Birth Order Study: Siblings



imgresAttention all you brothers and sisters out there.

Chances are you’ve been swayed to consider birth order as the be-all and end-all influence on your personality.  You know, if you’re the oldest sibling, you are super responsible, more conservative.  If you’re the middle child, you like to please.  If you’re the baby, you’re spoiled, sociable.

Surprise!  The findings of  a study conducted by the University of Illinois at Urbana-Champaign and published in 2015 confirmed that, yes, there are indeed differences in personality and IQ associated with birth order, but that the differences are so small as to have no practical impact.

“You wouldn’t notice these differences by talking to a firstborn and a later-born who are the same age,” said Rodica Damian, lead author of the study, an assistant professor of social psychology at the University of Houston.

A slew of books have perpetuated the so-called birth-order effect.  When I wrote The Sibling Connection, the experts I interviewed and the majority of studies I reviewed, debunked the birth order myth.  Yes, it counts for something, but there are a host of other factors that help shape siblings and the adults they become:  gender, growing up with all boys or all girls, age spacing, family pattern over generations, parents’ attitudes, societal expectations.

Taken alone, birth order is is no more predictive than your astrological sign.

The Illinois study examined data on 377,000 US high school students. The data was detailed enough to allow researchers to control for factors such as number of siblings, socioeconomic status, family structure, age, and gender, which some researchers believe may have skewed the results of past studies.

As reported in her Boston Globe article, “Does Birth Order Affect Your Personality?,” Ami Albernaz writes:

Among the slight personality differences the researchers found, firstborn children were more conscientious and agreeable, and less sociable and neurotic, than later-born kids. Yet though these differences were statistically significant, they were so small as to be meaningless, the researchers wrote. Firstborns also had slightly higher IQs, but this difference — about one point — was also not enough to be perceptible.

Debunking the birth order myth will not be easy.  The concept has dominated discussions about siblings since 1961 When Walter Toman got the theory off and running in his book, Family Constellations: Its Effects on Personality and Social Behavior.  (Toman also has portraits of the male only and female only child.)

You can do your part to set the record straight: When someone asks, “Are you the oldest, middle child or oldest?,” suggest that, sure, they can make some assumptions, but that chances are good that you are so much more.




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Siblings: Myths v. Facts

Siblings:  Myths v. Facts

Almost eighty per cent of Americans have at least one sibling.  For the other twenty per cent, there is often significant curiosity about what life would be like with a sibling.

Yet with all the interest in brothers and sisters, it has only been in the last three decades that life’s longest-lasting relationship has been given its due.  Prior to the late-1980s, counselors, educators and siblings themselves never spent much time, if any, looking at the many ways siblings may have shaped each other.

Even today, with the expanding interest in brothers and sisters, there remain myths about the relationship that need to be debunked.

So, here are a few:

MYTH:  By the end of childhood, sibling relationships are set in stone.  There is little that can be done to salvage a frayed connection or to undermine a close one.

FACT:  The sibling relationship is fluid, ever changing.  There is always time and opportunity to bridge disagreements.  Predictably, there are events that can either bring siblings closer or split them apart, events such as marriage, children, the illness/death of a parent.

MYTH:  More than any other factor, birth order influences who siblings are and why they do or do not get along.

FACT:  Birth order is no more predictive than astrology when it comes to defining sibling relationships.  Yes, birth order matters but so do many other factors like gender, age gap, and generational models.

MYTH:  The closer in age, the less competition between siblings

FACT:  The jury is still out on this one.  There is evidence to support this theory and evidence to support the theory that having children too close leads to unnecessary competition.

MYTH:  The best way to handle sibling rivalry is for parents to jump in as quickly as possible and stop the quibbling.

FACT:  Research has shown that the more parents try to settle quarrels between their children, the more siblings fight.  When parents send their children to “separate room,” they don’t learn how to make deals, to compromise.  Quarreling between siblings can be quite healthy.

MYTH: Siblings have little, or no, effect on each other’s choice of profession.

FACT:  False.  Siblings may choose a profession very different from that of their siblings in an effort to carve out a separate, unique niche.  Or a sibling who grows up in an active, often noisy household may opt for a job where there is constant activity and people working together.  Conversely, growing up in a more “laid back” household may groom a sibling to work independently.

MYTH:  A majority of brothers and sisters say their siblings’ marriages enrich their relationships.

FACT:  Just the opposite:  In one of the few studies of young-and middle-adult siblings, two-thirds of those interviewed said the marriages of their siblings detracted from their relationship.  They felt their sibling had “married down.”  Or they simply didn’t like a sibling’s spouse or were not liked by him/her.

For books about siblings, check out:



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For Parents: Factors That Shape Your Children

In books about brothers and sisters, a lot is made about birth order.  The problem is: most studies have failed to show that the order in which children are born affects who they are.

Birth order is not so different than your children’s astrological sign.  You may find some characteristics that match and some that don’t.

Don’t get me wrong: birth order is a factor in who you children are and their relationships outside of the family.  But it’s only one of many factors.

So, what are other factors that shape your children?

  • Gender – Children learn a lot from a sibling of the opposite sex:  more about the “feminine” and “masculine” roles; how to love and not to love; how to quarrel and make up; self-esteem
  • Age spacing – There is evidence to support the benefits of children close together in age, and evidence to support the benefits of having children further apart.  The following article provides some of the pluses/minuses of close age spacing and some of the pluses/minuses of more years between the birth of one sibling and the next.
  • From generation to generation – Family patterns can be handed down from one generation to the next.  Your children and you are, in part, products of your ancestors and their patterns of behavior.  An example: A woman whose father and three siblings immigrated to the United States and had one another’s “back.”  Their close relationship served as a model for her and her siblings.  So, pay attention to how you and your siblings interact and how your parents and their siblings interact.  Your children are watching.
  • Gender preference – In both Western and Eastern cultures, boys are still valued more than girls.  In these cultures, boys are taught that they are superior to their sisters.  And girls are taught to accept this preference and their inferiority.  You can imagine how this setup can affect relationships between your male and female children.  When girls and boys are both valued and encouraged to explore their potential, they not only excel but so do their connections with their brothers and sisters.
  • Expressing emotions – Expressing emotions tends to run along ethnic lines.  People living in or from Mediterranean cultures tend to express their emotions more freely than people from non-Mediterranean cultures. Trouble can brew when your children and other family members are not encouraged to say what they feel.  The end results can be indirect aggression because feelings get bottled up inside.

Putting It All Together

The next time someone comments on the birth order of your children, you may want to suggest that, yes, birth order is a factor that helps shape your children but that there are many other factors that influence your children’s personalities and how they get along with one another.



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