This was long suspected. I've seen countless examples of this in real life. But it was never "proven" like this. This was really interesting to me: "But surpr

This was long suspected. I've seen countless examples of this in real life. But it was never "proven" like this. This was really interesting to me: "But surprisingly, when we removed the adrenal gland from the mice so that they couldn't produce cortisol-like hormones, their hair still turned gray under stress." It's also permanent.