"Ten weird signs that you are highly intelligent, according to science" - First born children are usually the cleverest, with measurable differences in IQ as early as age one – and it’s thanks to their parents.
It's a tough position. The first is the one who breaks all the new ground - has all the arguments with parents and makes it easier for the ones who come later. :)
I'm an only child; but in talking to my dad when I was a little older, I got the impression they would have welcomed more.
Possibly heading off my thoughts that I had missed having a sibling; my dad said that if he had $20 to spend on his kids and I had a sibling, I would get $10.---while as it was, I got the whole $20.
(It wasn't about money---dad was an accountant and money was his second language.)
I'd have loved to be the seventh son of a seventh son and have all that mystical ability but my ancestors had absolutely no stamina. I'm fourth of five kids. (And my little brother is still a pain in the butt.)