Birth Order Theory: Insights Into Your Personality

By Mary Elizabeth Dean|Updated September 1, 2022

Developing one's personality can come from a variety of sources and influences in a child's life, it can be fascinating, and important to understand those influences. One great way to understand the influence of birth order on one's personality is to discuss it with a therapist as they may be able to help you identify parts of your identity and how they developed. Understanding this and other aspects of one's identity is only one reason therapy can be beneficial. Having an online therapist can also help.

Learn More About How Birth Order Has Influenced Your Life

The study of personality and its formation has interested researchers, psychologists, and scientists for centuries. Personality refers to an individual's different patterns of thinking, behaving, and feeling. People's personalities encompass nearly every aspect of their human experience. Studying variables like personalities usually falls into two categories:

  • Understanding differences in people's personality characteristics- like temperament, sociability, and motivation
  • Discovering how various parts of a person come together as a whole

There are many theories of how personality forms, adapts, and is affected by one's external environment that vary across cultures and associations. One personality study focuses on a person's birth order, and their subsequent relationships with their siblings. Birth order theory was developed by Alfred Adler in the twentieth century; it stated: the order in which a child was born impacted his or her personality. We will go over this idea further in this article.

Birth Order Theory: Adler's Research

Alfred Adler was born just outside Vienna in 1870. He started his medical career as an ophthalmologist; then, switched to general practice in a less affluent part of Vienna. In 1907, he met Sigmund Freud and developed a working relationship with him and other prominent psychoanalysts of the time. As Adler progressed in his career, he sought to create a psychological movement based on a holistic view of an individual. Unlike Freud, Adler believed the social and community aspects of a person's life were just as important as internal thoughts and emotions. Adler's desire to understand how social factors influence personality extended to child development. His birth order theory described how the effect of birth order shaped a child's thoughts and behaviors from first born children to the youngest children, as well as all in between.

What Birth Order Theory Is Not

Birth order personality traits are not necessarily present when a child is born into a family. For example, firstborn children are not born with niche or particular personality traits ingrained in their psyche. Instead, in birth order theory, Adler illustrates how family environments and dynamics play a role in shaping individual psychology during a child's formative years. Though every family is different, there are many similarities between the interactions of parents and children, as well as siblings, as kids grow and develop in the same family.

The Family's Role in Birth Order Personality Traits

Birth order research and studies show that there are several influences shaping personality in addition to birth order personalities. Common factors include:

  • Biological: Children inherit many traits and features from their parents. These include intelligence, courage, and physical features.
  • Social: By interacting with others in an individual's social circle, children learn behaviors and thought patterns from their experiences, like those in the education system and beyond.
  • Cultural: A child growing up within a culture consciously or unconsciously adopts traits consistent with the culture's beliefs, ideas, and norms.
  • Physical Environment: An individual's surroundings often impact the development of personality. For example, the personalities of those growing up in a rural area are often very different from those living in an urban environment.
  • Situational: As a child grows, they face different situations, which help them adapt and change aspects of their personality. This could be meeting new friends, experiencing a trauma, or, of course, welcoming a new sibling.

When looking at these factors, we see family life can incorporate all of these. Since most children's lives are, at first, shaped by everything going on in the family, it is no wonder birth order theory has remained relevant throughout the decades.

The following traits are general examples of how birth order differences and personality are related. Of course, many other factors could impact the average development of a child's personality; some of these reasons will be discussed later.

Only Children

These children tend to get much more attention from adults than a child with siblings. This means many of their early interactions involve individuals significantly older than them. These interactions can make them feel like "tiny adults," and they can seem more mature than peers with siblings. Traits include:

  • Confidence
  • Mature for their age
  • Sensitive
  • Uses adult language
  • Self-centered
  • Pampered and often spoiled
  • Enjoys being the center of attention
  • Feels unfairly treated when not getting their own way
  • May refuse to cooperate with others
  • Desire to be more like adults, so may not relate well with peers
  • Can be manipulative to get their way

First Child

Since the firstborn child is used to being an only child until the later-borns come along, he or she may exhibit some of the characteristics of an only child. Also, the firstborn may have these birth order personality traits:

  • Achiever and leader
  • Feels must have superiority over other children
  • May have difficulty when the second child is born, such as feeling unloved or neglected
  • Can be controlling and focused on being correct about results
  • Uses good (or bad) behavior to regain parents' attention
  • Bossy or authoritarian about rules
  • Strives to please others
  • Reliable
  • Can be protective or helpful towards others

Learn More About How Birth Order Has Influenced Your Life

Second Child

The second born children and middle children began their lives, sharing the attention of their parents with the firstborn. By having an older sibling as a role model, the second born often tries to catch up with the older children. Adler believes the second child is most likely to be better adjusted in life. A second child could be:

  • More competitive
  • Lacking the undivided attention of parents
  • A people pleaser
  • A peacemaker
  • Developing abilities the first child doesn't exhibit to gain attention
  • Rebellious
  • Independent and does not need the support of others

