Photo by the Art Archive/Archaeological Museum, Amman, Jordan/Dagli Orti.

With its unfocused eyes and fang-like teeth, this Neolithic plaster mask from Jericho resembles a drowsy monster. That, indeed, may be no accident. In “Stone Age Death Masks,” author Denise Schmandt-Besserat argues that a series of plaster skulls from the Near East, dating between 7000 B.C. and 5500 B.C., were intended to frighten away evil. To protect themselves, the ancients made plaster casts of actual human skulls because they considered the head the seat of knowledge and power.