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Updated: May 19, 2026
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Operant Procedures for Assessing Behavioral Flexibility in Rats
Published on: February 15, 2015
Evidence of the conjunction fallacy in Rats (Rattus norvegicus) following two-lever choice training
Kayley M Ozimac1, Valeria V Gonzalez2, Aaron P Blaisdell1
1Department of Psychology, University of California, Los Angeles.
Summary
Rats exhibit the conjunction fallacy, a cognitive bias where they judge combined events as more likely than individual ones. This study confirmed this bias in rats using a new procedure, enabling parallel research with humans.
Area of Science:
- Cognitive Psychology
- Animal Behavior
- Decision Making
Background:
- The conjunction fallacy is a well-documented cognitive bias in humans.
- Previous research indicated that rats also display this bias.
- A prior study used a go/no-go procedure, which may introduce reward-based biases.
Purpose of the Study:
- To replicate the conjunction fallacy in rats.
- To eliminate potential reward asymmetry biases.
- To establish a foundation for comparative studies in rats and humans.
Main Methods:
- A 2-alternative choice procedure was employed.
- Reinforcement was consistently available across all trial types.
- This method aimed to remove reward-based attentional biases.
Main Results:
- Rats demonstrated a significant conjunction fallacy.
- The results replicated previous findings.
- The bias was observed even when reward asymmetry was controlled.
Conclusions:
- The conjunction fallacy is present in rats.
- The 2-alternative choice procedure effectively controls for reward bias.
- This research facilitates direct comparisons of cognitive biases between rats and humans.
