Birth order refers to the order a child is born in relation to their siblings, such as whether they are first-born, middle-born, or last-born. You’ve probably heard people joke about how the eldest child is the bossy one, the middle child is the peace-maker, and the youngest child is the irresponsible rebel—but is there any truth to these stereotypes?
Psychologists often look at how birth order can affect development, behavior patterns, and personality characteristics, and there is some evidence that birth order might play a role in certain aspects of personality.
What Is Adler’s Birth Order Theory?
Early in the 20th century, the Austrian psychiatrist Alfred Adler introduced the idea that birth order could impact development and personality. Adler, the founder of individual psychology, was heavily influenced by psychoanalyst Sigmund Freud.
Key points of Adler’s birth order theory were that firstborns were more likely to develop a strong sense of responsibility, middleborns a desire for attention, and lastborns a sense of adventure and rebellion.
Adler also notably introduced the concept of the “family constellation.” This idea emphasizes the dynamics that form between family members and how these interactions play a part in shaping individual development.
First-Born Child
Adler’s birth order theory suggests that firstborns get more attention and time from their parents. New parents are still learning about child-rearing, which means that they may be more rule-oriented, strict, cautious, and sometimes even neurotic.
They are often described as responsible leaders with Type A personalities, a phenomenon sometimes referred to as “oldest-child syndrome.”
“Older siblings, regardless of gender, often feel more deprived or envious since they have experienced having another child divert attention away from them at some point in their lives. They tend to be more success-oriented,” explains San Francisco therapist Dr. Avigail Lev.
Firstborn children are often described as:
- Leaders
- High-achieving (or sometimes even over-achieving)
- Structured and organized
- Responsible
- Mature
All this extra attention firstborns enjoy changes abruptly when younger siblings come along. When you become an older sibling, you suddenly have to share your parent’s attention. You may feel that your parents have higher expectations for you and look to you to set an example for your younger siblings.
Consider the experiences of the oldest siblings, who are frequently tasked with caring for younger siblings. Because they are often expected to help fill the role of caregivers, they may be more nurturing, responsible, and motivated to excel.
Such traits are affected not only by birth order but also by how your position in the family affects your parent’s expectations and your relationship with your younger siblings.
Research has found that firstborn kids tend to have more advanced cognitive development, which may also confer advantages when it comes to school readiness skills.2 However, it’s important to remember that being the oldest child can also come with challenges, including carrying the weight of expectations and the burden of taking a caregiver role within the family.
Middle Child
Adler suggested that middle children tend to become the family’s peacemaker since they often have to mediate conflicts between older and younger siblings. Because they tend to be overshadowed by their eldest siblings, middle children may seek social attention outside of the family.
In families with three children, the youngest male sibling is likely to be more passive or easy-going.
Middleborns are often described as:
- Independent
- Peacemakers
- People pleasers
- Outgoing
- Adaptable
- Attention-seeking
- Jealous
- Competitive
- Insecure
While they tend to be adaptable and independent, they can also have a rebellious streak that tends to emerge when they want to stand apart from their siblings.
“Middle child syndrome” is a term often used to describe the negative effects of being a middle child. Because middle kids are sometimes overlooked, they may engage in people-pleasing behaviors as adults as a way to garner attention and favor in their lives.
While research is limited, some studies have shown that middle kids are less likely to feel close to their mothers3 and are more likely to have problems with delinquency.
Some research suggests that middle children may be more sensitive to rejection. As a middle child, you may feel like you didn’t get as much attention and were constantly in competition with your siblings. You may struggle with feelings of insecurity, fear of rejection, and poor self-confidence.
Last Child
Lastborns, often referred to as the “babies” of the family, are often seen as spoiled and pampered compared to their older siblings. Because parents are more experienced at this point (and much busier), they often take a more laissez-faire approach to parenting.
