title: Using the Aesop's fable paradigm to investigate causal understanding of water displacement by New Caledonian crows.
abstract: Understanding causal regularities in the world is a key feature of human cognition. However, the extent to which non-human animals are capable of causal understanding is not well understood. Here, we used the Aesop's fable paradigm--in which subjects drop stones into water to raise the water level and obtain an out of reach reward--to assess New Caledonian crows' causal understanding of water displacement. We found that crows preferentially dropped stones into a water-filled tube instead of a sand-filled tube; they dropped sinking objects rather than floating objects; solid objects rather than hollow objects, and they dropped objects into a tube with a high water level rather than a low one. However, they failed two more challenging tasks which required them to attend to the width of the tube, and to counter-intuitive causal cues in a U-shaped apparatus. Our results indicate that New Caledonian crows possess a sophisticated, but incomplete, understanding of the causal properties of displacement, rivalling that of 5-7 year old children.
authors.affiliation: Department of Psychology, University of Auckland, Auckland, New Zealand.
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Jelbert
authors.affiliation: Department of Psychology, University of Auckland, Auckland, New Zealand.
authors.forename: Alex H
authors.initials: AH
authors.lastname: Taylor
authors.affiliation: Department of Psychology, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Lucy G
authors.initials: LG
authors.lastname: Cheke
authors.affiliation: Department of Psychology, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Nicola S
authors.initials: NS
authors.lastname: Clayton
authors.affiliation: Department of Psychology, University of Auckland, Auckland, New Zealand.
authors.forename: Russell D
authors.initials: RD
authors.lastname: Gray
mesh_terms: D000818:Animals; D001045:Aphorisms and Proverbs as Topic; D046368:Crows / Q000502:physiology*; D009510:New Caledonia; D014867:Water
chemical_list: D014867:Water