Birth order and family dynamics
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First Born, Middle, Youngest, Only Child – What does it mean?

Birth order, one’s position in family, is one of the influences on personality development. How we each become who we are is an enormous topic. We are born with inherent traits and temperament (nature) and then life happens and we are influenced by our environment (nurture).

Birth order is not destiny, it is just one of many influences which include genetics, gender, and talents. But much of personality is formed in the early years when parents and siblings are primary influences on self-confidence, trust and the ability to interact with another person. When parents consider the possible effects of birth order they can better adapt their parenting to help children develop. I do not have any training as a psychologist, but I think you’ll find it interesting to see the basic personality stereotypes based on position in family.

Here are some qualities associated with each position in family.

First born

Personality tendencies:

Natural leader, ambitious, responsible, eager to please. Some studies show firstborns with 2-3 points more I.Q. than siblings (I know, just fuel to their bossy fire).

They tend to be reliable, conscientious, structured, cautious, controlling, achievers, diligent, competitive, dominant, and organized. I am a firstborn; we like to be in control.

Early life experiences:

Firstborns have the full attention of mom and dad for a while, without competition. When a sibling arrives, the first born often becomes protective – with a sense of responsibility. A firstborn is kind of a family experiment for new parents who are operating on instinct and trial and error. Parents are usually inexperienced and may not be confident. They may rigidly follow parenting guidelines. Parents have high expectations and as a firstborn grows up he/she will try to please them. If he/she feels like they disappoints them, they can rebel.

Personal note: I have been taking long walks (and talks) with a group of friends for 30+ years. We have only belatedly realized that we are all firstborns. I guess no one else would put up with us!

Birth order, middle child

Middle Children

Personality tendencies:

Peace-maker, fairness obsessed, social, an attention-getter with a mildly rebellious streak, negotiator and good at compromise. They do not like to be told what to do.

Early life experiences:

Middle children don’t have the rights and responsibilities of the eldest or the special position of the youngest. Parents are focused on eldest (experiment, first at everything) and the youngest (the baby). Middle children make their mark among their peers and rely on them. They tend to thrive on friendships and have large social circles.

Being a middle is complicated. If an eldest does not lead or take responsibility, the middle child can try to usurp the role. If there are several middle children, they may try hard to differentiate themselves from each other. (This is not always a pretty process for parents).

Youngest, The Baby

Personality tendencies:

Free spirit, charming, outgoing, risk taker, fun-loving, uncomplicated, manipulative, attention-seeker, self-centered, beloved, treasured, and tends to be less responsible than older siblings. Loves the spotlight and will wrestle it away from others. Will be the one organizing the show in which he/she stars. If they cannot keep up with older siblings and get ‘good attention’ with success and skill, they may deliberately fall down to redirect attention to themselves.

Early life experiences:

Parents are more relaxed and less cautious and protective than they were with the first born. They don’t have time to ‘over parent’. By now, they have embraced the ‘five second rule’ for eating food dropped on the floor. Some youngest resent being treated like a baby. They try to be responsible or social.

Parents often have more money than they did with the firstborn. They may have help and they may both be pursuing careers. They tend to be less rigid about rules and the youngest still gets lots of attention. When siblings have left the nest, the youngest may get all the day-to-day attention. When a friend’s two older children left for college, her husband memorably told her, “You might be an awful lot of parent for one child.”  Our household had a no TV during the week policy – then when I just had one daughter at home I used to beg her to finish her homework so we could watch Gilmore Girls together. Youngest children may be the most free-spirited due to their parents’ increasingly relaxed attitude towards parenting.

Only children

Personality Tendencies:

Only children can have the traits of ‘super firstborns’. Mature for their age, perfectionists, conscientious, diligent and leaders. They may need to be ‘model human beings’. They are usually comfortable with adults, and have a sophisticated sense of humor.

Early life experiences:

The only child monopolizes his parents’ attention and resources, not just for a short period of time like a firstborn but forever. To compensate, we know one father of an ‘only’ who deliberately behaved like a sibling, competing for the best cookie or the choice of radio channel in the car. Only children have the privilege (and the burden) of having all their parents’ support and expectations on their shoulders.


Twins are often described as a single unit – the twins. They can operate independently of birth order. They get special focus so they rarely have the middle child need to attract attention. There’s typically less competition between identical twins. Fraternal twins, however, behave more like other siblings.

Birth order, twins

Gap Children

If you have a gap of at least five years in between births, a reset begins in the birth order. A baby born with a five-year-old sibling is likely to adopt the traits of a first born. If there are several older siblings and then a 5+ year gap, the former youngest, now middle, may never shed the baby role.

Blended families

New siblings in a blended family can collide and personality traits which have already been formed will not be relinquished easily. Who’s the boss?


The age at which the child is adopted is a key factor in which traits the child is most likely to exhibit. They don’t give up being a first-born, they take the birth order with them into a new family.

Beyond birth order, here are some other influences on your personality development:


Biology is destiny. As much as half of each of our personalities may come from genetics. Despite your birth order you are born with the tendency to be shy, bold, daring, creative or outgoing. When a child’s biology runs into his or her birth order, and it can be stressful, especially for the eldest.


The truth is that parenting has an enormous impact on how any child develops. Parents are in a unique position of being able to nurture a child.


Siblings of different sexes automatically have gender as a way to distinguish themselves.

Size and strength

Older kids get bigger and stronger sooner, so they often dominate younger siblings in the early years.


Extraordinary talent or a disability tends to get even a middle child lots of family energy and attention, so their life experience can be more like a first born or a youngest.

Interval between siblings

Kids who are one or two years apart can compete with each other, particularly if they are the same sex. Parents can be at full stretch just keeping up with several young children, so there is not limitless energy and attention for each child. They can still be close when they’re older.

If there is a small gap between first siblings, the second child may vie for the firstborn role. Some experts say that a three to four-year gap tends to be a sweet spot for siblings. Kids are close in age but have room to be themselves.

Is personality fixed? Personalities are plastic and shapeable all of our life, but certainly children’s personalities are most flexible. A better understanding of the possible effects of birth order on our children will make us better parents. Understanding how our own birth order may have shaped us, will give us a better understanding of ourselves.


Do you need a little help with improving your sibling relationship? This ASE article will be good reading for you.

Adult Sibling Relationships – Are Yours Good?