No HN discussion of voluntary finger amputation would be complete without mentioning that it was central to a superb science fiction short story: Richard McKenn

No HN discussion of voluntary finger amputation would be complete without mentioning that it was central to a superb science fiction short story: Richard McKenna’s "Mine Own Ways", which appeared in the 1961 "Year's Best SF" as well as in anthologies published after the author's 1964 death. To oversimplify, an interstellar anthropologist on a primitive planet discovers that the amputation ritual is crucial for the evolution of the hominids he is studying into full-fledged humanoids-- by needing to get his own finger chopped off. If anyone finds themself thinking about this particular gruesome subject for any longer than the time it takes to scroll these comments, then McKenna's story is worth a read. The Internet Archive has a crummy OCR version.