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How Does Birth Order Affect the Development of a Child's Personality?

With so many child-rearing guilts hanging over your head, let’s add one more—the order in which you gave birth to your children. (Does it ever end?) The scientific community has flip-flopped back and forth for decades on birth order and whether or not it plays a role in child development. According to Joshua K. Hartshorne, post-doctoral fellow at MIT and researcher of cognitive and language development, it may—or may not. “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 comments in a 2010 article in Scientific American. But in his 2012 blog in GamesWithWords.org, he concedes that it is still a "hotly-disputed topic." In an interview Hartshorne explained, "Briefly, we have very little direct evidence that birth order affects personality. Unfortunately, much of the published research is confounded." (Confounded is probably the operative word here.) In other words, the scientific community thinks your child’s personality "might" depend on if he’s the oldest, youngest or somewhere in between.

No. 1 Son ... or Daughter

Your firstborn. I’m sure you can recall every last moment of labor, her exact time of birth, the date she first walked, talked and slept through the night and the oodles of pictures. Did you know that by being your number one child you may be raising a natural leader—or the smartest one of your kids? "There has been some work on intelligence," Hartshorne says. "A couple years ago, I thought that it was firmly established that older birth order have slightly higher IQ, but ... this is now a lot less certain."

For those who do stand by the belief that birth order matters, firstborn children have dominant, sometimes aggressive personalities who try very hard to be model children although the sass at the supper table may not lead you to believe you are raising the next leader of the free world. They also tend to be less accepting of new concepts, yet may have a more conscientious attitude than your other children. (Attitude yes, conscientious—the jury’s still out.) And if your little darling is an only child, you may be raising a perfectionist.

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Down the Middle

Catharine Salmon, associate professor in the Psychology Department at the University of Redlands in California and co-author of the book The Secret Power of Middle Children, notes that the evidence suggests that birth order does indeed have a significant impact. If your young one is middle-born, you may see some distinct characteristics of this often misunderstood birth placement—at least according to many middle-born adults. Pam Laidlaw, a land developer, entrepreneur and second born in a family of three girls, remembers, “I always seemed to be overlooked. My oldest sister always got the praise, and my little sister always got the attention. I don’t remember ever seeing any photos of me when I was a baby unless I was propped on my older sister’s lap.” And so it goes for your middle child or children. Middle-born tend to feel left out and may be somewhat secretive because of it. They may act as the peacemaker between your oldest and youngest and may even feel lost in the shuffle, especially if you have more than one middle child. Laidlaw recalls with a grin, “Even before I started school, I remember getting my other two sisters in trouble and just walking away. Not being noticed sometimes had its advantages.”

End of the Line

If you have several children, I’m sure you’ve heard this melodic sing-song at one time or another about your youngest: “You love her more than us. She’s spoiled!” And they might be right—about the spoiled part, that is. The baby of your family tends to be more taken care of and protected than the rest of your kids. She may be charming, even manipulative (Not my little darling!), and she loves to be in the thick of things. From a very young age she loves attention and may be a social butterfly among the playground set with a tendency to be extroverted.

Your Role in the Lineup

As you get older and your circumstances change, so does your parenting style. Your first child is an experiment in child rearing; the second is a bit more casual and relaxed. By the time the rest come along, you’re an old hand at it. There are many other developments in your life, such as jobs, cash flow, marital status and your age that also influence your child’s personality. And in regards to your role in all of this, Hartshorne writes, “There are many reasons that family size could affect our predilections and personalities. More children mean that parental resources ... have to be spread more thinly.” The jury is still divided but with a definite lean towards birth order as a major force in your child’s personality development. But for once you can honestly say there isn’t much you can do about that.

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