Hostname: page-component-78c5997874-fbnjt Total loading time: 0 Render date: 2024-11-06T10:54:00.135Z Has data issue: false hasContentIssue false

Darwin's triumph: Explaining the uniqueness of the human mind without a deus ex machina

Published online by Cambridge University Press:  14 May 2008

Derek C. Penn
Affiliation:
Department of Psychology, University of California–Los Angeles, Los Angeles, CA 90095 Cognitive Evolution Group, University of Louisiana, Lafayette, LA 70504. [email protected] [email protected] [email protected]://www.cognitiveevolutiongroup.org/http://reasoninglab.psych.ucla.edu/
Keith J. Holyoak
Affiliation:
Department of Psychology, University of California–Los Angeles, Los Angeles, CA 90095
Daniel J. Povinelli
Affiliation:
Cognitive Evolution Group, University of Louisiana, Lafayette, LA 70504. [email protected] [email protected] [email protected]://www.cognitiveevolutiongroup.org/http://reasoninglab.psych.ucla.edu/

Abstract

In our target article, we argued that there is a profound functional discontinuity between the cognitive abilities of modern humans and those of all other extant species. Unsurprisingly, our hypothesis elicited a wide range of responses from commentators. After responding to the commentaries, we conclude that our hypothesis lies closer to Darwin's views on the matter than to those of many of our contemporaries.

Type
Authors' Response
Copyright
Copyright ©Cambridge University Press 2008

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Adler, M. J. (1968) The difference of man and the difference it makes. University of Chicago Press.Google Scholar
Andrews, G. & Halford, G. S. (2002) A cognitive complexity metric applied to cognitive development. Cognitive Psychology 45(2):153219.CrossRefGoogle ScholarPubMed
Andrews, G., Halford, G. S., Bunch, K. M., Bowden, D. & Jones, T. (2003) Theory of mind and relational complexity. Child Development 74(5):1476–99.CrossRefGoogle ScholarPubMed
Barrett, H. C. & Kurzban, R. (2006) Modularity in cognition: Framing the debate. Psychological Review 113:628–47.CrossRefGoogle ScholarPubMed
Bergman, T. J., Beehner, J. C., Cheney, D. L. & Seyfarth, R. M. (2003) Hierarchical classification by rank and kinship in baboons. Science 302(5648):1234–36.CrossRefGoogle ScholarPubMed
Bermúdez, J. L. (2003) Thinking without words Oxford University Press.CrossRefGoogle Scholar
Bermúdez, J. L. (2005) Philosophy of psychology: A contemporary introduction Routledge.Google Scholar
Bloom, P. (2000) Language and thought: Does grammar makes us smart? Current Biology 10(14):R516–17.CrossRefGoogle ScholarPubMed
Call, J. & Tomasello, M. (1999) A nonverbal false belief task: The performance of children and great apes. Child Development 70(2):381–95.CrossRefGoogle ScholarPubMed
Carruthers, P. (2002) The cognitive functions of language. Behavioral and Brain Sciences 25(6):657726.CrossRefGoogle ScholarPubMed
Carruthers, P. (2005a) Distinctively human thinking: Modular precursors and components. In: The innate mind: Structure and content, ed. Carruthers, P., Laurence, S. & Stich, S. P., pp. 6988. Oxford University Press.CrossRefGoogle Scholar
Carruthers, P. & Smith, P. K., eds. (1996) Theories of theory of mind Cambridge University Press.CrossRefGoogle Scholar
Clark, A. (2001) Reasons, robots and the extended mind. Mind and Language 16(2):121–45.CrossRefGoogle Scholar
Clark, A. & Thornton, C. (1997) Trading spaces: Computation, representation, and the limits of uninformed learning. Behavioral and Brain Sciences 20:5790.CrossRefGoogle ScholarPubMed
Cook, R. G. & Wasserman, E. A. (2006) Relational discrimination learning in pigeons. In: Comparative cognition: Experimental explorations in animal intelligence, ed. Wasserman, E. A. & Zentall, T. R., pp. 307–24. Oxford University Press.Google Scholar
