The Thinning Middle (IMAGE) Santa Fe Institute Caption One prediction from the researchers' model is a bi-modal distribution for group 1, group 2, and in-betweeners. Credit (Yang et al, PLOS One) Usage Restrictions Attribution 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.