Journal of Ornithology

, Volume 148, Supplement 2, pp 161–168 | Cite as

Individual differences in grey parrots (Psittacus erithacus): effects of training

  • Irene M. PepperbergEmail author


Grey parrots (Psittacus erithacus) have been shown to exhibit many complex cognitive and communicative abilities in a laboratory setting. The parrots’ successes likely rely on two factors: An underlying neurological architecture that supports complex information processing, and training that enables them to express their capacities in ways measurable by human researchers. Individual differences likely can affect both factors, in terms of biology for the former and in response to the quality of the latter, but the quality of the latter can be experimentally controlled. Although training my parrots to communicate in English speech generally enables me to demonstrate their advanced cognitive capacities, occasionally such training has interfered with success on tasks requiring a specific type of complex information processing. For two cohorts of parrots, one with and one without extensive communicative training, I describe here the results for two different tasks. In one task—the ability to segment English speech sounds and demonstrate phonological awareness—communication training, as expected, enhanced success [IM Pepperberg (2007) Lang Sci 29:1–13]. In the other task—retrieval of an item suspended from a long string to demonstrate means–ends understanding—communication training unexpectedly inhibited success [IM Pepperberg (2004) Anim Cogn 7:263–266]. Individual differences can therefore be expressed in ways that are not necessarily predictable and that encourage further experimentation.


Grey parrots Individual differences Insight Phonological awareness 



I thank Drs. Diana Reiss (Wildlife Conservation Society, NYC) and Donald Kroodsma (University of Massachusetts–Amherst) for creating the sonagrams on Raven, Dr. Ofer Tchernichovski (CCNY) for the sonagram using Sound Analysis Pro, and Dr. Diane Patterson for alerting me to the issue of “filler” phonemes. Research was supported by donors to The Alex Foundation, most notably the American Foundation, the Pearl Family Foundation, the Eleanor Lloyd Dees Foundation, and the South Bay Bird Society. I thank Terry Clyne of Apalachee River Aviary for donating Griffin, Madonna LaPell of VIP Aviaries for donating Kyaaro, and Kim Gaudette for handraising Arthur. The experiments comply with all laws governing research in the United States.


