I was more than a little shocked when Steven Pinker stated point blank that birth order does not affect personality. It was a little more than a page or two in his long The Blank Slate, but it was the part that most stuck with me. Not long after reading that, I came across a chapter collected by Gary Marcus making the same argument. In essence, the argument was that study after study had failed to find any empirical evidence of birth order effects.
(Full disclosure: I have known Gary Marcus for some time, and his early work was a spring-board for my first published paper. I have met Pinker only a few times, but he was the PhD mentor of my first cognitive science mentor, Michael Ullman.)
I didn’t believe a word of it. But, as they say, “them’s the results.” There has been some success in finding a birth order effect on IQ, with IQ dropping a little with each child. A recent mammoth study replicating these results got a great deal of press. Still, that’s not really an effect on personality, which is what interested me.
This is not as esoteric a point as it may seem. There is a lot riding on it. The reason Pinker brought up birth order in his “The Blank Slate,” was that it is a test case in the Nature vs. Nurture debate. Specifically, what affect do parents and the familiiy environment have on children as adults? That’s a hard question to test, because it’s hard to quantify “family environment.” But birth order is easy to quantify. Pinker argues that family environment and parent child-rearing strategies are fairly irrelevant. The lack of birth order effects on personality lends strong support.
As I read the literature on birth order effects, I started to wonder if the problem was with quantifying “personality.” These studies all hinge on having a good measure for “personality,” otherwise you can’t say that people of a similar birth order are similar in personality. I began to think I had a way around this problem, and I developed an experiment. I ran two versions of the experiment on undergraduate psychology students at Central Michigan University, and it showed weak but significant birth order effects. Undergraduates at a single school is a fairly limited sample, so I’m running a larger version of the same experiment through the Web.
You can participate by clicking here: Birth Order Study.
In a few weeks, I hope to do a more detailed post on this topic.
I’ll be interested in seeing what you come up with.
Personality is such a nebulous thing.
My review of Pinker’s The Blank Slate might be of interest to some of your readers. I guess the statement you cite came from the second part of the book–the good part in my estimation–once he gets past a long rehash of academic squabbling and gets to his original ideas. In that part, he has lots of interesting speculation with some research support but largely open questions.
Fred Bortz — Science and technology books for young readers (www.fredbortz.com) and Science book reviews (www.scienceshelf.com)
Waiting for your results
For wealth of Science facts visit : http://sciencefacts.articlemuseum.com/
Hey, Im a teen from Darwin, Australia. Read your article, I’ve read the Blank Slate too, didn’t get much of it, but I er, enjoyed it, felt like I knew heaps more, but I want to read more. Anyway, the dealio is, I was wonder what sort of personality I had, Im a single Child born last in a family with 3 older step brothers who I rarely saw, step brothers belong to my mother.
ps: would there pasts effect my personality? or would there pasts effect my personality if they talked to me about it to set and example
mk no worries bud. keep up the nice blog, Im a fan now
Your case is a very interesting one: how do siblings affect you if you don’t actually see them? It depends on how birth order effects work. Is it an effect on you? Is it maybe an effect on your parents? We all know the stereotype that parents obsess over their oldest child, but by the time the youngest comes around they figure the kid will turn out fine no matter what.
I know that Adlerians talk about “psychological birth order,” in which case they would consider you to be an only child. In large families of 6 children, they might split it into two smaller “families” of 3 and 3, if the oldest three and youngest three tended to hang out separately. But I don’t know if there’s any empirical evidence backing up that story.
However, the Scandinavian study that was just released a few months ago might have data that is related to your question. You should look it up…
Please try my web-based experiments at http://coglanglab.org
hey there
i was just wondering
what kind ofpersonality do i have?
i am the oldest child and i have two siblings
a sister whos the middle child and a younger brother
im the oldest by five years
would the results be affected by the fact that theres a history of substance abuse and alcoholics in my family?
Well as i just found out that i am the 7th child and im the yougnest. what is wrong with me, im so shorter than my other siblings and im way younger. They all have bigger shoes sizes than me.
i used to be an only child, then my mom got re-married now i have a little sister. i am eleven years older than her. so i still don’t know what personality i have. also my cousin lives with us, and he could be considered the middle child so….yepp (:
i am confused.