In quite a few languages, the word for ‘twenty’ is derived from a word meaning ‘person’ or ‘body’. The logic runs like this: 5 is ‘a hand’, 10 is ‘two hands’, 15 is ‘both hands and a foot’, and 20 is ‘all hands and feet’ – in other words, all the digits of our bodies.

Also in quite a few languages, the word used to designate both the language itself and its speakers literally means  ‘person’ or ‘people’ or ‘real people’. The Yami of Taiwan, for instance, call themselves Tao or ‘people’, and their language ciriciring no tao, ‘speech of people’.