A short book whose content can be summarized in a few sentences:
1. You should have more kids than you originally planned.
2. Kids are fun - only infants are hard (and that only lasts a couple of years) - compared with a decades of good times (and more chance for grandkids). Ie that most people over-empathize that period and under-emphasize the long term.
3. Modern American middle class parents are overdoing it in terms of parenting, hence feel over-burdened.
4. Multiple twin studies show that kids will turn out ok no matter what - as long as they have decent genes. Ie parenting can have a short term effect but genes will prevail in the long term.
There is a very long and boring chapter (or multiple ones - hard to tell on a Kindle) in the middle that describes twin studies. I would just skip it - and just take the conclusions as given - however I am not really convinced what this implies for parenting.
I think I have to agree. Our parents did not spend their whole lives chauffeuring kids around and we turned out OK.