A cat rubs against humans not only to be affectionate but also to mark out its territory with scent glands around its face. The tail area and paws also carry the cat’s scent.
When cats rub against us, they deposit their scents on us. Each cat has a unique scent. When a cat rubs his scent on us, he’s reaffirming that we’re part of his exclusive club. His scent, blended with ours and the scents of other household members, is like an identification mark.