Birth Order Traits: Your Guide to Sibling Personality Differences (2023)

You can bet your paycheck that your firstborn and second-born children will be different, says Kevin Leman, Ph.D., a psychologist who has studied birth order since 1967 and author of The Birth Order Book: Why You Are the Way You Are. Psychologists like Dr. Leman believe the secret to sibling personality differences lies in birth order and how parents treat their children differently based on whether they are the oldest, the middle, the youngest, or the only child.

Meri Wallace, a child and family therapist for over 20 years and author of Birth Order Blues, agrees about this birth order theory. She says that some of the birth order influence comes from how parents tend to relate differently to first, middle, and lastborns, and some of the influence is due to a child's position in relation to their siblings. "Each position has unique challenges," she explains.

Here's what parents should know about birth order personality traits for oldest, middle, youngest, and only children.

Birth Order Traits: Your Guide to Sibling Personality Differences (1)

Firstborn Personality Traits

Simply by being a first child, the oldest sibling will naturally be raised with a mixture of instinct and trial-and-error. This often causes parents to become by-the-book caregivers who are extremely attentive, stringent with rules, and overly neurotic about the little things. This parenting style, in turn, may cause the child to become a perfectionist, always striving to please their parents.

(Video) Does Birth Order Affect Your Personality?

Firstborns tend to bask in their parents' presence, which may explain why they sometimes act like mini-adults. They're also prone to being diligent and wanting to excel at everything they do. As the leader of the pack, firstborns often tend to be:

  • Reliable
  • Conscientious
  • Structured
  • Cautious
  • Controlling
  • Achievers

Firstborn strengths

Since they have their parents to themselves before siblings arrive, the firstborn is accustomed to being the center of attention. "Many parents spend more time reading and explaining things to firstborns. It's not as easy when other kids come into the picture," says Frank Farley, Ph.D., a psychologist at Temple University in Philadelphia, who has studied personality and human development for decades.

"That undivided attention may have a lot to do with why firstborns tend to be overachievers," he explains. In addition to usually scoring higher on IQ tests and getting more education than their siblings, firstborns tend to outearn them.

Firstborn challenges

Success comes with a price: Firstborns tend to be type A personalities who never cut themselves any slack. "They often have an intense fear of failure, so nothing they accomplish feels good enough," says Michelle P. Maidenberg, Ph.D., a child and family therapist in White Plains, New York. And because they dread making a misstep, oldest kids tend to stick to the straight and narrow: "They're typically inflexible—they don't like change and are hesitant to step out of their comfort zone," she explains.

In addition, because parents give firstborns a lot of responsibility at home—whether it's helping with chores or watching over younger siblings—they can be quick to take charge (and can be bossy when they do). That burden can lead to excess stress for a child who already feels pressure to be perfect.

Middle Child Personality Traits

When a second child comes along, parents might raise them with less of an iron fist due to their previous experience. They might also be less attentive since there are other children in their lives. Therefore, the middle child is often a people-pleaser due to the lack of attention they get compared to older siblings and younger siblings.

(Video) Birth Order Traits || Insights Into Siblings Personality || Life You Live In || PsychoLeaks

"The middle child often feels left out and a sense of, 'Well, I'm not the oldest. I'm not the youngest. Who am I?'" says Wallace. This sort of hierarchical floundering leads middle children to make their mark among their peers since parental attention is usually devoted to the beloved firstborn or baby of the family. What's more, "middle children are the toughest to pin down because they play off their older sibling," says Dr. Leman.

In general, middle children tend to possess the following birth order personality traits:

  • People-pleasers
  • Somewhat rebellious
  • Thrives on friendships
  • Has a large social circle
  • Peacemaker

Middle child strengths

Middleborns tend to be go-with-the-flow types. That's because once a younger sibling arrives, they must learn how to constantly negotiate and compromise to "fit in" with everyone. Not surprisingly, Frank Sulloway, Ph.D., author of Born to Rebel: Birth Order, Family Dynamics, and Creative Lives, notes that middle kids score higher in agreeableness than both their older and younger sibs.

