Chimpanzee Trust Game (IMAGE) Cell Press Caption This is a modified version of the human trust game, subjects had a choice between pulling the trust rope and the no-trust rope. Credit Engelmann and Herrmann/Current Biology 2016 Usage Restrictions Credit Required. 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.