When was the last time you helped another person? Maybe you helped an elderly person up some stairs or made a donation to a charity. Do you remember how this act of kindness made you feel? Research suggests that helping others can make us feel better and can even improve our physical health. This phenomenon is known as the Mother Teresa Effect. The term originated from a study conducted at Harvard University. Researchers showed 132 students a film about the work of Mother Teresa, a Catholic nun who helped the poor and sick of 20th-century Calcutta, India. When the film finished, the researchers measured the students' level of immunoglobulin A, which is one of the body's first defenses against viruses. Amazingly, their levels of immunoglobulin A had increased significantly after simply watching Mother Teresa doing charity work. So, if watching someone performing acts of charity has such a strong effect on people, what are the effects of actually doing charity work yourself? A study of 3,000 volunteers conducted by Allan Luks and Penny Payne found a variety of psychological and physical benefits. The volunteers experienced a feeling of happiness and energy followed by a helper's high of peace and calm. Physically, the volunteers found that some of their health problems, such as stress, chronic pain, and insomnia, were reduced after volunteering.