Mason Lab Rat (IMAGE) University of Chicago Medical Center Caption A rat is less likely to help a trapped companion if it is with other rats that aren't helping, according to new research from the University of Chicago that showed the social psychological theory of the "bystander effect" in humans is present in these long-tailed rodents. Credit Mason Lab Usage Restrictions None 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.