How Cooperative Thrives or Fails (IMAGE) University of Pennsylvania Caption Despite their reputation, spotted hyenas are often cooperative animals, dwelling in large groups and assisting one another during hunts. Penn biologist Erol Akçay modeled a theoretical social group to show how cooperation can arise or collapse. Credit Amiyaal Ilany Usage Restrictions In context of reporting 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.