Note to Rich’s reader: It’s “low-lifes,” not “low-lives.” Just as a baseball hitter who hits a fly ball that’s caught has “flied out,” not “flown out”; just as a couple of those computer hand gizmos on your desk would be “mouses,” not “mice”; just as the preterite of the verb “to joyride” is “joyrided,” not “joyrode”; just as if one sabertooth meets another sabertooth at the water-hole, there are then two “sabertooths” drinking, not two “saberteeth”;… and so on.

Steven Pinker wrote a book about it.