I don’t know the evolutionary function of it, but trauma does affect your health and longevity, as well as things like weight and immune system. There’s a lot out there on this if you Google it, but here is the story that I linked in the OP.

Parents' emotional trauma may change their children's biology. Studies in mice show how

I’m giggling a bit about the Snoopy parents part, so thanks for the smile and let me know your thoughts on any of this you wish to discuss further.