[leoedin]

Anecdotally, it was my more risk taking and carefree friends that had kids first. I can see why - with just a little effort it's very easy not to have kids in the modern world, and the cost-benefit analysis for children is pretty bad.

What that means for the future of humanity, I don't know.

[0xDEAFBEAD]

It's not necessarily that simple though. Maybe if you have an unplanned child early, you realize that thing about the cost-benefit analysis being bad, stop having kids, and reproduce at below replacement.

Here is one paper I found on correlates of reproductive success in the US, from 2005 though: https://d1wqtxts1xzle7.cloudfront.net/48563240/Sex_Status_an...