Cook, R. G. & Wasserman, E. A. (in press) Discrimination and transfer of higher-order same/different relations by pigeons. Psychonomic Bulletin and ReviewGoogle Scholar
Corballis, M. C. (2007a) Recursion, language, and starlings. Cognitive Science 31:697704.CrossRefGoogle ScholarPubMed
Dally, J. M., Emery, N. J. & Clayton, N. S. (2006) Food-caching western scrub-jays keep track of who was watching when. Science 312(5780):1662–65.CrossRefGoogle Scholar
Darwin, C. (1859) On the origin of species John Murray.Google Scholar
Darwin, C. (1871) The descent of man, and selection in relation to sex. John Murray.Google Scholar
De Marco, R. & Menzel, R. (2005) Encoding spatial information in the waggle dance. Journal of Experimental Biology 208(20):3885–94.CrossRefGoogle ScholarPubMed
Dennett, D. C. (1996) Kinds of minds: Toward an understanding of consciousness, 1st edition. Basic Books.Google Scholar
Doumas, L. A. & Hummel, J. E. (2005) Approaches to modeling human mental representations: What works, what doesn't and why. In: The Cambridge handbook of thinking and reasoning, ed. Holyoak, K. J. & Morrison, R. G., pp. 7394. Cambridge University Press.Google Scholar
Doumas, L. A. A., Hummel, J. E. & Sandhofer, C. M. (2008) A theory of the discovery and predication of relational concepts. Psychological Review 115:143.CrossRefGoogle ScholarPubMed
Emery, N. J. (2004) Are corvids “feathered apes”? Cognitive evolution in crows, jays, rooks and jackdaws. In: Comparative analysis of minds, ed. Watanabe, S., pp. 181213. Keio University Press.Google Scholar
Emery, N. J. & Clayton, N. S. (2001) Effects of experience and social context on prospective caching strategies by scrub-jays. Nature 414:443–46.CrossRefGoogle ScholarPubMed
Emery, N. J. & Clayton, N. S. (2004b) The mentality of crows: Convergent evolution of intelligence in corvids and apes. Science 306(5703):1903–907.CrossRefGoogle ScholarPubMed
Emery, N. J. & Clayton, N. S. (in press) How to build a scrub-jay that reads minds. In: Origins of the social mind: Evolutionary and developmental views, ed. Itakura, S. & Fujita, K.. Springer.Google Scholar
Fragaszy, D. M., Galloway, A. T., Johnson-Pynn, J. & Brakke, K. (2002) The sources of skill in seriating cups in children, monkeys and apes. Developmental Science 5(1):118–31.CrossRefGoogle Scholar
Fries, P., Nikolic, D. & Singer, W. (2007) The gamma cycle. Trends in Neuroscience 30(7):309–16.CrossRefGoogle ScholarPubMed
Gentner, D. (1977) If a tree had a knee, where would it be? Children's performance on simple spatial metaphors. Papers and Reports on Child Language Development 13:157–64.Google Scholar
Gentner, D. (1983) Structure-mapping: A theoretical framework for analogy. Cognitive Science 7:155–70.Google Scholar
Gentner, D. (2003) Why we're so smart. In: Language in mind: Advances in the study of language and thought, ed. Gentner, D. & Goldin-Meadow, S., pp. 195235. MIT Press.CrossRefGoogle Scholar
Gentner, D. & Markman, A. B. (1997) Structure mapping in analogy and similarity. American Psychologist 52:4556.CrossRefGoogle Scholar
Gentner, T. Q., Fenn, K. M., Margoliash, D. & Nusbaum, H. C. (2006) Recursive syntactic pattern learning by songbirds. Nature 440(7088):1204–207.CrossRefGoogle ScholarPubMed
Gibson, B. M. & Wasserman, E. A. (2004) Time-course of control by specific stimulus features and relational cues during same-different discrimination training. Learning and Behavior 32(2):183–89.CrossRefGoogle ScholarPubMed
Gillan, D. J., Premack, D. & Woodruff, G. (1981) Reasoning in the chimpanzee: I. Analogical reasoning. Journal of Experimental Psychology: Animal Behavior Processes 7:117.Google Scholar
