Pulitzer-winning New York Times critic Jefferson collects her meditations on what may be the oddest show-biz figure of all time. “Freaks” is the title of her first essay, and she notes Jackson’s attraction to Barnum as well as the strangely apt imagery of his best-known video, “Thriller.” Born in 1958 to a bullying father and a mother who was a Jehovah’s Witness convert, the youngest member of the Jackson Five quickly became its VIP. Child stars are never “normal,” and Jefferson glances at Buster Keaton, Jackie Coogan, Sammy Davis Jr. and, of course, Shirley Temple, the only one of them even more famous than Jackson, unless you count Elizabeth Taylor, Jackson’s “best friend,” who supplanted Diana Ross as his apparent role model. Jackson, Jefferson believes, is a “sexual impersonator,” imitating, at times, a gay man, a white woman, a “gangsta” and a “pop Count Dracula.” His bizarre looks and behavior drew literally thousands of cameras to his 2005 trial for child molestation. Jefferson concludes that Jackson may be a “monstrous child,” but that he is, to a degree, a mirror of us all. Her slim, smart volume of cultural analysis may remind readers of Susan Sontag’s early, brilliant essays on pop culture.