Alice is a very touch oriented child. She seeks touch as a constant reward and doesn't follow social conventions for personal space, which is a constant uphill battle. School has done a good job of substituting high-fives for hugs and has gone a long way to help educate her peers as well so that the boundaries are firmer.
In a similar vein, Alice and I have our own "secret handshake" for accomplishments. It goes: high-five, knuckles, elbows (see above), shoulders.
It's goofy, but I like it for that very same reason.