I was babysitting my little niece recently and she woke up a couple of hours after going to bed and called for me. So I went up to check on her and she was sitting up half asleep and rubbing her forehead with the palms of her hands. I’ve noticed I do this to when I’m very tired.
Why do humans do this? Do other animals do it?
Rubbing your face or pressing your eyes triggers the ‘oculocardiac reflex’, which lowers the heart rate. This can help you relax when you are tired or stressed.
For me personally, being tired often also comes with a tension headache from trying to push on. Messaging my forehead can help with that. It’s also stimulation that can help keep me awake.
What do you say to it?
I think a more interesting question is how your niece - or anyone - discovers this. It’s similar to the question of why people tend to look up (and often to the right) when trying to think of something or to remember something. Some peculiar behaviors appear to be wired in. Curious.
And on the same tangent, why, when people suddenly are apprised of something they should know, or if they discover a mistake they’ve made, why do people slap their heads? How do people automatically seem to sense that their brains are inside their heads? They don’t slap their sides. Or their arms or their stomachs.
A more mundane reason may be that it’s the result of repressing the urge to rub one’s eyes. From an early age, we all learn the hard way that rubbing them directly or carelessly may push an eyelash or something in there. Also, it may just be a way of momentarily resting one’s neck muscles.