Gomez, R. L. & Gerken, L. (2000) Infant artificial language learning and language acquisition. Trends in Cognitive Sciences 4(5):178–86.CrossRefGoogle ScholarPubMed
Gopnik, A., Glymour, C., Sobel, D., Schulz, L., Kushnir, T. & Danks, D. (2004) A theory of causal learning in children: Causal maps and Bayes nets. Psychological Review 111(1):131.CrossRefGoogle ScholarPubMed
Greenfield, P. M. (1991) Language, tools and the brain: The ontogeny and phylogeny of hierarchically organized sequential behavior. Behavioral and Brain Sciences 14:531–95.CrossRefGoogle Scholar
Grosenick, L., Clement, T. S. & Fernald, R. D. (2007) Fish can infer social rank by observation alone. Nature 445(7126):429–32.CrossRefGoogle ScholarPubMed
Hadley, R. F. (1999) Connectionism and novel combinations of skills: Implications for cognitive architecture. Minds and Machines 9:197221.CrossRefGoogle Scholar
Halford, G. S. (1984) Can young children integrate premises in transitivity and serial order tasks? Cognitive Psychology 16:6593.CrossRefGoogle Scholar
Halford, G. S., Baker, R., McCredden, J. E. & Bain, J. D. (2005) How many variables can humans process? Psychological Science 16(1):7076.CrossRefGoogle ScholarPubMed
Halford, G. S. & Busby, J. (2007) Acquisition of structured knowledge without instruction: The relational schema induction paradigm. Journal of Experimental Psychology: Learning, Memory and Cognition 33:586603.Google ScholarPubMed
Halford, G. S., Wilson, W. H. & Phillips, S. (1998a) Processing capacity defined by relational complexity: Implications for comparative, developmental, and cognitive psychology. Behavioral and Brain Sciences 21(6):803–31; discussion 831–64.CrossRefGoogle ScholarPubMed
Hauser, M. D., Chomsky, N. & Fitch, W. T. (2002a) The faculty of language: What is it, who has it and how did it evolve? Science 298(5598):1569–79.CrossRefGoogle ScholarPubMed
Hempel, C. G. (1965) Aspects of scientific explanation and other essays in the philosophy of science Free Press.Google Scholar
Herman, L. M. (2006) Intelligence and rational behavior in the bottlenosed dolphin. In: Rational animals?, ed. Hurley, S. & Nudds, M., pp. 439–67. Oxford University Press.CrossRefGoogle Scholar
Herman, L. M., Richards, D. G. & Wolz, J. P. (1984) Comprehension of sentences by bottlenosed dolphins. Cognition 16:129219.CrossRefGoogle ScholarPubMed
Heyes, C. M. (1998) Theory of mind in nonhuman primates. Behavioral and Brain Sciences 21(1):101–14; discussion 115–48.CrossRefGoogle ScholarPubMed
Holyoak, K. J. & Hummel, J. E. (2000) The proper treatment of symbols in a connectionist architecture. In: Cognitive dynamics: Conceptual change in humans and machines, ed. Dietrich, E. & Markman, A. B., pp. 229–63. Erlbaum.Google Scholar
Holyoak, K. J., Junn, E. N. & Billman, D. (1984) Development of analogical problem-solving skill. Child Development 55:2042–55.CrossRefGoogle ScholarPubMed
Holyoak, K. J. & Thagard, P. (1995) Mental leaps: Analogy in creative thought MIT Press.Google Scholar
Horgan, T. & Tienson, J. (1996) Connectionism and the philosophy of psychology MIT Press.CrossRefGoogle Scholar
Hummel, J. E. & Holyoak, K. J. (1997) Distributed representations of structure: A theory of analogical access and mapping. Psychological Review 104:427–66.CrossRefGoogle Scholar
Hummel, J. E. & Holyoak, K. J. (2003) A symbolic-connectionist theory of relational inference and generalization. Psychological Review 110:220–64.CrossRefGoogle ScholarPubMed
Huttenlocher, J., Newcombe, N. & Vasilyeva, M. (1999) Spatial scaling in young children. Psychological Science 10:393–98.CrossRefGoogle Scholar
Inhelder, B. & Piaget, J. (1964) The early growth of logic in the child Routledge and Kegan-Paul.Google Scholar
Kuhlmeier, V. A. & Boysen, S. T. (2002) Chimpanzees (Pan troglodytes) recognize spatial and object correspondences between a scale model and its referent. Psychological Science 13(1):6063.CrossRefGoogle ScholarPubMed
