Consequently, exhausted parents accidentally fall asleep on the couch holding their babies when they would have been better off just lying down and napping.
This seems unlikely. 10% of babies share a sleep surface with parents, up from 6.5% in 1993, yet SIDS deaths are down over the same period:
https://www.webmd.com/baby/news/20180212/baby-suffocation-de...
https://www.webmd.com/baby/news/20180212/baby-suffocation-de....
[0] https://safetosleep.nichd.nih.gov/research/science/backsleep...
I'm fairly certain this isn't true. I would expect there to be a lot more flat-headed babies and people around. I don't think I've ever seen one. Not telling you what to do, just pointing out I don't think that part is factual.
And if you think my anecdote is enough, Google will provide you with plenty, e.g., [0].
[0] https://www.nhs.uk/conditions/plagiocephaly-brachycephaly/
Not a study, but I believe this was the article that got her started down the rabbit hole of looking more deeply into this research. We were both surprised to learn that SIDS is significantly more prevalent in western societies that do not have cultures of co-sleeping, and that SIDS primarily occurs when babies are alone. I am struggling to find the article that discusses the breathing component directly, but this touches on it with reference to poor neurological development of human babies and associated weak physiological regulation.
This was the a ha! moment:
“SIDS-deaths are a phenomenon of infant sleep in Western post-industrialized cultures, normally occurring while infants are alone. … Immigrant groups who maintain their ‘traditional’ sleep ecology in ‘Western’ environments typically exhibit substantially lower SIDS rates than the host community.”
This UNICEF page compiled good research on co-sleeping too. [1]
[0] https://academic.oup.com/emph/article/2014/1/146/1846850
[1] https://www.unicef.org.uk/babyfriendly/news-and-research/bab...
I think sleeping with or not with your kid, is a much more complicated question and probably one where your instinct is right. After all, with a baby in the bed you can't help but be aware of its comfort, needs and amount of movement.
If you don't fall into the "bad parent" category you'll be fine.
Regardless, I perceived the emotional bonding with the mother & father to far outweigh anything else and so we shared our bed with our children until they were perhaps 1 year old or so. And even after, they moved into their own small bed just a foot from ours in the same bedroom for another year or so.
I guess that was my "instinct". Although we received a crib as a gift, it just sat in another room, empty.