ABA Fundamentals

Optimization and the matching law as accounts of instrumental behavior.

Baum (1981) · Journal of the experimental analysis of behavior 1981
★ The Verdict

Pick matching for concurrent schedules and maximizing for single schedules, but know newer math can unite them.

✓ Read this if BCBAs writing concurrent-schedule assessments or teaching choice-making to learners with developmental disabilities.
✗ Skip if Clinicians who only run discrete-trial or purely DRA programs without concurrent contingencies.

01Research in Context

01

What this study did

Allen (1981) compared two big ideas about why we do what we do. One idea says we match our behavior to the pay-off rates. The other says we always pick the richest single option.

The paper looked at which idea fits best under different lab schedules. It asked: does matching or maximizing better explain pigeons pressing levers for food?

02

What they found

Matching won for concurrent schedules. When two choices run at the same time, birds split their responses to match the payoff rates.

Maximizing won for single schedules. When only one option is open, birds press at the rate that pulls the most food.

03

How this fits with other research

Mates (1990) later showed the fight was a false alarm. Under concurrent-chains, the math of matching and maximizing can collapse into the same formula.

Avellaneda et al. (2025) now supersedes the old rule. Their new matching law lets sensitivity drift with overall rate, giving tighter fits than the 1981 version.

Hoch et al. (2007) extends the idea to people. They tracked how adults with developmental disabilities split their problem behavior versus polite bids for staff attention. The same matching equation fit the real-world data.

04

Why it matters

You now have a quick decision tree. Use matching when you run concurrent reinforcement like choice sessions or competing schedules of attention. Use maximizing when you shape a single skill and want the highest rate of reinforcement possible. Keep changeover delays short or matching will flatten. And if the data look off, try the newer rate-sensitive matching form instead of forcing the 1981 classic.

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Plot your client’s two response options as relative rates; if the data points sit on the diagonal, matching is at work and you can adjust reinforcement ratios to shift behavior.

02At a glance

Intervention
not applicable
Design
theoretical
Finding
not reported

03Original abstract

The interaction between instrumental behavior and environment can be conveniently described at a molar level as a feedback system. Two different possible theories, the matching law and optimization, differ primarily in the reference criterion they suggest for the system. Both offer accounts of most of the known phenomena of performance on concurrent and single variable-interval and variable-ratio schedules. The matching law appears stronger in describing concurrent performances, whereas optimization appears stronger in describing performance on single schedules.

Journal of the experimental analysis of behavior, 1981 · doi:10.1901/jeab.1981.36-387