Lagnado, D. A., Waldmann, M. R., Hagmayer, Y. & Sloman, S. A. (2005) Beyond covariation: Cues to causal structure. In: Causal learning: Psychology, philosophy and computation, ed. Gopnik, A. & Schultz, L., pp. 154–72. Oxford University Press.Google Scholar
Lazareva, O. F., Smirnova, A. A., Bagozkaja, M. S., Zorina, Z. A., Rayevsky, V. V. & Wasserman, E. A. (2004) Transitive responding in hooded crows requires linearly ordered stimuli. Journal of Experimental Analysis of Behavior 82(1):119.CrossRefGoogle ScholarPubMed
Marcus, G. F. (2006) Startling starlings. Nature 440:1117–18.CrossRefGoogle ScholarPubMed
Marr, D. (1982) Vision: A computational investigation into the human representation and processing of visual information W. H. Freeman.Google Scholar
Matsuzawa, T. (1996) Chimpanzee intelligence in nature and in captivity: Isomorphism of symbol use and tool use. In: Great ape societies, ed. McGrew, W. C., Marchant, L. F. & Nishida, T., pp. 196209. Cambridge University Press.CrossRefGoogle Scholar
McGonigle, B., Chalmers, M. & Dickinson, A. (2003) Concurrent disjoint and reciprocal classification by Cebus apella in seriation tasks: Evidence for hierarchical organization. Animal Cognition 6(3):185–97.CrossRefGoogle ScholarPubMed
Newell, A. (1990) Unified theories of cognition Harvard University Press.Google Scholar
Oden, D. L., Thompson, R. K. R. & Premack, D. (2001) Can an ape reason analogically? Comprehension and production of analogical problems by Sarah, a chimpanzee (Pan troglodytes). In: The analogical mind, ed. Gentner, D., Holyoak, K. J. & Kokinov, B. N., pp. 471–98. MIT Press.CrossRefGoogle Scholar
Otter, K. A., McGregor, P. K., Terry, A. M. R., Burford, F. R. L., Peake, T. M. & Dabelsteen, T. (1999) Do female great tits Parus major assess males by eavesdropping? A field study using interactive song playback. Proceedings of the Royal Society, London B 266(1426):1035.CrossRefGoogle Scholar
Pack, A. A. & Herman, L. M. (2006) Dolphin social cognition and joint attention: Our current understanding. Aquatic Mammals 32(4):443–60.CrossRefGoogle Scholar
Paz, Y. M. C. G., Bond, A. B., Kamil, A. C. & Balda, R. P. (2004) Pinyon jays use transitive inference to predict social dominance. Nature 430(7001):778–81.CrossRefGoogle Scholar
Peake, T. M., Terry, A. M., McGregor, P. K. & Dabelsteen, T. (2002) Do great tits assess rivals by combining direct experience with information gathered by eavesdropping? Proceedings of the Royal Society of London, Series B 269(1503):1925–29.CrossRefGoogle ScholarPubMed
Penn, D. C. & Povinelli, D. J. (2007a) Causal cognition in human and nonhuman animals: A comparative, critical review. Annual Review of Psychology 58:97118.CrossRefGoogle ScholarPubMed
Penn, D. C. & Povinelli, D. J. (2007b) On the lack of evidence that non-human animals possess anything remotely resembling a “theory of mind.” Philosophical Transactions of the Royal Society B 362:731–44.CrossRefGoogle ScholarPubMed
Pepperberg, I. M. (2002) The Alex studies: Cognitive and communicative abilities of grey parrots Harvard University Press.Google ScholarPubMed
Perner, J. & Leekam, S. (2008) The curious incident of the photo that was accused of being false: Issues of domain specificity in development, autism, and brain imaging. The Quarterly Journal of Experimental Psychology 61(1):7689.CrossRefGoogle ScholarPubMed
Pinker, S. & Jackendoff, R. (2005) The faculty of language: What's special about it? Cognition 95:201–36.CrossRefGoogle Scholar
Povinelli, D. J. (2000) Folk physics for apes: The chimpanzee's theory of how the world works Oxford University Press.Google Scholar
