How Does Birth Order Affect Family Relationships?

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 order for a romantic relationship to work, the two partners should be of different birth orders. It suggests that the different birth order is what plays a part in the development of different personalities, which might complement one another.
If different personalities develop as a result of birth order, why is this? Kidwell (1981) looks at the way sibling structures and birth order as well as gender all play a part in determining the mental development of adolescents. In particularly, Kidwell (1981) looks at how adolescents perceive the power and supportiveness of their parents. Sibling structure is defined as a hypothetical timeline on which siblings are born and what the space between births is. Kidwell (1981) looked at 1700 adolescent males and found that when the closest sibling of a male is a female the perception that males tends to have of parents is that parents are more punitive. When a male’s closest sibling is also a male, the perception of parents is more supportive. This finding is interesting because it suggests that parents might treat children differently based on gender and that treatment is seen by siblings who are close. So for example on a timeline of five children the oldest is male, the second is male, the third is female, the fourth is male, and the fifth is female, the fourth child is going to see his parents as more punitive. This is theoretically because he sees how the parents are to the two females born on either side of him on the timeline. Ostensibly, the parents are gentler with the females than with him, so the perception he develops in his mind is that his parents are harsh with him. The oldest two boys, however, will have a different perception of their parents because they will have a male close to them on the birth time line, which will give them a sense of power.
In another study, Kidwell (1982) looks at the self-esteem levels of middle born children as compared to first born and last born. The study looked at 2200 adolescent males from a nationwide survey. Kidwell (1982) found that middle born children have significantly less self-esteem than first born or last born children. Kidwell (1982) interpreted the findings using uniqueness theory, arguing that there is something unique about the first born and the last born, but nothing special about the middle born. The parents give special attention to the children on the bookends of the birth timeline but the middle child’s role is not as clearly defined and thus he lacks a solid sense of self or of self-confidence.
Sulloway (2001) looks at how birth order impacts sibling competition and whether there is something biological about sibling rivalry. The argument of a biological basis for sibling competition is rooted in the theory of human evolution, and Sulloway (2001) posits that birth order plays a biological role in how siblings grow up because of the dictates of evolution. Siblings have to contest one another in order to demonstrate their worth and their value in the eyes of the family. Sulloway (2001) states that “a biological propensity to engage in sibling rivalry is one of the ultimate causes of personality development” (p. 40). It is a Darwinian theory of natural selection that draws the focus to the biological components of each child. The child competes for attention and favor from the parent.
The study by Rohrer, Egloff and Schmukle (2015) seems to contradict all these earlier studies, however. Rohrer et al. (2015) conducted a large scale survey in three nations—the US, the UK and Germany. 5240 participants were from the US, 4,400 from the UK, and 10,400 from Germany. The data showed that firstborn children tend to be the most intelligent of the batch, but that as far as personality is concerned there was no evidence of birth order affecting one’s personality. Birth order might affect where one lies on the intelligence spectrum with respect to the rest of one’s siblings, but that is about all it does, according to this study. What is interesting about the study by Rohrer et al. (2015) is that it uses a large sample and thus has a much wider pool of participant data to test, unlike some of the other 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.
References
Kidwell, J. S. (1981). Number of siblings, sibling spacing, sex, and birth order: Their effects on perceived parent-adolescent relationships. Journal of Marriage and the Family, 315-332.
Kidwell, J. S. (1982). The neglected birth order: Middleborns. Journal of Marriage and the Family, 225-235.
Rohrer, J. M., Egloff, B., & Schmukle, S. C. (2015). Examining the effects of birth order on personality. Proceedings of the National Academy of Sciences, 112(46), 14224-14229.
Schilling, R. M. (2001). The effects of birth order on interpersonal relationships. The McKendree College Journal of Undergraduate Research, 1, 1-12.
Sulloway, F. J. (2001). Birth order, sibling competition, and human behavior. In Conceptual challenges in evolutionary psychology (pp. 39-83). Springer, Dordrecht.