Utilizing data collected on 20,000 people enrolled in the 1958 British Birth Cohort study, Dong Pang, from University of Aberdeen (Scotland), and colleagues found that those who experienced "severe behavior disturbances" between the ages of 11 and 16 years were about twice as likely to have chronic widespread pain by the time they were 45 years of age, as compared to those without behavioral problems as children. The researchers failed to find a basis in social class, early reporting of symptoms, or adult psychological distress. Rather, they posit that a dysfunction in the interaction between the nervous system and hormones that occurs in childhood may have long-term consequences for adult health. While previous studies have found a link between physical trauma and chronic pain in adulthood, the team speculates that stress due to past trauma may impact the neuroendocrine system (specifically, the hypothalamic-pituitary-adrenal axis), and as a result lead to behavioral problems in childhood and chronic widespread pain in adulthood.