Human Performance Under Sequences of Fixed-Ratio Schedules: Effects of Ratio Size and Magnitude of Reinforcement

In a discrete-trials procedure, adult humans chose between two sequential fixed-ratio (FR) schedules. Points, later exchangeable for money, were given for the completion of each FR. When each sequence produced two points for an equal number of responses overall, the value of the first FR in a sequence did not affect choice. When the values of the first FR in each sequence were equal, subjects preferred the alternative with the smaller second FR. Once a preference was established for the alternative with the smaller overall response requirement, two points were given for completing the second FR of the nonpreferred sequence. This sequence then provided three total points. Preference immediately shifted to the alternative requiring more responses overall (and per point) but offering more points.