Sal knows body parts - can point to his nose, mouth, teeth, ears, belly, knees, hair (?), feet, toes, hands and such. And apparently, he knows something about how they all should be put together - roughly at least.

He was at a counter and since it is getting close to Halloween time, there were decorations out. These decorations included a decapitated head and a little motorized moving severed hand. The first time the hand moved, he glanced at it. But when it started to move again, he didn’t like it. Then saw the head. He was pretty completely disturbed by then.

In research circles, they look for things that get extra attention from babies, to measure interest. And how far out from the norm things are. If things are normal, the babies don’t pay too much extra attention, since there are so many other things to study in the world. I’d guess that younger children, without as complete a mental model of how the world should be, wouldn’t be as startled by the hand and head. They’d just be different objects in the world, without any meaning behind them. As they interact with people more, seeing more faces, giving more high fives, they begin to get a deeper understanding behind what a head and hand should be like.

So we’ll count this up as him knowing body parts should be attached somehow to make a “whole”. And/or he’s not a big fan of the horror genre…