Members of the Amazonian Akabe people commonly take an early-morning drink of a tea made from the leaves of a forest plant  Although they greatly enjoy this drink, at dawn they drink it only in small amounts
Anthropologists hypothesize that since this tea is extraordinarily high in caffeine, the explanation for the Akabe' s not drinking more of it at dawn is that high caffeine intake would destroy the surefootedness that their daily tasks require
The Akabe also drink the tea in the evening, after their day's work is done.