SPIT Lab Research (IMAGE) Iowa State University Caption Iowa State's SPIT Lab is at the forefront of biobehavioral research, using hair samples to study how hormones and environmental factors influence puberty. Credit Iowa State University News Service 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.