ABSTRACT
Mowrer (1950, chap. 24) states that sounds must be associated with reinforcement for talking birds to imitate them. In his most recent formulation (Mowrer, 1960) the rea soning is as follows: if any stimulus, for instance the sight of a human being, is repeatedly associated with a primary reinforcer (e.g., food) then the appearance of the human will give rise to "hope," which in turn is reinforcing; if the human repeatedly ut ters a given sound, that sound will also produce hope; if now the bird, in the course of its babbling, makes noises which approxi mate those produced by the human, these will produce hope, and the production of the noises will be reinforced-the more so the more the noises approach the human version.
