This is an interesting question. I have noticed that so many of the kids in the exceptionally gifted class here are only children. I've always wondered why--are they more easily identified because parents can focus more on them? Is it an argument for nurture v. nature? Was it choice or circumstance? Are they too much of a handful to have more?
There was recently an article about the firstborn being the smartest, though it doesn't correlate in my family based on the IQ tests. For me personally, I didn't decide to have more kids for my son to enjoy siblings. In fact, I remember him specifically being angry about a new baby. "One baby, Mama. No more babies!" I wanted more because of what it did for me. I felt like the grinch whose heart multiplied a hundred times in one day when my son was born. After that, I thought there was room for more and more love. Hard to explain. I guess I'm just glad I got a pretty late start or we'd have a dozen instead of 4.
For us, we really didn't have a clue about them being gifted until my oldest was in kindergarten. I must have thought all kids knew every dinosaur's scientific name and every fighter jet's specifications at age 2 or 3. The kindergarten teacher was the one who suggested testing him. After that, I read quite a bit and was pretty proactive about having them identified.
This summer when one or more kids were away at camp it became apparent that having just one or two is not necessarily easier for parents that 4. I had to be much more involved once there were no playmates. However, there was definitely less fighting.