Because they receive less attention at home, middles tend to forge stronger bonds with friends and be less tethered to their family than their siblings. "They're usually the first of their siblings to take a trip with another family or to want to sleep at a friend's house," says Linda Dunlap, Ph.D., professor of psychology at Marist College in Poughkeepsie, New York.

All About Middle Child Syndrome


Middle child challenges

Middle kids once lived as the baby of the family until a new sibling dethroned them. Unfortunately, they're often acutely aware that they don't get as much parental attention as their "trailblazing" older sibling or the beloved youngest. That realization can make them feel like their needs and wants are ignored.

"Middle kids are in a difficult position in a family because they think they're not valued," says Dr. Maidenberg, "It's easy for them to be left out and get lost in the shuffle." And there is some validity to their complaint.

For example, research in the Journal of Human Resources in 2016 found that parents do not provide later-born children with the same cognitive support as they offered firstborn children, relaxing what they deem non-essential parenting support.

Does Birth Order Affect Personality?

Youngest Child Personality Traits

Youngest children tend to be the most free-spirited due to their parents' increasingly laissez-faire attitude toward parenting the second (or third, or fourth, or fifth) time around. As a result, the baby of the family tends to have the following birth order traits:

(Video) Birth Order & Personality

  • Fun-loving
  • Uncomplicated
  • Manipulative
  • Outgoing
  • Attention-seeking
  • Self-centered

Youngest child strengths

Since parents generally don't have their eyes as glued to lastborns as their firstborns, the youngest sibling might develop their own ways of winning attention. They tend to be natural charmers with an outgoing, social personality; no surprise then that many famous actors and comedians are the babies of their families. In addition, youngest children tend to score higher in "agreeableness" on personality tests than firstborns, according to Dr. Sulloway's research.

The youngest also make a play for the spotlight with their adventurousness. Therefore, free-spirited lastborns may be more open to unconventional experiences and physical risks than their siblings.

Youngest child challenges

Lastborns are known for feeling that "nothing I do is important," Dr. Leman notes. "None of their accomplishments seem original. Their siblings have already learned to talk, read, and ride a bike. So parents react with less spontaneous joy at their accomplishments and may even wonder, 'Why can't he catch on faster?'"

Lastborns may also learn to use their role as the baby to manipulate others to get their way. "They're the least likely to be disciplined," Dr. Leman notes. Parents often coddle the littlest when it comes to chores and rules, failing to hold them to the same standards as their siblings.

Is Only Child Syndrome Real?

(Video) Narcissism in a Sibling [How to Spot the Signs]

Only Child Personality Traits

Being an only child is a unique position. Without any siblings to compete with, the only child monopolizes their parents' attention and resources—not just for a short time like a firstborn, but forever. In effect, this makes an only child something like a "super-firstborn."

In addition, only children have the privilege (and the burden) of having all their parents' support and expectations on their shoulders. Thus, only children tend to be:

  • Mature for their age
  • Perfectionists
  • Conscientious
  • Diligent
  • Leaders

What This All Means

Birth order personality traits are not set in stone. For example, you may have a youngest that has characteristics of an oldest or vice versa, and that's perfectly normal because every person is unique. But, awareness of how birth order tends to influence personality can help you be a better parent. So, if you notice your oldest being too hard on themselves or your middle is feeling neglected, offer up some encouragement and extra attention.


Does sibling birth order affect personality? ›

Birth order does not appear to influence personality in adults, according to several ambitious studies published in the past few years. This new wave of research relied on larger data sets and more robust statistical methods than earlier reports that claimed to find a relationship between birth order and personality.

Does birth order affect personality traits? ›

A 2015 study of U.S. high school students found no statistically significant association between birth order and intelligence or personality traits.

What causes siblings to have different personalities? ›

Q: Why are siblings so different? First of all, genetics can account for sibling differences. Siblings usually only share 50 percent of the DNA passed down from their parents. Second of all, even if siblings attend the same school, they may hang out in different crowds, which in turn influences their personality.

Do you think the first child in a family has different personality? ›

Firstborn Personality Traits

Firstborns tend to bask in their parents' presence, which may explain why they sometimes act like mini-adults. They're also prone to being diligent and wanting to excel at everything they do. As the leader of the pack, firstborns often tend to be: Reliable.

