Five years ago cognitive scientist Rafael Núñez found himself in the Upper Yupno Valley, a remote, mountainous region of Papua New Guinea. The area is home to some 5,000 indigenous people, and Núñez and his graduate student, Kensy Cooperrider, were studying their conceptions of time.

Most of you reading this post have a Western understanding of time, in which time has a spatial relationship with our own bodies. The past is behind us, the future ahead. I look forward to Christmas and reach back into my memories. But that particular cognitive framework is not universal. Núñez’s work has shown, for example, that the Aymara people of the Andes think about time in the opposite