I received a note from the author of the study, Luisa Livingstone, who provided more information and corrections- not the least of which is that she has not yet been awarded a PhD. This reflects her additional information.
I’ve written about my pain threshold before. Where I’ve obtained (now, there’s a verb choice) 3rd degree burns all over my arm and kept on working. Or, broken my leg and kept on going. Well, it turns out that we can train our genes to provide this benefit.