Yeah well, we have one kid, and we're too old to have another. He's the only grandchild on both sides of the family. He has no cousins, first or second. That's apparently the new normal in many countries. Of course he's going to live a sheltered life! It's easy to tell parents to let their kids roam free, but that advice is to copy the behaviour of parents that had ten kids. I said "had", because on average, two of t…
> I said "had", because on average, two of them will survive to adulthood and procreation. That's natural. That's the way things were for our species for megayears. Where are you getting that stat? For the majority of human history the childhood mortality rate has hovered around 50% not 80%. Back in the second century BC if you had 10 children you expected half of them to reach adulthood. In addition I can't find spe…
Basic population dynamics. For a population to remain steady, a breeding pair can only have on average two surviving children that procreate themselves.
If you want to get into the weeds, there's obviously some "fudge factors" that bring this a little bit up above two.
1. Not every kid that survives to adulthood will go on to procreate themselves, so the remainder need slightly more than two to make up the slack.
2. During periods of population growth, the average survivorship has to be higher.
3. The percentage surviving depends on how many were born per family to begin with. I didn't state a percentage, I said two. Okay, fine 2.4 or whatever, but not a fraction, that "depends" on too many variables.
> For the majority of human history the childhood mortality rate has hovered around 50% not 80%.
RECORDED history, which is a short blip in our evolutionary history as a species. I said megayears, a.k.a.: millions of years, for most of which we have scant evidence. Extrapolating from our wild animal cousins and just observing how these "uncontacted" tribes live, it's pretty obvious that for 99% of the time we could be called human, we had five+ kids per couple, and ten+ wasn't uncommon... of which two-point-something survived.
That's just the way it is, for essentially all species. It has to be, otherwise populations would explode in numbers until it's standing room only for the entire surface planet.
PS: Next time you watch some BBC documentary about some species giving birth to hundreds of offspring, well... now you know. They didn't make it. Certainly, statistically, most of them must not have, because if they could and did, then that species would have their population numbers grow astronomically fast!
PPS: You hand-waved away a 50% loss rate as if it's a detail. That in no way undermines my argument that if you have an only child, or even two or three, that losing half of them is not considered acceptable parenting in this day and age. There is absolutely no way anyone I know would trade half of their children so that they can have a wild, carefree, and unsupervised childhood like "nature intended"!