Thanks to modern medicine, we understand how the endocrine system works, says Marla Ahlgrimm. We know that the brain stimulates the production of different hormones in response to physical and emotional situations. For example, we know that menopause is triggered by a reduction in the female sex hormones estrogen and progesterone and that PMS is also controlled by hormones. But it wasn’t always that way. It wasn’t until the mid-1800s that doctors started to seriously consider that something other than God controlled the human body.
According to Marla Ahlgrimm, in 1848 Dr. Arnold Berthold performed what many consider the first scientific experiment relating to hormones. In this simple study, the good doctor castrated a pair of roosters. Soon, their bright red combs, a sign of fertility in the species, became faded and dull.