Alfred Adler’s birth order theory suggests that your personality is affected by the order in which you were born in your family.
We’ve all heard the clichés. You might tell someone who’s attention-seeking that they have “middle child syndrome.” You might guess that someone is the oldest child because they boss everyone around.
These ideas were first brought forth by 20th-century Austrian psychotherapist Alfred Adler, who had a theory that our personalities develop based on our birth order within our families.
Many psychotherapists use this theory today, but is it based on science?
While some aspects of Adler’s theory may hold some truth, it’s not the case for everyone. A person’s personality is defined by more than birth order and family dynamics.
Alfred Adler, an Austrian psychotherapist, developed the birth order theory in the early 1900s.
He proposed that the birth order position in which a child is born significantly affects their personality and life outcomes, including their career and educational success.
For example, firstborn children have a certain set of personality traits, while only children have others, and so on.
According to Adlerian theory, kids who grow up within the same family can have different experiences. Adler said that your birth order and the number of siblings you have significantly affect your potential and personality.
He also claimed that “psychological birth order” — or your perceived position within your family — is more crucial than numerical birth order, which can sometimes be different. For example, someone may be a middle child but take on oldest-child responsibilities if the chronologically eldest sibling is disabled.
The birth order theory wasn’t Adler’s only theory of personality development, but today it remains his most well-known one.
Many research studies have been conducted to determine whether Adler’s birth order theory has any scientific merit.
A 2010 review of 200 studies on birth order found that many personality traits were associated with birth order to a statistically significant level. But the authors admit that they didn’t include any studies with nonsignificant results in their review.
But other recent analyses of these studies have found that birth order may have some effect on a child’s development — but not as profound of an effect as Adlerian theory claims.
For example, a 2015 review found that firstborn children had higher levels of intellect than children in other birth order positions. But the researchers found no differences between firstborn children and others in terms of broader personality traits such as extraversion, emotional stability, or imagination.
A 2015 study of U.S. high school students found no statistically significant association between birth order and intelligence or personality traits.
A 1992 review determined that Adlerian theory may have gotten it right when it comes to the personality traits of firstborn children. But they also mentioned that the research that’s been done on birth order theory has many flaws and limitations.
Other studies support this finding on firstborns. For example, a 2018 article found that firstborns were more likely to be leaders and have personality traits such as persistence and emotional stability.
So does birth order affect personality? More research is needed to be able to say for sure, but many still believe in Adlerian’s birth order theory and use it to explain personality differences.
According to the Adlerian birth order theory, firstborn children benefit from the extra attention given to them before their younger siblings are born. But your position of power is taken away when the next child is born.
The eldest sibling has high expectations placed upon them as they’re expected to set a good example for their siblings.
Adlerian theory states that firstborn children tend to be authoritarian and feel entitled to power. They find themselves in leadership positions as adults. Research also shows that firstborns may have slightly higher intelligence than their younger siblings.
According to this theory, traits of the firstborn or oldest child include:
The “middle child syndrome” cliché comes from Adlerian birth order theory.
According to Adler, middle children often feel squeezed between their older and younger siblings. They feel like they’ve been robbed of any position of significance within the family.
Middle children can become competitive or rebellious. But they can also be even-tempered, being able to compromise between family members.
Other personality traits may include:
- people pleaser
- social butterfly
The youngest child is the “baby” of the family, and this position is never taken away from them. As a result, the youngest child can become spoiled by the parents and older siblings in the family.
This can lead to the youngest children wanting to become “bigger” instead of being the perpetual baby. They may make big plans for their lives that don’t pan out.
The youngest child may also have the following personality traits:
Adlerian theory suggests that only children are often “miracle babies.” They enjoy complete attention from both parents, which can lead to them being spoiled like the youngest children.
They often don’t have to share their parents with siblings, so they may have difficulty sharing attention and belongings as they age. Since they grow up with adults and no peer siblings, they may seem mature for their age and talk and act like “little adults.”
Other personality traits of only children may be:
Adler created the birth order theory to explain personality development and differences, not necessarily to explain mental health issues.
Our understanding of mental health was still very limited during Adler’s life. He considered firstborns to be more “neurotic,” a term used to describe anxious but not psychotic symptoms.
More recently, researchers have examined the relationship between birth order and mental health conditions.
A 2021 study found that the youngest children had the lowest rate of mental health challenges, including emotional, conduct, and attention problems. Youngest children also scored higher on prosocial behavior and resilience. Middle children had the lowest happiness scores across all groups.
A 2019 study seemed to contradict Adler’s theory that firstborns are more neurotic. Higher birth orders were associated with both increased rates of suicide attempts as well as psychiatric diagnoses. In other words, the youngest children had the highest rates of mental health problems.
But firstborn children were more likely than later-born children to be emotionally unstable, according to a 2015 study.
So, is birth order associated with mental health issues? According to the research, probably not.
Mental health conditions are caused by a combination of environmental, biological, and genetic factors. If your birth order caused some sort of childhood trauma for you, then the trauma itself could potentially contribute to a higher chance of mental health conditions.
Birth order theory, originally created by Alfred Adler over a hundred years ago, is an interesting theory that suggests your birth order plays a large role in your personality development.
Many people continue to study and use the birth order theory for psychotherapeutic purposes. But the research about this theory’s validity is limited and conflictual.
If you’re experiencing challenges or concerns with your personality, consider reaching out to a mental health professional. They can help you address these concerns and determine whether any underlying issues may be the cause.
If you’re unsure where to start, you can check out Psych Central’s hub for finding mental health support.