"New research indicates that in addition to exchanging goods and services, monkeys adjust exchange rates as supply changes. Ronald Noe, a primate ethnologist, measured the grooming behavior of vervet monkeys in southern and eastern Africa. Among these monkeys, grooming is a hot commodity and is viewed by scientists as a form of “payment” for services. Noe found that when the number of food providers increased, each individual food provider received less grooming."
Tuesday, November 03, 2009
Food for Grooming - Freakonomics Blog - NYTimes.com: