How is it that a sleeping child being held in your arms can sense when you are standing and when you are sitting? There is something very complex going on there. They must be sensing the movements in between the positions and their brains keep track of the current state. So, they sense the “sitting-down-motion” and their brain triggers the “oh-no-the-big-person-holding-me-is-sitting-now!” alarm that prompts them to begin wailing.

It’s interesting how they do it, but it’s also interesting why they do it. My theory starts with the fact that human babies are essentially defenseless. In order to ensure their survival, they need some way to get big people to protect them. There are many mechanisms at work here (“the parental instinct,” “love,” etc.). In this particular case I think there are two forces at work. One, the sitting position is inherently more vulnerable than standing. So, when you are sitting, the baby may feel less secure than when you are standing. And two, crying is the child’s way of training parents to do what the child wants. It’s very Pavlovian.

The motivations and mechanisms are fascinating. And yet, at 2am, still annoying.