@Starlight"CulturalAssumptions"McKenzie
"This is riddled with assumptions. Is it indeed possible for a baby to become overtired? What does this mean exactly? Why would you assume babies might not get as much sleep as they need?"
It's not exactly riddled with assumptions, is it? It makes one assumption, which is that babies need a certain amount of sleep and that it is possible for them to get too little.
It doesn't even assume that there is a particular range of hours within which any individual baby's sleep tally must fall to be sufficient.
You're right that the word overtired is not clearly defined, so I will clarify that what I mean is a baby who has not had as much sleep as they need.
Now the thing to tackle is that one assumption and turn it into a question: is it possible for a baby to get less sleep then he or she needs?
Can any of the child development experts weight in here?
I think unless I am proven wrong that I will make the assumption that it must be possible for a baby to get insufficient sleep as I think it is not contentious to say that it is possible for adults to get insufficient sleep and I am prepared to assume that since babies are also human that the same might be true for them.
Could it be that people are born always getting the right amount of sleep and only develop the ability to sleep less than necessary as they grow older? Is it like breastfeeding that a baby somehow knows how to regulate their own sleep so that they always get exactly what they need?
Personally I don't believe that the above is the case, but that is entirely based on personal experience and anecdote and I'm open to having my mind changed on that.
Perhaps where you stand on that central assumption will inform how you deal with your LO when it comes to sleeping.
For example, quite recently my DD (8 months) began waking a lot during the night. Someone of the "sufficient sleep" persuasion might have just assumed that she needed less sleep and just got up with her when she awoke. I dealt with it as a problem that needed to be fixed and tried to find out what I needed to do to make her start sleeping until morning again.
Eventually it occurred to me that perhaps she was being disturbed by us in the night, so DH and I moved to another room to see would it help. It did. Instantly she started sleeping through again. I had been planning to share a room with her until she was at least a year old. This was my compromise with DH who really didn't want to do co-sleeping. I missed her terribly when we first started sleeping in another room , but I thought it was important for her to get a good night's sleep. Sharing a room wasn't working for her anymore, so I fixed it.
Another parent with a different approach might have done something entirely different. I could say that it would have been cruel to have stayed in the room with her when it was obviously disturbing her. But perhaps a different me would think it more important that when she did inevitably wake (which she still does occasionally) that I was right there beside her rather than it taking me a few minutes to get to her (I'm not far away, I just lose my glasses most nights).