The oldest tablets from Uruk, in Mesopotamia (around 3300–3000 BCE), contain no myths and no poems. The vast majority record rations of grain and beer, livestock and labourers. Writing was invented to manage inventory. Literature, such as the Epic of Gilgamesh, only arrived centuries later.
In Kuşköy, a mountain village in northern Turkey, people talk across valleys by whistling Turkish. A 2015 study showed that whistled Turkish draws on both hemispheres fairly evenly, whereas spoken Turkish relies mostly on the left. The physical form of the signal, it turns out, matters to the brain.
Speech has no gaps between words. In 1996, researchers played 8-month-old babies a continuous stream of made-up syllables for just two minutes. The infants picked out the 'words' by tracking which syllables tend to follow one another. That's probability calculation, done without a calculator or any visible effort.