" The signals confused Mma Ramotswe; she knew the Indian habit of moving the head from side to side meant the opposite of what it meant elsewhere and signified approval rather than disagreement, but she was not sure what a combination of movements meant. Perhaps there was something wrong with Mr. Sengupta; perhaps his head was loose. "

― Alexander McCall Smith , The Handsome Man's Deluxe Café (No. 1 Ladies' Detective Agency #15)