Before the white man arrived in Africa and various Pacific island cultures, clothing was pretty much unknown as was sexual attacks (separate those from war conquests). Only after the white man came (read as "missionaries) and insisted on "proper clothing" did sex crimes really start among those populations.
The best way to "protect" children is to expose them to many things at the appropriate times otherwise they end up as "snowflakes" and attempt to eat the forbidden fruit before they're ready to handle it. (Sorry for the mixed metaphor but appropriate methinks).