Noncriterial behavioral variability and related topographic bias in humans

ABSTRACT All operant behaviors have multiple characteristics in addition to those criterial for reinforcement, and variation occurs across all. All such characteristics can also reflect topographic bias due to historic and physiological factors. The revealed operant is constructed so that topographic aspects and variation are measurable. In two experiments humans performed a revealed operant response of 14 or more keystrokes. The first and last were mandated, while the middle 12 or more were allowed to vary. There were significant differences in variability among participants, as well as systematic effects of the experimental designs. Despite not being reinforced, variability among complete sequences was high. Test conditions in Experiment 2 resulted in a much larger increase in variability than did suspension of reinforcement in Experiment 1. There was systematic topographic bias both for and against letter keys in the center of the keyboard. There were also correlations between measures of variability and bias.