Preference for Terminal-Link Key Pecking in Concurrent Homogeneous and Heterogeneous Chains

Abstract

The response topographies required in the various components of chain schedules may be similar (homogeneous) or dissimilar (heterogeneous). Previous studies have shown initial-link responding to be increased under homogeneous chains compared to otherwise identical heterogeneous chains. Among the factors that have been proposed to account for this are induction, in which the effect of reinforcing a particular response topography generalizes to similar responses earlier in the chain, and the nature (e.g., effort) of the terminal-link topographies themselves. Prior investigations have used single-response procedures which preclude the empirical assessment of preference. The present study employed a concurrent-chains procedure and found increased response rates and time allocation to the alternative correlated with terminal-link pecking. This indicates that terminal-link pecking is preferred over terminal-link treadling and that response topography itself is a critical variable in determining initial-link performance when responses of different topographies are arranged in the terminal links. In addition, these data suggest that certain quantitative formulations of choice may be inadequate in predicting performance under concurrent schedules when topographically dissimilar responses are required.