Much research has been written on how birth order affects family relationships. In terms of esteem, view of the family dynamic, and one’s ability to enter successfully into romantic relationships, birth order has been found to play a significant role (Kidwell, 1981; Kidwell, 1982; Schilling, 2001). The purpose of this paper is to examine social, mental and biological factors of birth order while also examining an individual’s position in the family and how it may have an impact on behavior and personality.
Birth order refers to the numerical position of a person who is born in a family (Schilling, 2001). For the purposes of this paper, the discussion will focus primarily on three groups—first born, middle born, and last born. These three groups comprise three distinct experiences of place within the family context. The eldest born is the first child: he has no older siblings from whom to get an example. He sets the example for his younger siblings. His attitudes and experience are different from the middle born, who sees in the eldest an example and can play off that example, respond to it, and think on it. The last born is in a different position altogether. He is viewed differently and perhaps more sentimentally by parents than the other two—for one reason being that he is the last born and no more children follow. It is why the last born is often referred to as the baby of the family. He typically receives more doting affection than the other two, while the oldest is typically given a greater degree of responsibility by virtue of his being oldest and first into the world. The middle born tends to be the forgotten child, feeling not quite so confident as the oldest nor quite so loved as the youngest (Kidwell, 1982). Gender, too, plays a factor in the development of these children’s perspectives (Kidwell, 1981). Thus, birth order is not alone in serving as a factor in the social, mental and biological development of a child; but it is an important factor.

Schilling (2001) looks specifically at how birth order affects the development of three types of relationships: same-sex friendships, opposite-sex friendships and opposite-sex romantic relationships. 91 people were surveyed for the study, which means it was not a large sample that would ensure validity or generalizeability; however, it does serve as a starting point for analyzing whether birth order is a factor in the success of establishing relationships. What Schilling (2001) found was that there appeared to be no correlation between birth order and any of the three types of successful relationships, meaning that anyone born at any place in the order of children in a family could have any type of successful relationship, platonic or romantic. What the study did find that was compelling, however, was that birth did appear to be a factor in unsuccessful romantic relationships. Those romantic relationships that tended to fail most of all were when the two people in the relationship were of the same birth order. For example, they might both be first born children or middle born children or last born children. This was an interesting finding because it suggested that in...…studies reviewed in this paper.

Still, the other studies are also compelling in their own ways, primarily because each is looking at birth order from a different perspective and adding something to the body of knowledge. The study by Schilling (2001) was helpful in pointing out that birth order does affect one’s ability to have successful romantic relationships with others, because each child has specific needs and personality type and this can produce a clash of personalities if they are too much alike, evident from their having the same birth order in the birth timeline. If they are from different parts of the birth timeline they are more likely to have a successful romantic relationship.

The two studies by Kidwell (1981, 1982) focused on birth order to see how it impacted the mental development of children as well as the development of self-esteem. These were interesting studies even if the samples were much smaller than those of the study by Rohrer et al. (2015). Sulloway (2001) looked at the biology of birth order and how it leads to the advent of sibling competition. Rohrer et al. (2015) sought to confirm or deny earlier findings suggesting that birth order is a factor in development. Their study did show that birth order impacts intelligence levels but they found no signs of an impact on personality, seemingly contradicting the study by Schilling (2001). What makes studies helpful, however, is not always what they show but they arrive at their conclusions. Thus, methodology is important to consider anytime one is giving weight to a single conclusion.