And here I just thought it was a plot to keep everyone too tired to do anything but sleep when they could, ovulation makes it besides the point...
That was also my assumption. That, and making you question why you did this in the first place.
Is there any strong evidence that having a sibling makes a human any less likely to survive to reproductive age? I believe (without evidence) that we could just as easily hypothesize the opposite: once siblings are mature enough, they can help and defend each other.
Further, doesn't this go against the idea that siblings are altruistic towards each other because those who are will be more likely to continue their (family's) genes? (Swap order of cause and effect there for more correct evolutionary thinking, of course.)
Have evolutionists worked out which is more fundamental, sibling rivalry or sibling altruism?
In any case (but particularly without being clear on the answers to the above), like many evolutionary arguments this seems like a little bit of a just-so story.
You mean that women delay ovulation when feeding babies at night to avoid having a second baby to feed too soon?
These kinds of theories that suggest the causation works one way and not the other are very annoying to me.
Babies - the cutest of the cockblockers.
Not sure I'm buying it. Women have been successfully birthing and raising twins for all of recorded history.
Birthing twins is irrelevant to a discussion about decreased ovulation from breastfeeding.
I think this is appropriate:
Why do we need a complex theory for something that seems very clear and obvious? Occam's Razor suggests babies wake up in the middle of the night and scream for food because they are hungry and screaming brings food, no?
Relevant to the "babies can't handle competition" angle though.
The article is more about "babies don't want competition" than "can't handle."
If we're looking at this evolutionarily, then changes in human civilization in the last 10,000 years mean nothing.
A baby screaming in the middle of the night is a HUGE problem if it draws predators. There has to be some advantage to it, or it's genetically linked to something that has an advantage to it, or else all the screaming babies would have been killed long before any country we now know the name to was created.
This doesn't mean competition for scarce resources is the explanation (or the only one), but it certainly seems like it should be on the short list for consideration.
If we're looking at this evolutionarily, then it's unlikely a baby would be left to sleep alone prior to 10,000 years ago (assuming its parents cared whether it lived or died). Leaving a baby to sleep in a crib—especially in a different room from its parents—is a pretty newfangled idea.
Actually a lot can happen in 10,000 years, put a toy poodle next to a great dane and see.
True, but babies still cry in the middle of the night even when they're lying right next to their parents.
Edited to add: In fact, that's considered one of the selling points of putting a baby alone in a room to sleep: it's said that they're more likely to sleep through the night sooner. It has been argued that the reason is because they've learned through experience that mom & dad don't hear them to come help as quickly. Another explanation is that they're less likely to be woken by other people's noises and movements in the night.
You couldn't pay me enough to go through those early years of exhaustion again!
Presumably the parents with spears and fire...
The 1% of their time, hmm?
I imagine that a hunter-gatherer society back then would operate similar to one now and pool village resources. It's not like they had Flintstones-style private bungalows they went home to.
It wasn't even the norm in "the West" until the industrial revolution made shiftwork a thing.