More on concurrent interval-ratio schedules: a replication and review.

Area of Science:

• Behavioral psychology
• Animal behavior studies

Background:

• Concurrent schedules of reinforcement are crucial for understanding choice behavior.
• Previous studies suggest response costs may influence reinforcement maximization, but these costs are often unmeasured.

Purpose of the Study:

• To investigate if pigeons optimize reinforcement by balancing benefits against response costs.
• To evaluate pigeon behavior on concurrent schedules with equal response costs.

Main Methods:

• Pigeons were tested using a concurrent variable time (VT) and variable ratio-time (VRT) schedule.
• This procedure equalized response costs between schedule alternatives, isolating reinforcement rate effects.
• Reinforcement delivery was independent of response, with a changeover key controlling schedule access.

Main Results:

• Pigeons did not maximize their overall rate of reinforcement.
• Pigeon's time allocation across schedules matched the relative rates of reinforcement.
• This matching behavior persisted even when it resulted in the lowest possible overall reinforcement rate.

Conclusions:

• The findings challenge the assumption that subjects fail to maximize reinforcement due to unmeasured response costs.
• Pigeons exhibit matching behavior on concurrent schedules, allocating time in proportion to reinforcement rates, irrespective of overall rate maximization.
• The observed matching is not an artifact of the experimental procedure.