Middle Child

Many have heard of the "middle child syndrome" and the difficulties these children can present. Considering the significant changes they deal with early in life, it's no wonder they could become frustrated or resentful. Not only do they lose their "youngest child" status, but they also have to share their attention with older and later born children. Middle born of bigger families often aren't as competitive as single middle children, since their parents' attention is spread thinner for bigger family dynamics. Middle children in bigger families are more prone to using cooperation to get what they want. Middle child traits include:

  • Can feel life is unfair
  • Can be even-tempered
  • May feel unloved or left out a lot
  • Doesn't have the rights and responsibilities of the oldest sibling or the privileges of the youngest
  • Adaptable
  • Impatient
  • Outgoing and rambunctious
  • Learns to deal with both older and younger siblings
  • Treating younger siblings rougher
  • Feel "squeezed" in the family environment

Youngest Child

The last born child cannot be dethroned by a younger sibling. The "baby" of the family tends to get more attention from parents, since the older siblings are developing and becoming more independent. Traits of the youngest child:

  • Charming and outgoing
  • Attention seeker
  • Can behave like the only child
  • Feels inferior- like everyone is bigger or more capable
  • Expects others to make decisions and take responsibility
  • May not be taken seriously
  • Can become "speedier" in development to catch up to other siblings

Other Factors Influencing Birth Order Personality

As we all know, each family is different and has unique dynamics. The subject of birth order positions alone will not determine the complexities of one's personality. As child and family develop and evolve, certain circumstances or measures may impact the personality of a child. Across different families, children of the same birth order will show diverse personality differences, especially across a large representative sample.

Blended or Step-Families

When two parents remarry, especially when children are in their formative years, the family unit goes through a period of disorientation and competition. For example, two firstborns in the new family will search for their "place" and may compete to keep their "first born status" with the new family size and information.

Differences in Ages

When there is an age gap of three or more years between siblings, it is common for the birth orders to restart. In a family with many children, this could create birth order subgroups with varying birth order effects.

Health and Mental Issues

A child born with significant physical or neurodevelopmental disabilities can remain in the "youngest" position regardless of the birth order. This impacts the psychological birth order position of the other children.

Gender of Siblings

The most psychological competition occurs between children of the same gender similar in ages. The competition, in part for parental attention, can start in childhood and move into young adulthood and beyond.

Death of A Sibling

The impacts of a child's death are devastating for families. This includes the personalities of the surviving siblings. Some children may adapt by developing overindulgent tendencies. Also, a glorification of the deceased child can occur- where other siblings could never live up to the pristine image of the deceased sibling. This can deeply alter the birth order effect.


An adopted child often has special circumstances in the family dynamic. For parents with difficulties conceiving, having an adopted child may be seen as a special gift. These parents have a greater tendency to spoil or overindulge the child. When an adopted child comes into an established family, he or she may find difficulties fitting into the dynamic. Emotional struggles due to not being wanted by birth parents and not fitting in with biological siblings are common. Sometimes these feelings of inadequacy warrant therapy.

Does the Correlation of Birth Order and Personality Exist?

Previous research and science has linked higher intelligence to family's eldest children. This could be due to the fact that parents have more emotional and intellectual resources to give when fewer children are present in the body of the family.

In a study of more than 20,000 participants, however, data revealed no significant effects of birth order of the Big Five personality traits. These include extraversion, emotional stability, agreeableness, conscientiousness, and openness to experience.

Does this mean birth order theory should be discarded? Probably not. This only proves the formation of personality is not simply explained by a child's birth position in the family. Multiple factors, including socioeconomic status, parental attitudes, gender roles, and social influences, also contribute to shaping an individual's personality. Birth order may explain some everything from people's tendencies to career and relationship outcomes, but everything going on in a person's life must be considered. All factors must be considered in the development of personality, including psychology, sociology, and economic research.

If you are struggling with emotional issues, a psychotherapist may be able to illuminate how your personality plays a part. Psychotherapy can help find the root cause of some issues while allowing you to discover the necessary changes needed to live a happy, fulfilling life. If a traditional therapy setting is too cost-preventative or not a feasible option, consider using affordable online counseling through BetterHelp. The licensed and accredited therapists of BetterHelp can give you a new option for regaining emotional control of your life. Read below for some reviews of BetterHelp counselors, from people experiencing issues related to family and birth order.


Your personality may or may not have anything to do with your birth order. There are many things you can do to become attuned to yourself and your personality. If you find your personality is causing you stress, a therapist can help. The only thing standing between you and your peace is a few clicks. Take the first step today.

Here are some popular questions about the topic:

Which birth order is most successful?
What did Adler say about first borns?
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Is birth order theory nature or nurture?
Which sibling is usually the smartest?
Are middle children smartest?
Why is the first born son so important?
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