https://twitter.com/paulg/status/1364302749307928580?s=21&t=...
Not to outsource my thinking, but it’s not my idea. I only noticed the effect once he pointed it out, and then it seemed obvious.
The refutation to this is three children. If it was true that someone’s character wasn’t inborn, then we should see consistent effects on a middle child on average. But middle children seem equally random. My wife’s sister is an introvert and her other sister an extrovert, and it’s hard to square that with upbringing.
I predict in the future embryo selection will become a new cultural battleground. We’re having a daughter nine months after June, and we know this because it’s now possible to select which gender you want during IVF. It seems a matter of time till the introversion genes are similarly selected for.
If they go to the same school one of them had to go in ‘cold’ while the other went somewhere familiar they had heard the older sibling talk about and had probably visited before, where the teachers already knew the elder sibling and knew some of their friends.
It’s a very different experience and situation to live in.