The Birth Order Effect

By: Bella Dalba

            The enduring theory of birth order is, unsurprisingly, a commonly-held belief amongst families. The majority of people subscribe to the notion that the order in which they and their siblings were born correlates directly to the person they ultimately become. The thought does present an interesting notion: since only children are quite easy to differentiate from those with siblings, shouldn’t the differences between siblings be recognizable? According to the pop culture belief, whether you’re a domineering first-born, restless middle child, or the infamously stubborn baby, your position within the family can affect everything from your choice of career to how successful your marriage will be.

 

            The importance of birth order was first set out by the Austrian psychologist Alfred Adler. Michael Grose, an Adlerian-trained parenting expert and author of Why First-borns Rule The World And Last-borns Want To Change It, explains the basics. “We’re in a Darwinian struggle from the moment we’re born, fighting for scarce resources within a family – our parents’ time, love and affection,” he says. Through human evolution, birth order has determined who inherits power (the first-born) and who is sent to war (the youngest as he was the ‘spare’).

            Psychology goes through periods of alternatively accepting and rejecting these myths. Although various theories have been created, the discerning factor between them is the right research approach. Of the many factors to control, there are even more that cannot be: the sex of the children, the number of years between them (in multiple-child families), and family history, but what about step-siblings, half-siblings, and siblings who don’t even know that the other one exists? Parents vary in their ages, and in the ages they were when they had their children.  When it comes to psychological variables, the situation becomes even more complex. Do we study actual achievements, and, if so, how do we measure them? Income? Education? Occupational prestige or advancement in their career?  Should we look at personality, motivation, intelligence, happiness, or mental health?

             Three familial order studies have been conducted in the past three years, the most important of which was the distinguished University of Georgia psychologist Alan E. Stewart, who wrote what is perhaps the definitive recent work (2012) on the theory and research on birth order.  He bases his paper on 529 journal articles published over a 20 year period.  The sheer number of studies on birth order is a testimony to the importance of this topic in psychology.

Taking his lead from the original birth order theorist, Alfred Adler (a one-time student of Freud), Stewart distinguished between “actual” birth order, or ABO (the numerical rank order into which you are born in your family of origin), and “psychological” birth order, or PBO (self-perceived position in the family). Your actual birth order need not have the same impact on you as the birth order you believe you have. Actual and psychological birth order can deviate for a number of reasons, including illness of one child, size of family, and degree of separation between siblings.  Your role in the family based on your age may not be same as the role you have come to occupy. Seckman junior (and prominent philosopher) Dominic Dalba agrees: “It is the people around us that ultimately shape the person who we become -- the environment we are raised in determines our personality, not the lottery of birth order.”

For decades following Adler’s writings, researchers working in the tradition of “individual psychology,” or the Adlerian school of thought, tried without much success to validate the theory. In part, this was because they lacked statistical methods available now, but also because they focused on ABO (i.e. actual) rather than PBO (i.e. psychological). Much of this changed when the Psychological Birth Order Inventory (PBOI) was developed in 1991 by a research team that included Stewart. The PBOI contains items to assess all birth order positions in the family that individuals rate on an agree-disagree scale.

Firstborn items on the PBOI tap feelings of being powerful, important, leading, and achieving (“It was important for me to do things right”). The middle-child items focus on competition, having fewer resources, and feeling unimportant (“It seemed like I was less important than other members of my family”).  For the youngest child items, individuals rate themselves on being the boss of the family, getting others to do things for them (“I was pampered by my family members”). Finally, the only child scale tapped those feelings of pressure (“I felt like I lived in a fishbowl”). Seckman junior Orion Zmashenski agreed: “As the only child, it’s kind of like that you’re your parents’ only hope. That’s a lot of pressure. But all the attention makes you feel adored, and you know that they will always be there for you (because there’s no one else to share them with).”

            Stewart’s study shows that your perceived niche in your family plays a larger role in influencing the adult you’ve become than the actual timing of your birth. We’re not fated to live out a life dominated by the accident of the timing of our birth, but you can change the way you think about your role in the family.