For a long time, I've had on my wall a sketch of five little figures scurrying about, oddly perky despite the fact that two of them have nails driven through their heads. The drawing's intrinsic weirdness is enhanced by its provenance: The artist was an inmate of a Wisconsin mental asylum, circa 1905, or so I was told at the antiques shop in the small Iowa town where I bought it.

This was years before "naive art" was in vogue, years before you could attend an "outsider art fair" to observe the spectacle of dealers vouching for the alarming credentials of the artists they represent—the brutal murders for which one such artist had been imprisoned, the desperate severity of another's mental health problems. It's a species of comedy that the recent film Junebug—which features an outsider artist from North Carolina—cleverly captures by having a dealer in such art casually mention, during an auction, those three magic words: incarceration and autism diagnosis. According to Lyle Rexer's How To Look at Outsider Art, the term "outsider art" was coined as recently as 1972 by art historian Roger Cardinal and is currently used as a sort of catchall term to include folk art as well as work made by people who may be eccentric, visionary, insane, self-taught, and who, in any case, exist far beyond the fringes of what we might call "the art world."