The reward value of getting out of a starting box: Further extensions of Zimmerman’s work

Four control groups without secondary reinforcement training were tested in a Zimmerman Skinner box-runway apparatus. Two control groups, which were permitted to leave the box after bar pressing, pressed the bar as often as an experimental group with Sr training. The other two control groups, which were confined in the goal box after bar pressing, made significantly fewer bar presses. Zimmerman’s Sr interpretation of his results was questioned …