From the 16th to the early 20th century almost all autopsies were of people from the lower social-economic class (i e…poor people). There were a lot of reasons and laws that caused this situation to occur. Stresses related to being a part of this class of people affects the body and hormones in the body. One of the things that happens is that the thymus gland shrinks. Around the early 20th century the disease know as SIDS (sudden infant death syndrome) was being investigated. Many of these children that were being autopsied were from the more privileged class of people and those autopsies found ‘normal’ size thymus glands. The problem was that doctors thought that the smaller thymus was normal size due to the autopsies that had been preformed in the past and that SIDS must be due to an abnormally large thymus. Wealthier citizens were told by their doctors to irradiate the thymus to make it smaller to prevent SIDS. This eventually caused large number of cases of thyroid cancer.

(The Great Courses – Being Human: Life Lessons from the Frontiers of Science)