When she was younger, my daughter used to beg me to tell her stories about my life as a big sister

“Tell me about Uncle Bran and the time he thought he could fly off the roof! Tell me about the time your brothers put chips on you when you were sleeping at the beach and you woke up with seagulls all over you!” she would say, eyes wide with anticipation. “Tell me about when Aunt Lexi was little and had that imaginary friend named Miss Nanny and Miss Nanny locked you out of your house!”

For my only-child daughter — someone who has never known the joys and sorrows and “I’m going to strangle you right nows” of having a sibling — these stories were on par with Grimm’s fairy tales. They were entertaining, but completely out of touch with her reality.

And as much as she loved hearing about my days as a bossy older sibling, she never longed to be a sister herself. “No. Ugh. I don’t want some baby drooling all over my toys,” was the answer she gave during her early elementary school years when I asked, “Do you think you’d want a little brother or sister?” Nowadays — she’ll be a seventh-grader in a few weeks — her answer is only slightly different. “You’d probably make me baby-sit. For free! No way!”

At the age of 12, my “only” is mature and confident and enjoys spending time alone with her artwork and thoughts. She is a fun travel partner and can hold her own in conversations with adults. It’s a quiet, serene life compared to our friends who have two or more children. Still, I often worry that I’ve messed her up by not providing that unbreakable sibling bond. Would she be affected by her only child status? Would she turn into a self-absorbed adult who can’t deal with other people’s idiosyncrasies or stomach the sight of baby drool?

Turns out — as with most things in life — I shouldn’t worry so much.

Although the general public tends to believe that birth order has definite consequences later in life — that first-borns are natural leaders and that the youngest child will be spoiled and needy, for example — much of the research on birth order and its effects on personality is vague and inconclusive, with many studies failing to account for factors such as blended families, a gap of more than five years between siblings, the death of a child, children born with mental and/or physical disabilities, a changing population that discourages large family sizes, adopted children, and a child’s gender, which are all factors that skew research on birth order and its effects on personality.

“Until very recently, there were no convincing findings that linked birth order to personality or behavior,” writes Harvard birth-order researcher Joshua K. Hartshorne in a 2009 Scientific American article on birth order and its effect on personality.

However, that doesn’t mean that everything we think we know about first-borns and only children is complete bunk. In fact, new research has revealed some interesting connections between birth order and the people we let into our inner circle of friends and partners.

Hartshorne and his colleagues found evidence that we are more likely to hang out with people who have similar birth orders. Middle children hang out with middle children. First-borns with first-borns, etc. This explains why the vast majority of my daughter’s friends also are only children. Something inside of us recognizes that our position in the family helped shape who we are and we look for similar traits in our friends and lovers.

“The evidence seems to be shifting back in favor of our common intuition that our position in our family somehow affects who we become,” Hartshorne writes.

Likewise, in a review of 200 birth-order studies, researchers found that, despite a lack of conclusive proof that birth order definitely shapes our personalities and behavior, there are common traits among the birth order positions. For instance:

  • First-born children tend to be more mature, highly motivated, confident and likely to lead. On the downside, they are also more vulnerable to stress, more fearful in new situations and prone to narcissism.

 

  • Middle children — classified as all children who are not first-borns or the youngest child — show the fewest signs of “acting out” behavioral problems, are more likely to be sociable and tend to be the most faithful in monogamous relationships. However, this study also showed that “middles” are more likely to feel as if they don’t belong.

 

  • Youngest children are more artistic, agreeable, popular and have high self-esteem. Of course, they’re also more likely to be rebellious, become an alcoholic and develop a psychiatric disorder.

 

  • Only children — and this includes youngest children when there is more than 7 years in between the siblings — are more likely to attend college, be likeable, cooperative with others, be more trusting and identify strongly with their gender. On the flip side, only children are also more likely to have behavioral problems and be selfish.

 

Does this mean that every only child will be selfish and every middle child will feel lost in the world? Of course not. But using these “common traits” as a guide can help you better understand yourself, your children and your partner.

Recently, my daughter and I tag-teamed on a babysitting assignment that included three sisters under the age of 10. The day was fun, but exhausting, with lots of power play going on between the three siblings. When we got home that evening, my kiddo looked at me and said, “I need to go be alone. I’m so happy that I’m an only child. Thank you for not having any other babies, mom!” And, with that, she retreated to her bedroom and reveled in her baby-drool-free stuff.

Want to learn more about birth order and its possible effect on your relationships? Check out these articles, books and sites:

“That Elusive Birth Order Effect and What it Means for You” May 18, 2013 Psychology Today

Born to Rebel by Frank J. Sulloway

“The Birth Order Effect” July 5, 2012 Psychologies

Information on birth order from the Child Development Institute

The Alfred Adler Institutes’ “Overview of Birth Order Characteristics”

“Why First-Born Kids Do Better in School” October 31, 2013 Slate

Information about birth order from PBS Kids