I recently devoured the novel Gone Girl (go read it, quick! it’s amazing!) and was struck by some early dialogue. A man’s wife has gone missing, the house shows signs of a struggle, and about 3 hours later he talking to the police. She doesn’t have any friends that he knows of in this small Missouri town they’ve moved to, and her family is back in NYC. When the detectives arrive, they ask if he’s called any of his wife’s family or friends, anyone at all, since he found her gone. He says no, he was waiting to talk to them before doing anything. One of the detectives say to him, “Just a guess of mine, why you’d wait for us: You’re used to someone else always taking the lead. That’s what my little brother is like. It’s a birth order thing.” This assumption of hers, that he was waiting for someone else to take control of the situation because he was low in a sibling hierarchy, hit me upside the head. I do the exact same thing, and I am the 6th of 6 kids. When I’m in a group situation, I almost always sit back and wait to see what direction the group decides to take or what consensus it’ll reach. The more people that are involved, the less I attempt to steer the conversation or have any influence. Obviously, some people have the opposite impulse, and naturally try to manage the group dynamic. Anyway, this tidbit got me all interested: oh great Birth Order Oracle, what else can you tell me about myself? Here’s the thing, though: the dude whose wife is missing wasn’t the youngest sibling. He was a twin, 1 of only 2 siblings total. And most birth order research is radically unreliable; offering for the most part only affirmation of what we all assume. Here, let Scientific American explain it: “until very recently there were no convincing findings that linked birth order to personality or behavior. Our common perception that birth order matters was written off as an example of our well-established tendency to remember and accept evidence that supports our pet theories while readily forgetting or overlooking that which does not.” (Confirmation bias, the dear friend of horoscope readers.) This article explains that too many confounding variables have to be factored into the equation of birth order’s effect on personality, and that previous research did not account for these variables. For example, the fact that most CEOs are first-born might be less of a reflection of birth order than of the socio-economic status of the family: the higher the education and income of a couple, the fewer kids they have. “A child from a two-kid family has a 50 percent chance of being a firstborn, whereas a child from a five-kid family has only a 20 percent chance of being a firstborn,” notes Scientific American. The Scientific American article does credit some recent research as rigorous enough to merit consideration, studies that indicate a decrease in IQs from first to last born and a tendency of similarly positioned folks to pair up (youngest marrying youngest, only children buddying up with only children, etc.).
Thus, the evidence seems to be shifting back in favor of our common intuition that our position in our family somehow affects who we become. The details, however, remain vague…The relationship study shows that oldest, middle, youngest and only children differ in some way yet gives no indication as to how. Moreover, although these effects are reasonably sized by the standards of research, they are small enough that it would not make any sense to organize college admissions or dating pools around birth order.
Anyway, if you want to see what your birth order might mean, see this Time article, which is full of statistics that may or may not actually mean anything, but does spell out many of the confounding variables. (Also, I’ve no reason to believe this song has a connection with the novel Gone Girl, but it’s a great little song, so you might as well enjoy it.)