Povinelli, D. J. (2001) On the possibilities of detecting intentions prior to understanding them. In: Intentions and intentionality: Foundations of social cognition, ed. Malle, B. F., Baldwin, D. & Moses, L., pp. 225–48. MIT Press.CrossRefGoogle Scholar
Povinelli, D. J. (in preparation) Chimpanzees' understanding of weight [Working Title].Google Scholar
Povinelli, D. J. & Bering, J. M. (2002) The mentality of apes revisited. Current Directions in Psychological Science 11(4):115–19.CrossRefGoogle Scholar
Povinelli, D. J., Bering, J. M. & Giambrone, S. (2000) Toward a science of other minds: Escaping the argument by analogy. Cognitive Science 24(3):509–41.CrossRefGoogle Scholar
Povinelli, D. J. & Eddy, T. J. (1996) What young chimpanzees know about seeing. Monograph of the Society for Research in Child Development 61(3):i–vi, 1–152; discussion 153–91.CrossRefGoogle ScholarPubMed
Povinelli, D. J., Nelson, K. E. & Boysen, S. T. (1992) Comprehension of role reversal in chimpanzees: Evidence of empathy. Animal Behaviour 43:633–40.CrossRefGoogle Scholar
Povinelli, D. J. & Vonk, J. (2003) Chimpanzee minds: Suspiciously human? Trends in Cognitive Sciences 7(4):157–60.CrossRefGoogle ScholarPubMed
Preuss, T. M. (2000) What's human about the human brain? In: The new cognitive neurosciences, ed. Gazzaniga, M. S., pp. xiv, 1419. MIT Press.Google Scholar
Raven, J. C. (1941) Standardization of progressive matrices, 1938. British Journal of Medical Psychology 19:137–50.CrossRefGoogle Scholar
Robin, N. & Holyoak, K. J. (1995) Relational complexity and the functions of the prefrontal cortex. In: The cognitive neurosciences, ed. Gazzaniga, M., pp. 987–97. MIT Press.Google Scholar
Santos, L. R., Pearson, H., Spaepen, G., Tsao, F. & Hauser, M. (2006) Probing the limits of tool competence: Experiments with two non-tool-using species (Cercopithecus aethiops and Saguinus oedipus). Animal Cognition 9(2):94109.CrossRefGoogle ScholarPubMed
Seed, A. M., Tebbich, S., Emery, N. J. & Clayton, N. S. (2006) Investigating physical cognition in rooks (Corvus frugilegus). Current Biology 16:697701.CrossRefGoogle ScholarPubMed
Shanks, D. R. & Darby, R. J. (1998) Feature- and rule-based generalization in human associative learning. Journal of Experimental Psychology: Animal Behavior Processes 24:405–15.Google Scholar
Siegal, M., Varley, R. & Want, S. C. (2001) Mind over grammar: Reasoning in aphasia and development. Trends in Cognitive Sciences 5(7):296301.CrossRefGoogle ScholarPubMed
Silk, J. B. (1999) Male bonnet macaques use information about third-party rank relationships to recruit allies. Animal Behaviour 58:4551.CrossRefGoogle ScholarPubMed
Silk, J. B. (2002b) The form and function of reconciliation in primates. Annual Review of Anthropology 31:2144.CrossRefGoogle Scholar
Silverstein, K. (2007) Rummy in Paris: Democracy is like riding a bike. Harper's Magazine, October 26, 2007. Available at: http://www.harpers.org/archive/2007/10/hbc-90001521.Google Scholar
Smolensky, P. (1999) Grammar-based connectionist approaches to language. Cognitive Science 23(4):589613.Google Scholar
Suddendorf, T. & Whiten, A. (2001) Mental evolution and development: Evidence for secondary representation in children, great apes and other animals. Psychological Bulletin 127:629–50.CrossRefGoogle ScholarPubMed
Tebbich, S., Seed, A. M., Emery, N. J. & Clayton, N. S. (2007) Non-tool-using rooks (Corvus frigilegus) solve the trap-tube task. Animal Cognition 10(2):225–31.CrossRefGoogle Scholar
Tenenbaum, J. B., Griffiths, T. L. & Kemp, C. (2006) Theory-based Bayesian models of inductive learning and reasoning. Trends in Cognitive Sciences 10(7):309–18.CrossRefGoogle ScholarPubMed
Thompson, R. K. R. & Oden, D. L. (2000) Categorical perception and conceptual judgments by nonhuman primates: The paleological monkey and the analogical ape. Cognitive Science 24:363–96. (Special issue on Primate Cognition; guest editor, M. Tomasello.)CrossRefGoogle Scholar
