Hard to argue with the stats and reasoning in this article.
For the first ~99.95% of that time range, infant mortality was very high, and then it sort of dropped like a rock. A lot of the change is attributable to breaking with tradition.
I don't mention this by way of suggesting that everything traditional is dangerous, so much as to say that this is one of those spots where we should regard a simple appeal to tradition as being particularly unconvincing.
Is it? I thought it was due to modern medicine. Do you have a reference?
In the spirit of modern medicine, I'd suggest that that article was chock full of stats that should get much higher billing than a line of reasoning that's of a kind with one of the main ones that people use to promote acupuncture.
We tend to put a greater value on human life than that, even (or especially), traditionally.
Nobody is suggesting getting rid of indoor plumbing, water treatment, antibiotics, vaccines, hospitals, or large-scale agriculture.
There is real risk here, and while we can deal with it in a smarter manner (the New Zealand example with the Moses baskets and identifying high risk babies for example), in bed sleeping significantly increases the mortality risk, even for low risk groups. The info graphic indicates the risk of in bed sleeping from 1/46000 to 1/16000. At 4M live births per year, that’s a difference of roughly 89 children dying versus 250 children dying. What’s more, those numbers are cited for SIDS, it’s not clear where a death where the cause is known (like rolling over and suffocating the baby) would count as in these studies.
In short, I’m unconvinced we should be encouraging in bed cosleeping
We did not cosleep with our child. But in the process of reviewing many sleep guidelines we reviewed the literature and found it's more complicated than it seems. The NPR article doesn't summarize the complexity as well as it could.
The problem is that studies of risk of cosleeping generally do not control for confounding variables very well at all, and when you do control for these confounds, the risk of cosleeping disappear.
For example, in the US many cosleeping parents tend to be minority, immigrant, lower SES, etc. which is associated with other risk factors. When you control for those trends, cosleeping isn't associated with increased risk.
This has lead to many sleep scientists to conclude that cosleeping research has largely been sociodemographically (e.g., ethnically) biased in design and analysis. There's a big rift between sleep scientists and pediatrics in this regard.
The NPR piece proceeds along the lines of "humans have been doing this for 200000 years so it must be fine" but it's more like "people who can afford separate beds for their children tend to have a lot of money, globally speaking, and that's associated with decreased risk of infant death for a multitude of reasons having nothing to do with cosleeping."
Welcome to sociology, the home of bad research practices.