Birth order and siblings: Pop psychology or reality?

Mrs Lyn Chakravorty, Head of Beanland House

SiblingsWhen visiting an American university in January this year, I became interested in Professor Susan McHale’s new body of work on the role of siblings in family dynamics. Upon my return to Brisbane, an article on first-borns, ‘Made for life: First out, best dressed’ (Symons, 2013), caught my eye. Birth order theories had been dismissed by many as pop psychology in the 1990s, but in 2013 rigorous debate still continues about this controversial theory. Is there really something to this birth order theory and could this new research about siblings help me gain a better understanding of my students — their personalities and academic performance — and about the role of sisters?

Birth order is fun to debate. Everyone is an oldest, middle, youngest or only child and can recount a personal story when it comes to birth order. We are all affected by this constellation but the effects of birth order are not straightforward and clear (Klass, 2009). Birth order theorists begin with the basic premise that every child born into a family assumes a unique position which determines his or her early experiences of life. Because the family unit is a microcosm of society, lessons about conformity, frustration, persuasion, strategy and control are learned from an early age. Theorists would have us believe that an individual’s intelligence, achievement, career, creativity, empathy, delinquency and even blood pressure are all linked to birth order (Hudson, 1990).


The interest in birth order and intelligence dates back to 1874 when Sir Francis Galton observed that more first-born sons held prominent positions than could be attributed to chance (Kristensen & Bjerkedal, 2007). Early in the twentieth century, Austrian psychoanalyst Alfred Adler argued that birth order has an effect on personality and that the position in the family — whether it be first-born, second, middle, only or youngest — leaves an indelible stamp for life (Grose, 2003). The publication of Frank Sulloway’s Born to Rebel in 1996 added renewed energy to birth order research. Given his belief that place in family was the single best predictor of leadership and creativity, Sulloway (cited in Grose, 2003) assigned the following set of personal characteristics to the different birth order positions:

  • First-borns are more: achievement-oriented, anxious, antagonistic, assertive, conforming, fearful, jealous, extraverted, organised, intense, responsible, self-confident and traditional. They are more likely to identify with their parents and more likely to assume leadership roles than later-borns.
  • Later-borns are more: gregarious, co-operative, easygoing, jealous, intense, adventurous, altruistic, emphatic, open to experience, popular, rebellious, risk-taking, sociable and unconventional. They experience more stress.

In Why First-borns Rule the World and Last-borns Want to Change It, Michael Grose (2003) questioned how a group of children from the same genetic pool, being brought up by the same parents in the same neighbourhood and attending the same school, could be so different. He also argued that, ‘A child’s position in his or her family impacts on the child’s personality, behavior, learning and ultimately his or her earning power’ (p. 1).

Not everyone, however, agrees with the conclusions of the birth order theorists. These studies have been criticised for focusing on outcomes or observed relationships and not on causation. In addition, when scientists scrutinised the data, they found the link between birth order and personality to be tenuous and not convincing (Hartshorne, 2010). According to Alan Stewart (cited in Whitbourne, 2013), we are not fated to live our life dominated by the timing of our birth. Having distinguished between birth order (the numerical rank order into which you are born) and psychological birth order (self-perceived position in the family), he concluded that one’s perceived niche in the family plays a larger role in influencing the adult we become than the actual timing of our birth. In addition, Daniel Eckstein (cited in Whitbourne, 2013) has argued that parents may, because of their perceptions about birth order, unconsciously assign these stereotyped roles and create self-fulfilling prophesies for their children. It is important to define our children in terms of who they are and not when they were born (Whitbourne, 2013).


These birth order theories cause a great deal of soul-searching on the part of parents. In trying to pin down the definitive shaper of a child’s personality, experts finally conceded what is obvious: that the one constant in family life is the parent. This central role often causes parents to feel guilty about their child-rearing decisions, particularly when they share their time unequally between siblings. Parents would certainly agree with the proposition that the first child could be thought of as ‘the first draft’ (Whiteman, McHale, & Crouter, 2003). Experience helps, making parental expectations about adolescents more realistic and leading to more relaxed and harmonious relationships with later-borns (Whiteman, McHale & Crouter, 2003). It must be acknowledged, however, that parental supervision, attachment and discipline are also significant influences on each child’s development (Cundiff, 2010).

