In this picture taken on Thursday, June 19, 2014, an unidentified Iranian woman practices in an outdoor session of a Laughter Yoga class in the Darakeh mountainous area north of Tehran, Iran. The course in Tehran helps people from various age groups and social backgrounds to have fun and take a break from stressful daily lives. Laughter Yoga was started in India in 1995 by medical doctor Madan Kataria, in response to a body of scientific research which shows that laughter is extremely good for physical, emotional and mental wellbeing. (AP Photo/Vahid Salemi)