Does anyone remember the early scenes in Malcolm X, where Denzel Washington in a zoot suit is straightening his hair with lye, and the white guys shut off the water so he has to rinse off his head in the toilet before his scalp gets burned? A lot of people have burned a lot of hair and skin trying to straighten hair, and the idea of "good" straight or loosely-curling hair versus "bad" tightly-curling hair is old.

I always thought the UK "nappy" was short for "napkin" (which we, in the U.S., would use in our laps at meals rather than on a baby, but which is not unlike a diaper). And "nap" is OK when applied to things other than people, such as carpet (we have short-nap carpet in the den--the kind with very snug, short loops instead of soft pile).

"Boogerboo" or "buggerboo" or "bugaboo" or whatever is the same as the bogeyman/boogieman in the United States (at least in the South). Lots of word variants on the same idea. There's an old song called "Boogerboo"; the version I have is on the Red Clay Ramblers and Fiddlin' Al McCanless. I've never heard "jigaboo" substituted, but then I live in Texas and there is no doubt here as to the meaning if that particular word, nor would I find the abbreviation "jig" to be amusing.