Monkeys Pay for Prurient Pictures

Join Our Community of Science Lovers!


On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


For a monkey, not all images are created equal. A new report reveals that the animals value some pictures more than others and are willing to pay for the privilege of viewing the important ones. The results indicate that monkeys, like people, value information based on its social context.

Robert Deaner of Duke University Medical Center and his colleagues studied male rhesus macaques that received juice rewards while looking at a variety of images of other macaques on a computer screen. The pictures included a neutral target, male monkeys that differed in social standing and the hindquarters of a female monkey, which reveal her sexual receptiveness. By systematically varying the amount of juice offered to the monkeys while changing the pictures they were seeing, the scientists determined how much the animals were willing to give up, or pay, in order to glimpse specific images. The team discovered that monkeys would give up a significant reward if it meant viewing high-ranking individuals or female behinds. But when given the chance to glance at images of low-ranking males, the subjects held out for additional juice.

The findings may help scientists understand the neural wiring that underlies social cognition. "At the moment, it's only a tantalizing possibility, but we believe that similar processes are at work in these monkeys and in people," says study co-author Michael Platt, also at Duke. "After all, the same kinds of social conditions have been important in primate evolution for both nonhuman primates and humans. So, in further experiments, we also want to try to establish in the same way how people attribute value to acquiring visual information about other individuals." The findings will appear in the March issue of Current Biology.

It’s Time to Stand Up for Science

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.

I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.

If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.

In return, you get essential news, captivating podcasts, brilliant infographics, can't-miss newsletters, must-watch videos, challenging games, and the science world's best writing and reporting. You can even gift someone a subscription.

There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.

Thank you,

David M. Ewalt, Editor in Chief, Scientific American

Subscribe