Experiment (image) Uppsala University Share Print E-Mail Caption This is a child and a mother doing a test. The persons are not part of the study. Credit Terje Falck Ytter Usage Restrictions When describing this study Share Print E-Mail 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.