Figure 1 A tight-knitter (IMAGE) Dartmouth College Caption Valerie's friendship network: A tight-knitter. Credit Visuals created by Janice McCabe, Dartmouth College. 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.