  1. Anthony JL, Francis D (2005) Development of phonological awareness. Curr Dir Psychol Sci 14:255–259CrossRefGoogle Scholar
  2. Byrne RW (1995) Primate cognition: comparing problems and skills. Am J Primatol 37:127-141CrossRefGoogle Scholar
  3. Carere C, Eens M (2005) Unravelling animal personalities: how and why individuals consistently differ. Behaviour 142:1149–1157CrossRefGoogle Scholar
  4. Case R (1984) Intellectual development: birth to adulthood. Academic, OrlandoGoogle Scholar
  5. Chaiken ML, Gentner TQ, Hulse SH (1997) Effects of social interaction on the development of starling song and the perception of these effects by conspecifics. J Comp Psychol 111:379–392PubMedCrossRefGoogle Scholar
  6. Gómez JC (1990) The emergence of intentional communication as a problem-solving strategy in the gorilla. In: Parker ST, Gibson KR (eds) “Language” and intelligence in monkeys and apes: comparative developmental perspectives. Cambridge University, New York, pp 333-355Google Scholar
  7. Greenfield PM (1991) Language, tools and brain: the ontogeny and phylogeny of hierarchically organized sequential behavior. Behav Brain Sci 14:531-595Google Scholar
  8. DeVoogd TJ (2004) Neural constraints on the complexity of avian song. Brain Behav Evol 63:221–232PubMedCrossRefGoogle Scholar
  9. Heinrich B (1995) An experimental investigation of insight in common Ravens (Corvus corax). Auk 112:994-1003Google Scholar
  10. Heinrich B, Bugnyar T (2005) Testing problem solving in ravens: string-pulling to reach food. Ethology 111:962–976CrossRefGoogle Scholar
  11. Jarvis ED, Güntürkün O, Bruce L, Csillag A et al. (2005) Avian brains and a new understanding of vertebrate brain evolution. Nat Rev Neurosci 6:151–159PubMedCrossRefGoogle Scholar
  12. Kemmerer D (1996) What about the increasing adaptive value of manipulative language use? Behav Brain Sci 19:546-548CrossRefGoogle Scholar
  13. Leonard LB (2001) Fillers across languages and language abilities. J Child Lang 28:257–261PubMedCrossRefGoogle Scholar
  14. Lieberman P (1984) The biology and evolution of language. Harvard, CambridgeGoogle Scholar
  15. Moore B (1992) Avian movement imitation and a new form of mimicry: tracing the evolution of a complex form of learning. Behaviour 122:231–263CrossRefGoogle Scholar
  16. Patterson DK, Pepperberg IM (1994) A comparative study of human and parrot phonation: acoustic and articulatory correlates of vowels. J Acoust Soc Am 96:634–648PubMedCrossRefGoogle Scholar
  17. Patterson DK, Pepperberg IM (1998) Acoustic and articulatory correlates of stop consonants in a parrot and a human subject. J Acoust Soc Am 103:2197–2215PubMedCrossRefGoogle Scholar
  18. Pepperberg IM (1981) Functional vocalizations by an African Grey parrot (Psittacus erithacus). Z Tierpsychol 55:139–160Google Scholar
  19. Pepperberg IM (1994) Vocal learning in African Grey parrots: effects of social interaction. Auk 111:300–313Google Scholar
  20. Pepperberg IM (1999) The Alex studies. Harvard, CambridgeGoogle Scholar
  21. Pepperberg IM (2004) “Insightful” string-pulling in Grey parrots (Psittacus erithacus) is affected by vocal competence. Anim Cogn 7:263–266PubMedCrossRefGoogle Scholar
  22. Pepperberg IM (2006a) Grey parrot (Psittacus erithacus) numerical abilities: addition and further experiments on a zero-like concept. J Comp Psychol 120:1–11PubMedCrossRefGoogle Scholar
  23. Pepperberg IM (2006b) Ordinality and inferential abilities of a Grey parrot (Psittacus erithacus). J Comp Psychol 120:205–216PubMedCrossRefGoogle Scholar
  24. Pepperberg IM (2007a) Grey parrots do not always “parrot”: roles of imitation and phonological awareness in the creation of new labels from existing vocalizations. Lang Sci 29:1–13CrossRefGoogle Scholar
  25. Pepperberg IM (2007b) When training engenders a failure to imitate in Grey parrots (Psittacus erithacus). In: Lopes M (ed) Proceedings of the AISB’07 4th international symposium on imitation in animals and artifacts, University of Newcastle, Newcastle, pp 38–42Google Scholar
  26. Pepperberg IM, Gordon JD (2005) Numerical comprehension by a Grey parrot (Psittacus erithacus), including a zero-like concept. J Comp Psychol 119:197–209PubMedCrossRefGoogle Scholar
  27. Pepperberg IM, Shive H (2001) Simultaneous development of vocal and physical object combinations by a Grey parrot (Psittacus erithacus): bottle caps, lids, and labels. J Comp Psychol 115:376–384PubMedCrossRefGoogle Scholar
  28. Pepperberg IM, Wilcox SE (2000) Evidence for a form of mutual exclusivity during label acquisition by Grey parrots (Psittacus erithacus)? J Comp Psych 114:219–231CrossRefGoogle Scholar
  29. Pepperberg IM, Wilkes SR (2004) Lack of referential vocal learning from LCD video by Grey parrots (Psittacus erithacus). Interact Stud 5:75–97CrossRefGoogle Scholar
  30. Pepperberg IM, Brese KJ, Harris BJ (1991) Solitary sound play during acquisition of English vocalizations by an African Grey parrot (Psittacus erithacus): possible parallels with children’s monologue speech. Appl Psycholing 12:151–177CrossRefGoogle Scholar
  31. Pepperberg IM, Garcia SE, Jackson EC, Marconi S (1995) Mirror use by African Grey parrots (Psittacus erithacus). J Comp Psychol 109:182–195CrossRefGoogle Scholar
  32. Pepperberg IM, Gardiner LI, Luttrell LJ (1999) Limited contextual vocal learning in the Grey parrot (Psittacus erithacus): the effect of co-viewers on videotaped instruction. J Comp Psychol 113:158–172CrossRefGoogle Scholar
  33. Pepperberg IM, Willner MR, Gravitz LB (1997) Development of Piagetian object permanence in a Grey parrot (Psittacus erithacus). J Comp Psychol 111:63–75PubMedCrossRefGoogle Scholar
  34. Peters AN (2001) Filler syllables: what is their status in emerging grammar? J Child Lang 28:229–242PubMedCrossRefGoogle Scholar
  35. Port RF (2007) How are words stored in memory? Beyond phones and phonemes. New Ideas Psychol 25 (in press)Google Scholar
  36. Port RF, Leary AP (2005) Against formal phonology. Language 81:927–964CrossRefGoogle Scholar
  37. Rakic P, Bourgeois J-P, Zecevic N, Eckenhoff MF, Goldman-Rakic PS (1986) Concurrent overproduction in synapses in diverse regions of the primate cerebral cortex. Science 232:232–235PubMedCrossRefGoogle Scholar
  38. Rozin P (1976) The evolution of intelligence and access to the cognitive unconscious. In: Sprague JM, Epstein AN (eds) Progress in psychobiology and physiological psychology, vol. 6. Academic, New York, pp 245–280Google Scholar
  39. Seligman ME, Maier SF (1967) Failure to escape traumatic shock. J Exp Psychol 74:1–9PubMedCrossRefGoogle Scholar
  40. Stamps JA (2003) Behavioural processes affecting development: Tinbergen’s fourth question comes of age. Anim Behav 66:1–13CrossRefGoogle Scholar
  41. Todt D (1975) Social learning of vocal patterns and modes of their applications in Grey parrots. Z Tierpsychol 39:178–188Google Scholar
  42. Visalberghi E (1997) Success and understanding in cognitive tasks: a comparison between Cebus apella and Pan troglodytes. Int J Primatol 18:811–830CrossRefGoogle Scholar
  43. Warren DK, Patterson DK, Pepperberg IM (1996) Mechanisms of American English vowel production in a Grey parrot (Psittacus erithacus). Auk 113:41–58Google Scholar

Copyright information

© Dt. Ornithologen-Gesellschaft e.V. 2007

Authors and Affiliations

  1. 1.Department of PsychologyHarvard UniversityCambridgeUSA
  2. 2.Department of PsychologyBrandeis UniversityWalthamUSA

Personalised recommendations