Why do we nod for "yes" and shake for "no?" Let's ask Darwin.

Why do we nod our heads for yes – and shake them for no?

We humans have been nodding our heads for “yes” and shaking our heads for “no” for a long, long time. It’s a pretty universal expression – so who started it all? Charles Darwin wondered the same thing, and wrote about it in the book “The Expression of the Emotions in Man and Animals” in 1872. In his research, he found the nodding and shaking to be innate behavior to some extent. He noticed babies almost always turned their heads from side to side when refusing food – and would move their heads forward in a nodding gesture when they were hungry.

Darwin also discovered some cultures had their very own version of nodding and shaking. In Bulgaria, the nod and shake were reversed. The Turks said “yes” by shaking their heads from side to side, and “no” by tossing their head back and clucking. We’re still likely to see head-tossing for “no” in parts of Greece and Italy too. The Dyaks of Borneo raised their eyebrows for “yes” and contracted them together for “no.” Eskimoes nodded like us for “yes” – but winked for a “no.”