Testing the Drunken Monkey Hypothesis in Panama

Could alcoholism in humans be an evolutionary hangover? Robert Dudley, professor of Integrative Biology at the University of California, Berkeley believes so. His “Drunken Monkey Hypothesis” suggests that fruit-eating primates —such as BCI’s spider monkeys—may be drawn to naturally occurring ethanol in the fruits they consume. Frugivorous primates have been eating fermented fruit for 40 million years. The health benefits of low-level alcohol consumption are consistent with an ancient and potentially adaptive exposure to this common, psychoactive substance.

Christina Campbell, associate professor of Anthropology at California State University Northridge, who has studied behavior, ecology and reproduction of spider monkeys, Ateles groffroyi, since 1996, is back on BCI with graduate student, Victoria Weaver, to test Dudley’s hypothesis. They will measure the ethanol concentration in the sugary fruits of Spondias mombin, a mango relative extremely important in the monkeys’ diet.

Christina and Victoria will be running through the forest chasing spider monkeys to collect fallen fruits and/or urine samples (which will be tested for an ethanol metabolite) until September 2014.