Early research supporting the Social Readjustment Rating Scale (SRRS) includes a study on U.S. and Norwegian Navy personnel, which found a positive correlation between their Life Change Unit (LCU) scores before a six-month voyage and their subsequent illness symptoms during it (Rahe, 1974). Another study showed that individuals report more physical symptoms like backaches and upset stomachs on days with unusually high self-reported LCU values, such as the day of a family wedding (Holmes & Holmes, 1970).