 In their early work, Lorenz and Tinbergen drew a sharp distinction between innate vs acquired behavior. An innate behavior was thought to be, (1) stereotyped or constant in form, (2) species-typical, (3) capable of developing in socially isolated animals, and (4) capable of developing “fully formed” in animals which had been deprived of opportunities to practice it (Lehrman 1953). Early ethologists placed considerable emphasis on the ‘deprivation experiment’ as a method for distinguishing innate from acquired behaviors. These experiments involved raising an animal without the opportunity to learn a behavior and then testing to see if it can perform the behavior when provided with an appropriate stimulus. A songbird, for example, can be raised from egg to adult without hearing a member of its own species sing, and tested to see which song it produces the following spring. If it produces the typical song of its own species, then the song was deemed innate. For more on Lorenz and Tinbergen’s ideas about instinct, see (Richards 1974; Griffiths 2004; Brigandt 2005; Browne 2005; Burkhardt 2005).