On Saturday, Adrian and I were lounging around the house when we got into a mini-argument fueled by classic sibling rivalry and vanity.
“Let’s ask mom who she think is her best looking child.” I suggested.
“She’s going to say me, you know she is,” Adrian retorted.
“No. She won’t even answer the question. She’ll stay out of this one,” I reasoned.
We interrupted her Christmas decorating so that she could serve as a referee.
“Mom, who is your best looking child?” I asked.
Without taking a moment to think it over, she responded, “Adrian.”
Adrian smirked.
“Hey!” I exclaimed feeling a bit betrayed that she chose the baby of the family over the future PhD.
I turned to my supposedly handsome little brother, “whatever, you may be the best looking, but you’re also the youngest and research shows that if you’re born later in the family, you’ll have a lower IQ.”
Adrian looked a me confused and annoyed that I had used my nerdiness to come out on top.
I guess doing the assigned reading for class that week had paid off. While reading the education chapter of David Halpern’s Social Capital, I came across the following passage
Partly this result [educational attainment is higher for children from two parent households] is expained by the fact that having two parents around, as opposed to one, implies more child-parent contact. Further support for this simple structural interpretation lies in the finding that having more brothers and sisters, or being later born in a family, is associated with marginally lower IQ and worse educational achievement (Zajonc & Markus, 1975 [more on their research]). Essentially, having more kids in the household ‘dilutes’ or reduces the time that later-born children are able to spend with their parents (pp. 145-146).
I had never considered the link between family size or birth order and achievement, so the passage stuck out.
Needless to say, I won the argument with a little science, even if the link between intelligence and birth order has been disputed in longitudinal studies.
Older siblings, you can thank me now. Your younger brother/sister may be better looking, thinner, funnier, more athletic and what not, but you can say “psychologists have shown that I’m smarter ’cause I’m the first (or second) born!”









