Medical researchers have found that qualities like faith, hope, and forgiveness, and the use of social support and prayer seem to have a noticeable effect on health and healing. A person's most deeply held beliefs strongly influence his or her health. Some researchers believe that faith increases the body's resistance to stress. In a 1988 clinical study of women undergoing breast biopsies, the women with the lowest stress hormone levels were those who used their faith and prayer to cope with stress.