Outsider artists have been known to achieve their alien status through insanity, but more frequently the artist is outside the mainstream population by means of his race, physical or personality differences, or national or religious affiliations. Some have been shocked by war experiences into isolated consciousness or inspired by religious experience. It is often an enigmatic eccentricity that gives them the courage to pursue their convictions and individuality to create what Jean Dubuffet first labeled art brut. In any case, the artist’s soul, available mediums, philosophy, and background are evidenced in his final product, which reflects a lifetime of experiences. — Roger Manley, Signs and Wonders: Outsider Art Inside North Carolina (Raleigh: North Carolina Museum of Art, 1987), 8.
In the United States, outsider art has been understood more broadly than in Europe and has often been popularly conflated with folk art, ethnic art, and many other gestures produced by various outsider groups and individuals. — Michael D. Hall and Eugene W. Metcalf, Jr., eds., The Artist Outsider: Creativity and the Boundaries of Culture (Washington and London: Smithsonian Institution Press, 1994), xii.