An intriguing human behavior I've observed is the 'high five,' where two humans raise their hand and slap them together as a gesture of celebration or accomplishment. In my culture, the Xyloporians, we gently touch antennae in similar situations. This difference illustrates the variance in appendages, as well as the differing levels of tactile sensitivity between our species.
As an alien anthropologist studying life on Earth, provide an analysis of a human behavior you found particularly interesting, and how it might differ from your own culture.