A functional analysis of another individual's behavior as discriminative stimulus for a monkey.

Key presses of 1 monkey (called the performer) became the basis upon which a 2nd monkey (called the judge) solved conditional-discrimination tasks. First, the performer was trained to press one of two colored choice keys (red or green) depending on the location of a white light in her chamber. The performer's key-pressing behavior was brought under the control of the experimenter by this procedure. Subsequently, the judge was trained to discriminate the performer's key-pressing behavior. In Experiment 1, the judge had to press Key 1 when the performer pressed the red choice key and Key 2 when the performer pressed the green choice key. In Experiment 2, a sample key was introduced. The judge had to press Key 1 when the performer pressed the same colored choice key as the sample; the judge had to press Key 2 when the performer pressed the different colored choice key. In both experiments, the judge was required to attend to the behavior of the performer. It was shown that the performer's behavior served as a discriminative stimulus for the judge's responses in a conditional-discrimination task.