibling. (Richardson 23 - 24).

             Also, your birth order can affect the kind of parent you are and the kind of relationship you have with your children. "If you are an oldest or a middle child you probably either had some experience or witnessed caring for a younger child" (Richardson 28). Therefore for an oldest and a middle child parenthood may come easily to them and be most fulfilling. These adults may be inclined to take too much responsibility for or be too controlling with their children, however, they may simply be good and nurturing caretakers. On the other hand, if the child is an only child or a last born, the child has not had the chance to observe any parenting other than their own. Therefore these children may feel overwhelmed by the responsibility of "being a parent" and unsure about how to do it.