Male humans don't do a lot of mutual grooming.
Teen aged females do. Or at least they did in my day.

"I have, on the other hand, had plenty of experience whooping, screaming and waving my arms about when excited."

Sounds like any group of men when their team scores.

Are chimps dim reflections of ourselves? From our point of view maybe. But to them, we must look like weak slow, inhibited versions of them selves.