How your Birth Order Might Influence your Personality

It may seem a bit irrational to pay attention to things like birth order when reflecting on your personality. There isn’t a lot of science backing up its impact.

However, some psychologists including Dr Kevin Leman, author of The Birth Order Book: Why You Are the Way You Are, believe that birth order is the reason for sibling personality differences. That school of thought says that if parenting is predictable, then we will reliably emerge with certain traits. 

This posts looks at some typical traits observed in the first, middle, last born, and only child. The point is to raise your awareness of how your position in the family might still be affecting who you are as an adult. 

First born

As a first born, usually you are lavished with undiluted love and attention. In theory, you benefit emotionally from that, emerging from childhood with a secure sense of your position.

As a first born, you are also forced into a position of leadership and responsibility. The challenge for the first born is bearing the weight of adults’ great expectations; a lot is riding on them to ‘get it right’. This emotional landscape might create in you an achiever mindset.

First born typically experiences the burden of expectations and responsibility Click To Tweet

As a first born, you apparently excel at wining the hearts of elders. There could be an element of perfectionism there, of wanting to be the best, that lasts well into adulthood.

In the event of a younger sibling, then you naturally experience a loss. Not only do you need to share, your life is intruded upon by a more primitive soul. And frustratingly, the threshold for your behaviour remains high though, as usually you’re required to ‘set an example’.

Despite the irritations, you receive an early lesson in nurturing a younger sibling. As an adult, the experience probably helps you to love and to be sensitive to other people’s needs.


Typical traits of first, middle, last and only children:

First and only born: Reliable, conscientious, structured, cautious, controlling, achievers.

Middle children: People-pleasers, somewhat rebellious, thrives on friendships, has large social circle, peacemaker.

Last born: Fun-loving, uncomplicated, manipulative, outgoing, attention-seeker, self-centered.


Second or middle child

The struggles and insecurities of the middle child are well accounted for – we are the only ones that have a syndrome named after us!

As a middle child, you have trouble finding your place, identity and significance in the family unit. Middle children are generally more socially inclined, and place a greater value on friendships. They are more likely to find ‘families of choice’, which might be a compensatory ploy to get over the lack of attention received in the family unit.

Middle children are also often cooperative and competitive at the same time and concerned with fairness. 

Middle children are usually (over) preoccupied with fairness Click To Tweet

As a middle child, you often develop quicker, seem smarter and more capable due to the benefit of watching the first born mess up. But you might also feel feelings of inadequacy, as you notice but don’t understand why you ‘lag behind’. 

Ultimately, you can develop a ‘where’s mine?’ attitude, feeling jealous and left out. This emotional territory can negatively affect adult relationships.

Middle children often push the envelope the most, compared with the other siblings.

Last born

The last born feels almost none of the parental anxiety. Parenting is usually a lot more relaxed and that contributes to your personality. 

As the last born, you have greater freedom and autonomy. If parenting is predictable, the last born child is the most entitled, independent and self-referential.

The last born is often the most entitled and self-referential Click To Tweet

Because of the leniency, last born children are the most free to choose their path creatively. They may have an easier time finding the right career or partner.

Only child

Only children are like a ‘super first born’. Without any siblings to compete with, they monopolize parents’ attention and resources. As an only child, you never have to play second fiddle to anyone.

Only children have the privilege (and bear the burden) of having all their parents’ support and expectations on their shoulders. Therefore as an only child, you tend to be mature for your age, perfectionist, conscientious and diligent.

Even when only children reach adulthood, they may not necessarily shed their need to be model human beings.

Summary of birth order impact

As a middle child but also the first girl, I recognise myself in the typical traits of both the first born and the middle child.

When I look at my brothers and I, I can see the legacy of our positions living on in our lives. My older brother is probably the most burdened by the weight of the world. My younger brother does seem to have a natural confidence stronger than that of myself or my older brother. And I have tended to be the wildcard middle child, my actions reflecting the insecurity I have felt. 

As adults, knowing our potential birth order impact helps us to observe when we might be distorting reality based on that legacy. 

Here’s how you might want to parent yourself now based on the emotional legacy of your birth order:

  • First born/only child – lighten your load. 
  • Last born – develop discipline and responsibility. 
  • Middle enough – give yourself reassurance that you are loved and you matter. 

If you are interested generally in what shapes your personality, I’d really recommend reading this article about the Enneagram.