title: Comparing humans and nonhuman great apes in the broken cloth problem: Is their knowledge causal or perceptual?
abstract: When presented with the broken cloth problem, both human children and nonhuman great apes prefer to pull a continuous cloth over a discontinuous cloth in order to obtain a desired object resting on top. This has been interpreted as evidence that they preferentially attend to the functionally relevant cues of the task (e.g., presence or absence of a gap along the cloth). However, there is controversy regarding whether great apes' behavior is underpinned by causal knowledge, involving abstract concepts (e.g., support, connection), or by perceptual knowledge, based on percepts (e.g., contact, continuity). We presented chimpanzees, orangutans, and 2-, 3-, and 4-year-old children with two versions of the broken cloth problem. The Real condition, made with paper strips, could be solved based on either perceptual cues or causal knowledge. The Painted condition, which looked very similar, could be solved only by attending to perceptual cues. All groups mastered the Real condition, in line with previous results. Older children (3- and 4-year-olds) performed significantly better in this condition than all other groups, but the performance of apes and children did not differ sharply, with 2-year-olds and apes obtaining similar results. In contrast, only 4-year-olds solved the Painted condition. We propose causal knowledge to explain the general good performance of apes and humans in the Real condition compared with the Painted condition. In addition, we suggest that symbolic knowledge might account for 4-year-olds' performance in the Painted condition. Our findings add to the growing literature supporting the idea that learning from arbitrary cues is not a good explanation for the performance of apes and humans on some kinds of physical task.
authors.affiliation: Department of Developmental and Comparative Psychology, Max Planck Institute for Evolutionary Anthropology, 04103 Leipzig, Germany; Departamento de Psicobiología, Facultad de Psicología, Universidad Complutense de Madrid, Campus de Somosaguas, 28223 Madrid, Spain; Unidad de Etología y Bienestar Animal, Facultad de Veterinaria, Universidad CEU Cardenal Herrera, 46115 Valencia, Spain. Electronic address: anna.albiach@uch.ceu.es.
authors.forename: Anna
authors.initials: A
authors.lastname: Albiach-Serrano
authors.affiliation: Departamento de Psicobiología, Facultad de Psicología, Universidad Complutense de Madrid, Campus de Somosaguas, 28223 Madrid, Spain.
authors.forename: Carla
authors.initials: C
authors.lastname: Sebastián-Enesco
authors.affiliation: Department of Developmental and Comparative Psychology, Max Planck Institute for Evolutionary Anthropology, 04103 Leipzig, Germany; School of Psychology and Neuroscience, University of St. Andrews, St. Andrews, Fife KY16 9JP, UK.
authors.forename: Amanda
authors.initials: A
authors.lastname: Seed
authors.affiliation: Departamento de Psicobiología, Facultad de Psicología, Universidad Complutense de Madrid, Campus de Somosaguas, 28223 Madrid, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Colmenares
authors.affiliation: Department of Developmental and Comparative Psychology, Max Planck Institute for Evolutionary Anthropology, 04103 Leipzig, Germany; School of Psychology and Neuroscience, University of St. Andrews, St. Andrews, Fife KY16 9JP, UK.
authors.forename: Josep
authors.initials: J
authors.lastname: Call
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D002652:Child Behavior / Q000523:psychology*; D002675:Child, Preschool; D005260:Female; D006801:Humans; D019359:Knowledge; D007858:Learning; D008297:Male; D002679:Pan troglodytes / Q000523:psychology*; D011148:Pongo pygmaeus / Q000523:psychology*; D011340:Problem Solving / Q000502:physiology*
keywords: Associative learning; Broken cloth problem; Causal knowledge; Children; Chimpanzees; Orangutans