Everyone knows that some babies, at least in the modern Western world, have times during the day where they’re fussy. They’ve been fed, their diaper is clean (and they don’t want to be taken to the potty, if they’re doing EC), and they’re either crying or would be crying if someone weren’t soothing them. In some babies, the problem seems to be caused by gas, reflux, or other digestive issues. Most if not all of us are eating a diet these days that’s well outside ancestral parameters. Dairy and wheat especially seem to cause problems for some babies.
The Kung! San supposedly don’t report evening fussiness in their babies, but it’s not clear to me it’s because their babies don’t get fussy–maybe they’re just better at soothing them. Lydia has never been inconsolable, but has occasionally required fairly substantial intervention (breastfeeding while swaddled while I’m walking and shushing her). My (very likely naive, largely informed by a handful of books) understanding of hunter gatherer populations is that they’re emotional systems are less inclined to fight against reality than our modern-day ones, so it’s that they take the extra soothing effort in stride. Plus, there are a bunch of people around to help, and they would have had experience caring for babies since they were pretty young themselves, and are likely to be better at it.
My current leading theory for Lydia’s fussiness is one that’s mentioned in a few books, including Healthy Sleep Habits Happy Child: she gets overly tired. She does have gas pretty frequently, but the timing just doesn’t seem to fit. I wouldn’t expect any sort of digestive problem to cause fussiness for a few hours at a time, often in the evening. From what I can tell, Lydia is happiest just when she gets up, then she gradually gets more inclined to be fussy until she sleeps again, at which point the cycle repeats.
Lydia has never been fussy right when she woke up. And I’m pretty sure she’s never been all that calm after having been awake for several hours. Fussiness decreases when I’m good at soothing her, but it pretty much always ends with her falling asleep.
I initially found myself blaming artificial lights, but I’m actually not sure how much that matters. My understanding is that babies don’t produce much melatonin in the first few months, and fussiness decreases around the time they start producing more. Maybe the problem is that we try to get babies to sleep for longer periods during the night in the first place. My experience, common sense, and baby books seem to agree that, while being too tired can interfere with sleep, babies also can’t sleep more than a certain amount throughout the day. The usual situation is that parents don’t like it when babies sleep “too much” during the day and not enough at night.
I wonder whether more of a true polyphasic schedule would eliminate baby fussiness. Maybe we could eliminate long wakeful periods by eliminating long sleep periods.
I have pretty low confidence in this prediction, but at least it’s easily testable.