When a cat rubs your leg, what else may it be doing?

Answer: Leaving familiar scent signals

Leaving familiar scent signals ✓ — Correct! Rubbing is partly social, but it is also chemical communication. Cats have scent glands around the cheeks, chin, head, body, and tail base. By rubbing you, the cat can mix familiar scents and mark you as part of its safe social world.

Testing if you are furniture — Wrong. Your leg may be furniture-shaped from a cat's height, but that is not the main mechanism. The better explanation is pheromone communication: leaving a familiar scent signal on an important person or pathway.

Polishing your ankles — Wrong. If cats polished ankles, every cat owner would have mirror-bright shins. The real action is less visible: scent molecules and pheromone information being deposited during contact.