Originally, ten subjects, all but one of whom were confederates with the experimenter, were shown pairs of cards and asked to make perceptual judgments.  
Variants of this experiment included having the subject arrive late and being told to write his answers down in private, which led to little yielding; or having a confederate act as the subject's ally.  Originally, ten subjects, all but one of whom were confederates with the experimenter, were shown pairs of cards and asked to make perceptual judgments.  The confederates would give false answers, inducing many subjects to yield to the group.  FTP, identify this classic experiment that suggests that our notion of physical reality is influenced by mutual agreement with others.
Variants of this experiment included having the subject arrive late and being told to write his answers down in private, which led to little yielding; or having a confederate act as the subject's ally.  
Solomon Asch's experiment