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Birth Order Shapes Personality: True or False?

West, O. (2023, January 16). Birth Order Personality Traits: 4 Types Of Children In A Family. Retrieved from

Labels are often assigned to children based on the order in which they were born. If you’re the oldest, be responsible. If you’re the middle child, learn to compromise. If you’re the youngest, you are spoiled. If you’re an only child, good luck on your own. These are merely the first impressions of a person when we discover their order of position in the family. However, what does psychology have to say about how birth order shapes our personalities? Is it a fact or a myth?

Birth order theory is the idea that the order in which a person is born in their family influences their personality, behaviour, and intelligence. This theory was first developed by Alfred Adler in the early 1900s; he claimed that birth order significantly affects a child’s personality and life outcomes. Adler suggested that the number of siblings that you have as well as the role you play in your family shape your potential and personality. His theory has led to many debates among psychologists today on whether our birth order has a major impact on our personality development or not.

The Roles:

First-born children are the most unique of all because their parents are new to parenting, so they tend to be more cautious and strict with their first child. Parents hold higher expectations for them than they would for their other children. According to Dr. Catherine Salmon, professor of psychology at the University of Redlands, firstborns tend to “score high on conscientiousness,” she explains, “due to their surrogate parent role in the family and the responsibilities that go with that” (MedPsych, 2019). Personality traits that are often associated with firstborns are being responsible, determined, hard-working, cautious, bossy, and being a role model to their youngest siblings.

The middle child is often portrayed as “the lost child” in some aspects of the media because of the lack of parental attention they receive. They are squeezed between the oldest and the youngest; hence, they tend to share everything with their other siblings. Their familial experience prepares them to be “diplomatic, nurturing, introspective, tentative, and have a tendency towards keeping the peace” (MedPsych, 2019). Middle children are considered to be adaptable, humorous, competitive, rebellious, and great negotiators.

Youngest children are usually stereotyped as spoiled because of their position as the “baby” of the family. Their parents tend to be lenient with them because they have spent more energy on their older children, so they may decide to be laid-back with their younger kids. Dr. Salmon states that in general, “high agreeableness, extraversion (the social dimension), and openness are associated with the youngest children, and sometimes low conscientiousness due to a lack of responsibilities and parental indulgence over expectations” (MedPsych, 2019). Some traits that are typically labelled for the youngest children are risk-taking, outgoing, dependent, persistent, fun-loving, charming, easy-going, and free-spirited.

An only child is, in some ways, similar to the youngest child because of the great amount of attention that their parents provide them with. However, the only child may also possess a few similar traits as the firstborn child because they are the first child of their parents, so they may have high expectations and pressure placed on them. Without any siblings, only children have “different influences, no sibling competition, and are the sole focus of parental investment” (MedPsych, 2019). An only child could harbour traits of maturity, loyalty, independence, confidence, leadership, caution, curiosity, and sensitivity.

Does birth order affect personality?

Although it is possible that the order in which a child is born shapes their personality, not every family is systematised the same way. In one study, Julia Rohrer of the University of Leipzig and her colleagues Boris Egloff and Stefan Schmukle examined data from 20,000 adults in the United States, Germany, and England. In addition to comparing siblings in the same family, they also looked at differences between families. Rohrer determined that over a life’s course, “birth order does not have a lasting effect on broad personality traits outside of the intellectual domain.” She found "no birth-order effects on extraversion, emotional stability, agreeableness, conscientiousness, or imagination. This finding contradicts lay beliefs” (Psychology Today, 2015). According to this research, the differences between children may not be related to their position in the family; rather, they could be an effect of age. For instance, a younger sibling may become more conscientious with time or as conscientious and reliable as their older sibling. This phenomenon is considered an age effect. If it is taken into account that children change as they grow older, the usual traits that are often associated with birth order could sometimes apply during their younger years because other factors contribute to shaping their personality.

Different elements affect social family dynamics and can result in shaping children differently than what the birth theory has proposed. Parental attitudes and culture are huge factors, especially when it comes to the gender of the child. In some cultures, the female child is expected to contribute more to household activities than the male child, regardless of which order they were born in. While in other cultures, the male child can be treated as the oldest even if he was born as the youngest after his female siblings (WebMD, 2023). There are diverse cultures with different traditions, so birth order theory would not entirely apply in some circumstances. Another factor is the age difference between the children, because depending on the age gap, there will be differences in how the parents treat each child and how the children interact with each other.


There are various components that comprise every family, which is why we are all so diverse. Birth order is affected by more than one element, so before relying on the stereotypical labels of someone based on their position in the family, it is important that we first understand the other factors in their life before formulating assumptions. Although birth order theory does shape our personalities in some ways, there are other factors to consider as well.


Brennan, D. (2023, July 12). Birth Order: What You Should Know. WebMD. Retrieved October 25, 2023, from

Juby, B. (2022, October 11). Does Birth Order Impact Personality? I Psych Central. Psych Central. Retrieved October 25, 2023, from

Newman, S. (2015, November 17). Does Your Birth Order Actually Matter? Psychology Today. Retrieved October 25, 2023, from

What Your Sibling Birth Order Reveals About Your Personality Traits (Even If You're an Only Child). (2021, August 19). Comprehensive MedPsych Systems. Retrieved October 25, 2023, from


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