Violations of stochastic transitivity on concurrent chains: Implications for theories of choice.
Circular choices in two-step schedules can be procedural artifacts, not proof of complex reinforcer dimensions.
01Research in Context
What this study did
Pfadt (1991) looked at odd choice patterns in concurrent-chain schedules. These are the two-step schedules you use in preference assessments.
The paper asked: when pick-A-over-B and B-over-C, why do some pigeons later pick C over A? This breaks a rule called stochastic transitivity.
Instead of adding new reward dimensions, the author blamed the procedure itself.
What they found
The math showed that small changes in chain links can flip apparent preference.
So the "violation" may be a measurement glitch, not a true mental U-turn.
How this fits with other research
Hatton et al. (1999) ran hens on simple concurrent ratios and got perfect transitivity. The birds always picked the smaller response requirement. This seems to clash with Pfadt (1991), but the hens never saw the two-step chain structure that can hide reinforcer delays.
Gillberg (1993) kept the one-dimensional view but added schedule interdependence. His contextual matching rule predicts when transitivity will break and when it will hold, building directly on Pfadt (1991).
Pisacreta (1982) supplied the earlier incentive model that A uses. The core idea—value equals reduced delay to food—stays the same; A just shows it can fake intransitivity if the chain links shift.
Houston et al. (1987) warn that low switch rates can make allocation look odd even when preference is stable. Together with A, the message is: check the procedure before you check the organism.
Why it matters
For BCBAs, the paper is a caution flag. If a child picks bubbles over blocks, blocks over trains, but then trains over bubbles, do not rush to say reinforcement is "multidimensional." Look at your chain first. Did the terminal delay change? Did the initial-link schedule shift? Fix the procedure and the circular preference may vanish, saving you from unnecessary program rewrites.
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02At a glance
03Original abstract
The concurrent-chains procedure has been used to measure how choice depends on various aspects of reinforcement, such as its delay and its magnitude. Navarick and Fantino (1972, 1974, 1975) have found that choice in this procedure can violate the condition of stochastic transitivity that is required if a unidimensional scale for reinforcements is to be possible. It is shown in this paper that two simple unidimensional models of choice on concurrent chains can produce violations of stochastic transitivity. It is argued that such violations may result from the complex contingencies of the concurrent-chains procedure.
Journal of the experimental analysis of behavior, 1991 · doi:10.1901/jeab.1991.55-323