spontaneous neanderthalism Share definition Flag The process by which an ofspring from a nice family becomes a jerk. Joel's mom is so nice, but he's such a bigot. Must be a case of spontaneous neanderthalism. spontaneous neanderthalism by JavaJaneOhio August 12, 2010 0 0 Get merch Get the spontaneous neanderthalism mug. Buy Now — $32.95 See more merch