Martine Stead, University of Stirling (IMAGE) University of Stirling Caption Lead author Martine Stead, Deputy Director of the Institute of Social Marketing. Credit University of Stirling 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.