In a comic-strip cartoon, beads of water apparently radiating outward from the head of one of the characters indicate embarrassment. Lines flying horizontally from a character, all in one direction and tailing off with distance, indicate rapid movement in the opposing direction.

Every western child knows this; but were you to show the cartoon to a Tuareg nomad in the Sahara, these ciphers — which are really more a form of hieroglyph than a depiction of any recognisable object — would be meaningless.