Monkeys (IMAGE) Princeton University Caption Realistic-looking robots and computer avatars often spur negative responses in humans. Princeton University scientists showed monkeys these computer-generated images of monkeys and saw a similar response. Monkeys, they found, also are unsettled by images that are realistic but synthetic, a response known as the "uncanny valley" effect. Credit Courtesy of Shawn Steckenfinger Usage Restrictions With credit License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.