NPR's Michel Martin speaks with Pulitzer Prize-winning biographer Ron Chernow about his new book, "Mark Twain," in which he illuminates the complex life of the writer.

Pulitzer Prize-winning author Ron Chernow is known for writing massive biographies of the country’s most enduring figures, ...

Eighty percent of women masturbate. Ninety-five percent of men masturbate. And the rest lie.” This Masturbation Awareness ...