Random choice among the Kantu, swidden agriculturalists of Kalimantan
An excellent post by Michael Schulson at Aeon magazine entitled "How to choose? When your reasons are worse than useless, sometimes the most rational choice is a random stab in the dark," showing, among other things, how rationality and expectations of rationality can clash.
"In the 1970s, a young American anthropologist named Michael Dove set out for Indonesia, intending to solve an ethnographic mystery. Then a graduate student at Stanford, Dove had been reading about the Kantu’, a group of subsistence farmers who live in the tropical forests of Borneo. The Kantu’ practise the kind of shifting agriculture known to anthropologists as swidden farming, and to everyone else as slash-and-burn. Swidden farmers usually grow crops in nutrient-poor soil. They use fire to clear their fields, which they abandon at the end of each growing season.Like other swidden farmers, the Kantu’ would establish new farming sites ever year in which to grow rice and other crops. Unlike most other swidden farmers, the Kantu’ choose where to place these fields through a ritualised form of birdwatching. They believe that certain species of bird – the Scarlet-rumped Trogon, the Rufous Piculet, and five others – are the sons-in-law of God. The appearances of these birds guide the affairs of human beings. So, in order to select a site for cultivation, a Kantu’ farmer would walk through the forest until he spotted the right combination of omen birds. And there he would clear a field and plant his crops. Dove figured that the birds must be serving as some kind of ecological indicator…