title: Feature- versus rule-based generalization in rats, pigeons and humans.
abstract: Humans can spontaneously create rules that allow them to efficiently generalize what they have learned to novel situations. An enduring question is whether rule-based generalization is uniquely human or whether other animals can also abstract rules and apply them to novel situations. In recent years, there have been a number of high-profile claims that animals such as rats can learn rules. Most of those claims are quite weak because it is possible to demonstrate that simple associative systems (which do not learn rules) can account for the behavior in those tasks. Using a procedure that allows us to clearly distinguish feature-based from rule-based generalization (the Shanks-Darby procedure), we demonstrate that adult humans show rule-based generalization in this task, while generalization in rats and pigeons was based on featural overlap between stimuli. In brief, when learning that a stimulus made of two components ("AB") predicts a different outcome than its elements ("A" and "B"), people spontaneously abstract an opposites rule and apply it to new stimuli (e.g., knowing that "C" and "D" predict one outcome, they will predict that "CD" predicts the opposite outcome). Rats and pigeons show the reverse behavior-they generalize what they have learned, but on the basis of similarity (e.g., "CD" is similar to "C" and "D", so the same outcome is predicted for the compound stimulus as for the components). Genuinely rule-based behavior is observed in humans, but not in rats and pigeons, in the current procedure.
authors.affiliation: KU Leuven, Tiensestraat 102, Box 3712, 3000, Leuven, Belgium.
authors.forename: Elisa
authors.initials: E
authors.lastname: Maes
authors.affiliation: Università di Bologna, Via Zamboni 33, 40126, Bologna, Italy.|Washington Singer Laboratories, University of Exeter, Exeter, EX4 4QG, UK.
authors.forename: Guido
authors.initials: G
authors.lastname: De Filippo
authors.affiliation: Plymouth University, Drake Circus, Plymouth, PL4 8AA, UK.
authors.forename: Angus B
authors.initials: AB
authors.lastname: Inkster
authors.affiliation: Washington Singer Laboratories, University of Exeter, Exeter, EX4 4QG, UK.
authors.forename: Stephen E G
authors.initials: SE
authors.lastname: Lea
authors.affiliation: Ghent University, Henri Dunantlaan 2, 9000, Ghent, Belgium.
authors.forename: Jan
authors.initials: J
authors.lastname: De Houwer
authors.affiliation: KU Leuven, Tiensestraat 102, Box 3714, 3000, Leuven, Belgium.
authors.forename: Rudi
authors.initials: R
authors.lastname: D'Hooge
authors.affiliation: KU Leuven, Tiensestraat 102, Box 3712, 3000, Leuven, Belgium. tom.beckers@ppw.kuleuven.be.|University of Amsterdam, Weesperplein 4, 1018XA, Amsterdam, The Netherlands. tom.beckers@ppw.kuleuven.be.
authors.forename: Tom
authors.initials: T
authors.lastname: Beckers
authors.affiliation: Plymouth University, Drake Circus, Plymouth, PL4 8AA, UK. andy@willslab.co.uk.
authors.forename: Andy J
authors.initials: AJ
authors.lastname: Wills
mesh_terms: D000818:Animals; D001245:Association Learning; D010856:Columbidae / Q000502:physiology*; D004193:Discrimination Learning; D005260:Female; D005793:Generalization, Psychological; D006801:Humans; D008297:Male; D010364:Pattern Recognition, Visual; D051381:Rats / Q000502:physiology*; D017207:Rats, Sprague-Dawley; D055815:Young Adult
keywords: Associative models; Generalization; Humans; Pigeons; Rats; Rule-based