Last-born children are sometimes described as:
- Outgoing
- Fun-loving
- Charming
- Free-spirited
- Immature
- Manipulative
- Self-centered
- Dependent
- Risk-taking
Adler’s theory suggests that the youngest children tend to be outgoing, sociable, and charming. While they often have more freedom to explore, they also often feel overshadowed by their elder siblings, referred to as “youngest child syndrome.”
Because parents are sometimes less strict and disciplined with last-borns, these kids may have fewer self-regulation skills.
“If the youngest of many children is female, she tends to be more coddled or cared for, leading to a greater reliance on others compared to her older siblings, especially in larger families,” Lev suggests.
Only Child
Only children are unique in that they never have to share their parents’ attention and resources with a sibling. It can be very much like being a firstborn in many ways. These kids may be doted on by their caregivers, but never have younger siblings to interact with, which may have an impact on development.
Only children are often described as:
- Mature
- Diligent
- Thoughtful
- Perfectionistic
- High-achieving
- Imaginative
- Self-reliant
- Sensitive
Because they interact with adults so much, only children often seem very mature for their age. If you’re an only child, you may feel more comfortable being alone and enjoy spending time in solitude pursuing you own creative ideas. You may like having control and, because of your parents’ high expectations, have strong perfectionist tendencies.
How Birth Order Influences Relationships
Birth order may affect relationships in a wide variety of ways. For example, it may impact how you form connections with other people. It can also affect how you behave within these relationships.
Dr. Lev suggests that the effects of birth order can differ depending on gender.
“For instance, in a family with two female siblings, the younger one often appears more confident and empowered, while the older one is more achievement-focused and insecure,” she explains.
She also suggests that there is often a notable rivalry between same-sex siblings versus that of mixed-gender siblings. Again, this effect can vary depending on gender. Where an older sister might be less secure and the younger sister more secure, the opposite is often true when it comes to older and younger brothers.
“This could be because older sisters often assume a motherly role, while older brothers might take on more of a bully role. As a result, younger brothers are generally more insecure, whereas younger sisters tend to be more confident than their older siblings,” she explains.
Some other potential effects include:
Communication
Birth order can affect how you communicate with others, which can have a powerful impact on relationship dynamics.
- Firstborns and only children are often seen as more direct, which others can sometimes interpret as bossy or controlling.
- Middle children may be less confrontational and more likely to look for solutions that will accommodate everyone.
- Lastborns, on the other hand, may rely more on their sense of humor and charm to guide their social interactions.
Relationship Roles
Birth order may also influence the roles that you take on in a relationship.
- Firstborns, for example, may be more likely to take on a caregiver role. This can be nurturing and supportive, but it can sometimes make partners feel like they are being “parented.”
- Middle children are more likely to be flexible and take a more easygoing approach.
- Lastborns may be more carefree and less rigid.
Expectations
What we expect from relationships can sometimes also be influenced by birth order.
- Firstborns often have high expectations of themselves and others, sometimes leading to criticism when people fall short.
- Middle children are more prone to seek balance in relationships and want to make sure that everyone is treated fairly and contributing equally.
- Lastborns may place the burden of responsibility on their partner’s shoulders while they take a more laissez-faire approach.
“Generally, older siblings are more likely to be in the scapegoat role, while the youngest siblings often have a more idealized view of the family,” Lev explains.
Other Factors Play a Role
How birth order influences interpersonal relationships can also be influenced by other factors. Some of these include personality differences, parenting styles, the parents’ relationship with one another, and even the birth order of the parents themselves.
Debunking Myths and Limitations
While birth order theory holds a popular position in culture, much of the available evidence suggests that it likely only has a minimal impact on developmental outcomes. In other words, birth order is only one of many factors that affect how we grow and learn.
While some research suggests that there are some small personality differences between the oldest and youngest siblings, researchers have concluded that there are no significant differences in personality or cognitive abilities based on birth order.6
Birth order doesn’t exist in a vacuum. Genetics, socioeconomic status, family resources, health factors, parenting styles, and other environmental variables influence child development. Other family factors, such as age spacing between siblings, sibling gender, and the number of kids in a family, can also moderate the effects of birth order.