What is the eldest daughter syndrome? ›

Eldest daughters are responsible, dutiful, thoughtful, expeditious and caring. Firstborns are more intelligent than their siblings, more proficient verbally and more motivated to perform. Yet at the same time they seriously doubt that they are good enough.

What is the third child like? ›

Third born children are usually the charmers in the family. They become the class clown and are usually good manipulators. They are also affectionate and uncomplicated. Underneath all of that charm they can be rebellious, critical, temperamental, spoiled and slightly impatient.

How does birth order affect sibling relationships? ›

The study found that first-borns rated their relationships as more positive and prioritized family more than later-born siblings. The youngest siblings described their relationships as being the worst compared to first and middle born children. Evolutionary theory offers a possible explanation to these findings.

How does birth order affect children's personalities? ›

Does birth order influence personality? Firstborns tend be more conscientious, hard-working, responsible and assertive than their later-born siblings. As a result, firstborns are likely to be high achievers academically across fields ranging from politics to science.

What are the six characteristics of first borns? ›

In general, firstborn children have been found to be responsible, assertive, task-oriented, perfectionistic, and supporters of authority. Firstborns can harbor some resentment toward siblings because parental attention has to be shared.

Who is the middle child out of 4? ›

In such clear-cut scenarios, the middle child is simply the one born after the eldest and before the youngest. However, when it comes down to the abstract notions and effects of Middle Child syndrome, bigger groups of siblings may be affected as well.

What is big sister syndrome? ›

Children who are five years younger than their next oldest sibling usually display some oldest child traits, as do first daughters with an older brother, or first sons with an older sister. Twins, even though they never knew a time without a sibling, often take an “older” and “younger” position.

Why do siblings not have the same traits? ›

Because of recombination, siblings only share about 50 percent of the same DNA, on average, Dennis says. So while biological siblings have the same family tree, their genetic code might be different in at least one of the areas looked at in a given test. That's true even for fraternal twins.

What is the personality of the second child? ›

Second born children tend to “bounce off” the firstborn – or the child immediately ahead of them – often developing opposite traits of the firstborn. Because they look to their peers for acceptance, middle children tend to be sociable, friendly and peacemakers.

Who does the first child resembles? ›

Two other studies in Evolution & Human Behavior, one in 2000 and one in 2007, found that newborns actually look more like their mothers than their fathers in the first three days of their lives, as judged by unrelated assessors.

Why is the second child more rebellious? ›

Joseph Doyle, an economist from MIT in the USA discovered that second-born children are more likely to misbehave, and it's mostly to do with how their parents bring them up.

What is second daughter syndrome? ›

Second child syndrome or middle child syndrome is when the second-born or middle-born child gets uncomfortable with the presence of their siblings. It can be due to the lack of importance or attention when the parents give more attention to younger children and give responsibilities to older siblings.

What is golden child syndrome? ›

What is a golden child? "When people use the term 'golden child' or 'golden child syndrome,' they are referring to a child who has been deemed by their family—most often the parents—to be exceptional in one way or another, but without a foundation for the attributed exceptionalism," explains Smith.

What is the mother syndrome? ›

When this syndrome occurs, a divorced or divorcing parent seeks to punish the other parent, sometimes going far enough as to harm or deprive their children in order to make the other parent look bad. Though most commonly called Malicious Mother Syndrome, both mothers and fathers can be capable of such actions.

What is the hardest number of kids to have? ›

A survey of more that 7,000 mothers found that the least stressful number of kids is four, while the most stressful number is three. Scary Mommy blogger Jill Smokler told Today that she wholeheartedly agrees.

What is the best number of kids to have? ›

A 2007 study found that the majority of Americans believe 2.5 kids is still the ideal number of children to have, and six out of 10 Americans believe "smaller" families — with two kids or fewer — is the way to go.

Are people happier with 3 kids? ›

There are no appreciable differences in happiness for women with three or more kids; their levels of happiness are statistically indistinguishable from those of childless women. How can these differences be explained? It's obviously easier to care for just one or two children, so my results are counterintuitive.