Tomasello, M. (2000) Do young children have adult syntactic competence? Cognition 74(3):209–53.CrossRefGoogle Scholar
Tomasello, M. & Call, J. (1997) Primate cognition Oxford University Press.CrossRefGoogle Scholar
Tomasello, M. & Rakoczy, H. (2003) What makes human cognition unique? From individual to shared to collective intentionality. Mind and Language 18(2):121–47.CrossRefGoogle Scholar
Tschudin, A. (2006) Belief attribution tasks with dolphins: What social minds can reveal about animal rationality. In: Rational animals?, ed. Hurley, S. & Nudds, M., pp. 413–36. Oxford University Press.CrossRefGoogle Scholar
Tunney, R. J. & Altmann, G. T. (2001) Two modes of transfer in artificial grammar learning. Journal of Experimental Psychology: Learning, Memory and Cognition 27(3):614–39.Google ScholarPubMed
Uhlhaas, P. J. & Singer, W. (2006) Neural synchrony in brain disorders: Relevance for cognitive dysfunctions and pathophysiology. Neuron 52(1):155–68.CrossRefGoogle ScholarPubMed
Varley, R. A., Klessinger, N. J., Romanowski, C. A. & Siegal, M. (2005) Agrammatic but numerate. Proceedings of the National Academy of Sciences USA 102(9):3519–24.CrossRefGoogle ScholarPubMed
Varley, R. A. & Siegal, M. (2000) Evidence for cognition without grammar from causal reasoning and “theory of mind” in an agrammatic aphasic patient. Current Biology 10(12):723–26.CrossRefGoogle Scholar
Vasilyeva, M. & Huttenlocher, J. (2004) Early development of scaling ability. Developmental Psychology 40(5):682–90.CrossRefGoogle ScholarPubMed
Vonk, J. & Povinelli, D. J. (2006) Similarity and difference in the conceptual systems of primates: The unobservability hypothesis. In: Comparative cognition: Experimental explorations of animal intelligence, ed. Zentall, T. & Wasserman, E. A., pp. 363–87. Oxford University Press.Google Scholar
Waltz, J. A., Knowlton, B. J., Holyoak, K. J., Boone, K. B., Back-Madruga, C., McPherson, S., Masterman, D., Chow, T., Cummings, J. L. & Miller, B. L. (2004) Relational integration and executive function in Alzheimer's disease. Neuropsychology 18(2):296305.CrossRefGoogle ScholarPubMed
Waltz, J. A., Knowlton, B. J., Holyoak, K. J., Boone, K. B., Mishkin, F. S., Santos, M. de M., Thomas, C. R. & Miller, B. L. (1999) A system for relational reasoning in human prefrontal cortex. Psychological Science 10(2):119–25.CrossRefGoogle Scholar
Whiten, A., Custance, D. M., Gomez, J. C., Texidor, P. & Bard, K. A. (1996) Imitative learning of artificial fruit processing in children (Homo sapiens) and chimpanzees (Pan troglodytes). Journal of Comparative Psychology 110:314.CrossRefGoogle ScholarPubMed
Wilson, W. H., Halford, G. S., Gray, B. & Phillips, S. (2001a) The STAR-2 model for mapping hierarchically structured analogs. In: The analogical mind, ed. Gentner, D., Holyoak, K. J. & Kokinov, B. N., pp. 125–60. MIT Press.CrossRefGoogle Scholar
Wilson, W. H., Marcus, N. & Halford, G. S. (2001b) Access to relational knowledge: A comparison of two models. In: Proceedings of the Twenty-third Annual Conference of the Cognitive Science Society, Edinburgh, Scotland, 1–4 August 2001, pp. 1142–47, ed. Johanna, D. Moore & Keith, Stenning. Erlbaum.Google Scholar
Young, M. E. & Wasserman, E. A. (1997) Entropy detection by pigeons: Response to mixed visual displays after same-different discrimination training. Journal of Experimental Psychology: Animal Behavior Processes 23:157–70.Google ScholarPubMed
Zelazo, P. D., Jacques, S., Burack, J. A. & Frye, D. (2002) The relation between theory of mind and rule use: Evidence from persons with autism-spectrum disorders. Infant and Child Development 11:171–95.CrossRefGoogle Scholar