Recent studies have concluded what we have known all along: siblings are key players in forming a child’s personality. Parents raise you. Your spouse lives with you. But it is your brothers and sisters who really shape you (Kluger, 2006). It is from siblings that lessons are learned about how to form adult relationships. From birth, siblings perform quite contradictory roles; they are competitors yet objects of pride, both collaborators and co-conspirators, role models and cautionary tales, protectors and scolds, tormentors and playmates, counsellors and sources of envy. They teach one other how to resolve conflicts, how not to conduct friendships, and when to walk away from them. Sisters teach brothers about the mysteries of girls, brothers teach sisters about the puzzle of boys (Kluger, 2006). Professor Susan McHale (cited in Kluger, 2013) believes that, ‘There’s nothing like having a band of brothers and sisters to venture out with you’. Dorothy Rowe describes in My Dearest Enemy. My Dangerous Friend: Making and Breaking Sibling Bonds (2007) the pain and pleasure of having a sibling and how sibling relationships are very much about being validated as a person. Siblings themselves go a long way to explaining sibling dynamics and individual personalities within families.

To gain personal insights into what being a sibling means for today’s teenaged girls, I asked several Grammar girls for their thoughts.

First-born siblings

As the oldest child, I am used to doing things first; I remember that being the first to go to high school made me feel so grown-up. When my sister came to Girls Grammar, I became a bit competitive… I think it was a bit of sibling rivalry, although she always seemed so chilled…

As the oldest sibling coming to Girls Grammar, you get to find out everything for yourself, which is more fun! On the other hand, it means that my sister has (hopefully) been able to learn from my mistakes.

Second siblings

As the second sibling to come to Girls Grammar, I found it both easy and difficult. Arriving in Year 8 wasn’t daunting or overwhelming but exciting… [but] it was slightly more difficult to pave my own way and make my own impact on the School.

Being the second child to come to Girls Grammar I found it hard not to copy my sister all the time. I found that I have similar interests to her but I don’t want to copy her every move.

I felt as though everyone expected me to achieve the same sort of standards academically as my sister. I don’t really feel that pressure anymore, as I have found different strengths in different subjects to what she did.

I realised before I came to Girls Grammar how different we were, and I think this was a good thing, because I think I would have felt pressured to ‘match’ her in some ways. I really appreciate my sister’s advice but I am at a point now where I just want to discover things on my own.

Third siblings

While being the youngest also meant that there were expectations for me to reach the standards of my sisters, it was ultimately easier, as I had people who had experience and were able to pass that and their wisdom on to me.

As the third and youngest child in my family, I generally found my transition into high school easy and comfortable. From the beginning, I was already equipped with experiences from my older siblings, which granted me a certain degree of mental preparation. It was a great advantage.

The consensus amongst Girls Grammar students surveyed is that siblings are significant figures in their adolescent lives. Being the trailblazer is exciting and actually fun, and the older siblings are willing to support and encourage their sisters. As a result, younger siblings are more relaxed and comfortable with school life because they have learned from the experience of their older sisters. These second and third siblings, however, seek to differentiate themselves, staking out their own identities, strengths and co-curricular interests, ever conscious of parental pressure to achieve the same standards as older siblings.

In conclusion, a generation of researchers has tried to prove that birth order determines each child’s personality. Certainly no adolescents, especially later-borns, like to be typecast by random factors such as their order of birth. It is unwise to use our perceptions of birth order to stereotype children, because other factors, such as family dynamics and siblings, determine their character. At Brisbane Girls Grammar, teachers try not to make assumptions about birth order and siblings. Girls are seen as unique individuals in their own right. Siblings are not identical clones, despite having the same genes and family background. They are valued simply for themselves.


Cundiff, P. (2010). Ordered Delinquency: The effects of birth order on delinquency. (Master of Arts Thesis, Pennsylvania State University). Retrieved from

Grose, M. (2003). Why first-borns rule the world and last-borns want to change it. Sydney: Random House.

Hartshorne, J. (2010, January 11). How birth order affects your personality. Scientific American. Retrieved September 20, 2013, from

Hudson, V. (1990). Birth order of world leaders: An exploratory analysis of effects on personality and behavior. Political Psychology, 11(3), 583–601.

Klass, P. (2009, September 7). Birth order: Fun to debate, but how important? The New York Times. Retrieved September 20, 2013, from

Kluger, J. (2006, July 2). The new science of siblings. Time, pp. 1–4.

Kristensen, P., & Bjerkedal, T. (2007). Explaining the relation between birth order and intelligence. Science, 316(5832), 1717.

Rowe, D. (2007). My dearest enemy, my dangerous friend: Making and breaking sibling bonds. London: Routledge.

Symons, E. (2013, February 16–17). Made for life: First out, best dressed. The Weekend Australian Financial Review, p. 53.

Whitbourne, S. (2013, May 18). That elusive birth order effect and what it means for you. Psychology Today. Retrieved September 20, 2013, from

Whiteman, S., McHale, S. & Crouter, A. (2003). What parents learn from experience: The first child as a first draft? Journal of Marriage and Family, 65(3), 608–621.

Published Thursday 17 October 2013

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