What is oldest sibling syndrome? ›

Obsession, desire for perfection, high self-esteem, or pressure to meet parents' expectations are common signs of oldest child syndrome. Children with oldest child syndrome could show dominance and act as second parents to siblings.

Does birth order affect sibling rivalry? ›

New research has uncovered deep secrets hidden within the mystery of academic sibling rivalry. First borns were significantly more conscientious and also more dutiful than younger siblings. Last born siblings were more likely to feel academic rivalry compared to first borns.

How does being a middle child affect your personality? ›

Middle children have personalities that are often overshadowed by their other siblings. The older sibling is strong-willed, and the younger sibling is the baby, which leaves the middle child somewhere in-between. Their personality may be dulled down by their siblings, making them quiet and even-tempered.

Which birth order is most successful? ›

First-born kids tend to be leaders, like CEOS and founders, and are more likely to achieve traditional success.

What does being the oldest sibling teach you? ›

"First borns tend to have a greater sense of responsibility to others, are more empathetic, more observant of parental distress and want to fix and repair situations," says Klapow. "They also tend to have a deeper level of confidence from their 'home base.

How can birth order impact a child's attitude and behavior? ›

Studies have confirmed that without question, firstborn children are offered more individual and uninterrupted hours of their parents' attention, which may, in fact, allow for relatively greater gains in intelligence. Middle children are often described as being peacemakers.

Are middle children people pleasers? ›

Middle child

In general, middle children are somewhat rebellious people-pleasers with large social circles who thrive on friendships. They can also be the peacemakers in the family (which can frustrate the oldest and youngest children when looking for an ally).

How does being the youngest child affect your personality? ›

The Youngest Child - “The Baby”

Just as with the oldest sibling, the youngest child often feels special and has a unique place in the family. They tend to be more rebellious and attention-seeking, creative, social, outgoing, and have a sense of openness.

Why are first borns so special? ›

First-borns aren't just healthier or smarter, but also they score higher on “emotional stability, persistence, social outgoingness, willingness to assume responsibility and ability to take initiative.” The researchers ruled out genetic factors; in fact, they uncovered evidence that later-born children might be ...

Are middle kids the smartest? ›

Middleborns are just as smart as their siblings.

But a study by the University of Illinois published earlier this year found that firstborns' IQs are only one point higher, on average, than their younger siblings — a fairly negligible difference.

Why the middle child is the strongest? ›

No matter the situation, we're used to things not going our way. Therefore, the middle child is a resilient beast. We don't crumble under pressure (like the baby of the family), nor are we prone to getting a big head (like our older siblings). We're just strong and grounded AF.

Why is the middle child the most successful? ›

While middle children do tend to be neglected by their parents (and researchers), this actually benefits them in the long run. “They become more independent, think outside the box, feel less pressure to conform, and are more empathetic,” she explained.

What does a toxic sister do? ›

Toxic people, in general, do not own up to their actions and the influence they have on others. “Criticism, looking down on you, bullying, invalidating or gaslighting, and physical intimidation or abuse – all of it happens in toxic sibling relationships.”

What are 5 characteristics of the middle child? ›

5 characteristics of a middle child:
  • They're peacemakers and pleasers.
  • They're competitive.
  • They try to fit in.
  • They are independent and focus on friendships.
  • They act out to get attention.
21 Apr 2021

What is First Born syndrome? ›

From having undivided attention to competing for parents' love and affection, this drastic change often leads to developing a 'me first' syndrome in the first born child. He/she may develop an unhealthy competitive attitude, especially with the little sibling.

What type of siblings are more genetically similar? ›

Identical twins are the only siblings that share 100% of their DNA. Non-identical brothers and sisters share about 50% of inherited gene variants, which is why siblings and fraternal twins can be so different.

Who is your closest blood relative? ›

List of who your nearest relative is
  • Husband, wife or civil partner (including cohabitee for more than 6 months).
  • Son or daughter.
  • Father or mother (an unmarried father must have parental responsibility in order to be nearest relative)
  • Brother or sister.
  • Grandparent.
  • Grandchild.
  • Uncle or aunt.
  • Nephew or niece.

Can you inherit traits from your siblings? ›

Our genetic likeness continues to drop by 1/2 with each increasingly distant branch in the family tree. However, there's an important distinction -- while everyone shares exactly 50% of their DNA with each parent, we share on average 50% of our DNA with our siblings.

How second child is different from first? ›

Everything you need to know about your second pregnancy. Your second pregnancy is often different than your first. You might show sooner, feel more tired, have stronger or more frequent back pains, and notice Braxton Hicks contractions earlier. Labor will likely be faster, but postpartum recovery could take longer.

Is it better to have 2 sons or 2 daughters? ›

Having two daughters leads to the most harmonious family life, according to a study by the popular U.K. parenting website

What personality does the middle child have? ›

Characteristics of a Middle Child

They're good at being mediators and want fairness in situations. They're also trustworthy friends and work well as team members. Not as family-oriented as their siblings. They may have a stronger sense of not belonging than their siblings do.

Does first-born girl look like father? ›

There's no set genetic rule that all first born daughters look like their dads, but in many cases – thanks to TikTok – we've seen this theory proved. However, we think this is nothing more than a cute opportunity for Das to be involved with their daughters' TikTok careers.

What do daughters inherit from their fathers? ›

We inherit a set of 23 chromosomes from our mothers and another set of 23 from our fathers. One of those pairs are the chromosomes that determine the biological sex of a child – girls have an XX pair and boys have an XY pair, with very rare exceptions in certain disorders.

Do boys look more like mom or dad? ›

Y-chromosomes have fewer genes than X-chromosomes and some of them are responsible for the development of male genitals. This is why a boy is more likely to look like his mother. When it comes to girls, they receive X-chromosomes from both parents, so it's impossible to predict what they will look like.

Which sibling is usually the smartest? ›

Oldest children are the smartest, research shows

If you're the youngest or middle child in your family, get ready for some unwelcome news: Your eldest sibling is likely right when they brag about being the oldest and the wisest.

Which child is most likely to rebellious? ›

The between-family analysis showed the same effects as previous research—that middle children were about 33% more likely to exhibit delinquent behaviors than first-born children. Last-born children were about 20% more likely to exhibit these behaviors than first-born children.

Do mothers prefer their first child? ›

The truth is, research actually shows that favoring a child isn't all that uncommon. And, like Samantha, most parents will favor their oldest child. Birth order does influence how parents feel about their children, according to a study published in The Journal of Family Psychology.

How the birth of a sibling affects a child? ›

Difficulties with adjusting may express themselves a number of ways. Sibling rivalry sometimes starts right after (or even before) the arrival of the second child. Occasionally, the older child can become aggressive, “act out” or even regress, acting more like a baby.

How Being the oldest child affects personality? ›

“Firstborn children can be goal-oriented, outspoken, stubborn, independent, and perfectionistic,” Smelser says, and when you look at the way firstborns are nurtured, it starts to make sense why. “These traits are often reinforced by parents through their interactions with the child,” she says.

Does birth order affect MBTI? ›

Males and females do not exhibit significantly different MBTI types, and birth order does not affect personality much. However, an “only child” seems to have some personality differences compared to another person with siblings.

How does being the youngest sibling affect you? ›

Youngest children are also often described as spoiled, willing to take unnecessary risks, and less intelligent than their oldest siblings. Psychologists have theorized that parents coddle youngest children.

Which sibling is the most successful? ›

First-born kids tend to be leaders, like CEOS and founders, and are more likely to achieve traditional success. Middle-born children often embody a mix of the traits of older and younger siblings, and they're very relationship-focused.

Which personality type is the rarest in order? ›

INFJ is the rarest personality type across the population, occurring in just 2% of the population. It is also the rarest personality type among men. INFJ stands for Introversion, Intuition, Feeling, and Judging.

Who is the middle child of 4 siblings? ›

In such clear-cut scenarios, the middle child is simply the one born after the eldest and before the youngest. However, when it comes down to the abstract notions and effects of Middle Child syndrome, bigger groups of siblings may be affected as well.

Are first borns more likely to be introverted? ›

Firstborns are more likely to be introverts (+2.37%) according to our data, and the effect is especially pronounced when combined with Thinking (+3.04%) and Judging (+4.41%) traits.


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