Assessing Symmetry by Comparing the Acquisition of Symmetric and Nonsymmetric Conditional Relations in a Capuchin Monkey

  • Paulo S. D. Soares Filho Universidad de San Buenaventura
  • Álvaro J. M. Silva Universidade Federal do Pará
  • Saulo M Velasco Centro Paradigma de Ciências do Comportamento
  • Romariz S Barros Universidade Federal do Pará
  • Gerson Yukio Tomanari Universidade de São Paulo
Keywords: Conditional discrimination, Equivalence class formation, Symmetry, Sapajus spp


The present study presents a procedure to assess the property of symmetry by comparing the acquisition of conditional relations that are consistent and inconsistent with this property in a capuchin monkey (Sapajus spp.). One young male monkey underwent arbitrary matching-to-sample training. The experiment had four phases: Phase 1.1 (establishing A1B1 and A2B2 relations), Phase 1.2 (reinforcing B1A1 and B2A2 relations, consistent with the property of symmetry), Phase 2.1 (establishing A3B3 and A4B4 relations), and Phase 2.2 (reinforcing B3A4 and B4A3 relations, inconsistent with the property of symmetry). A comparison between Phase 1.2 (consistent) and Phase 2.2 (inconsistent) showed faster acquisition of consistent relations (B1A1 and B2A2) than inconsistent relations (B3A4 and B4A3). The results suggest that the established conditional discriminations may have the property of symmetry and confirm the potential of comparative analysis between the acquisition of conditional discriminations as a promising procedure to evaluate equivalence class formation in nonhuman subjects.


Antonitis, J. J. (1951). Response variability in the white rat during conditioning, extinction, and reconditioning. Journal of Experimental Psychology, 42, 273-281. doi: 10.1037/h0060407

Azrin, N. H., Hutchinson, R. R., & Hake, D. F. (1966). Extinction-induced aggression. Journal of the Experimental Analysis of Behavior, 9, 191-204. doi: 10.1901/jeab.1966.9-191

Barros, R. S., Galvão, O. F., & Fontes, J. C. (1996). Um teste de simetria após treino de discriminações condicionais de posição com macaco Ateles paniscus paniscus [A symmetry test after training position conditional discriminations with macacus Ateles paniscus paniscus]. Acta Comportamentalia, 4, 181-204.

Barros, R. S., Galvão, O. F., & McIlvane, W. J. (2002). The search for relational learning capacity in Cebus apella: a programmed “educational” approach. In: S. Soraci, Jr. & K. Murata-Soraci (Eds.), Visual information processing (pp. 223-245). Westport: Praeger.

Brino, A. L., Galvão, O. F., & Barros, R. S. (2009). Successive identity matching to sample tests without reinforcement in Cebus apella. Ciências e Cognição, 14, 2-11. Retrieved from:

D’Amato, M. R., Salmon, D. P., Loukas, E., & Tomie, A. (1985). Symmetry and transitivity of conditional relations in monkeys (Cebus apella) and pigeons (Columbia livia). Journal of the Experimental Analysis of Behavior, 44, 35-47. doi: 10.1901/jeab.1985.44-35

Devany, J. M., Hayes, S. C., & Nelson, R. O. (1986). Equivalence class formation in language-able and language-disabled children. Journal of the Experimental Analysis of Behavior, 46, 243-257. doi: 10.1901/jeab.1986.46-243

Dube, W. V. & McIlvane, W. J. (1996). Some implications of a stimulus control topography analysis for emergent behavior and stimulus classes. In: T. R. Zentall & P. M. Smeets (Eds.), Stimulus class formation in humans and animals (pp. 197-218). Amsterdam: Elsevier.

Dube, W. V., McIlvane, W. J., & Green, G. (1992). An analysis of generalized identity matching-to-sample test procedures. Psychological Record, 42, 17-28.

Dugdale, N. & Lowe, C. F. (2000). Testing for symmetry in conditional discriminations of language-trained chimpanzees. Journal of the Experimental Analysis of Behavior, 73, 5-22. doi: 10.1901/jeab.2000.73-5

Epstein, R. (1983). Resurgence of previously reinforced behavior during extinction. Behaviour Analysis Letters, 3, 391-397.

Epstein, R. (1985). Extinction-induced resurgence: preliminary investigations and possible applications. Psychological Record, 35, 143-153.

Frank, A. J. (2007). An examination of the temporal and spatial stimulus control in emergent symmetry in pigeons. Unpublished doctoral dissertation, University of Iowa. Retrieved from:

Frank, A. J. & Wasserman, E. A. (2005). Associative symmetry in the pigeon after successive matching-to-sample training. Journal of the Experimental Analysis of Behavior, 84, 147-165. doi: 10.1901/jeab.2005.115-04

Galvão, O. F., Calcagno, S., & Sidman, M. (1992). Testing for emergent performance in extinction. Experimental Analysis of Human Behavior Bulletin, 10, 18-20.

Galvão, O. F., Barros, R. S., Santos, J. R., Brino, A. L. F., Brandão, S., Lavratti, C. M., Dube, W. V., & McIlvane, W. J. (2005). Extent and limits of the matching concept in Cebus apella: a matter of experimental control? Psychological Record, 55, 219-232.

Galvão, O. F., Soares Filho, P. S. D., Barros, R. S., & Souza, C. B. A. (2008). Matching-to-sample as a model of symbolic behavior for bio-behavioral investigation. Reviews in the Neurosciences, 19, 149-156.

Gray, L. (1966). Backward association in pigeons. Psychonomic Science, 4, 333-334.

Harlow, H. F. (1949). The formation of learning sets. Psychological Review, 56, 51-65. doi: 10.1037/h0062474

Hayes, S. C. (1989). Nonhumans have not yet shown stimulus equivalence. Journal of the Experimental Analysis of Behavior, 51, 385-392. doi: 10.1901/jeab.1989.51-385

Hayes, S. C., Barnes-Holmes, D., & Roche, B. (2001). Relational frame theory: a post-Skinnerian account of human language and cognition. New York: Plenum.

Hogan, D. E. & Zentall, T. R. (1977). Backward associations in pigeon. American Journal of Psychology, 90, 3-15. doi: 10.2307/1421635

Holmes, P. W. (1979). Transfer of matching performance in pigeons. Journal of the Experimental Analysis of Behavior, 31, 103-114. Doi: 10.1901/jeab.1979.31-103

Huziwara, E. M., Velasco, S. M., Tomanari, G. Y., de Souza, D. G., & Machado, A. (2012). Emergent relations in pigeons following training with temporal samples. Learning and Behavior, 40, 192-204. doi: 10.3758/s13420-012-0097-z

Kastak, D. & Schusterman, R. J. (1994). Transfer of visual identity matching-to-sample in two California sea lions (Zalophus californianus). Animal Learning and Behavior, 22, 427-435. Retrieved from:

Keller, F. S. & Schoenfeld, W. N. (1950). Principles of psychology: a systematic text in the science of behavior. New York: Appleton-Century-Crofts.

Lerman, D. C. & Iwata, B. A. (1996). Developing a technology for the use of operant extinction in clinical settings: an examination of basic and applied research. Journal of Applied Behavior Analysis, 29, 345-382. doi: 10.1901/jaba.1996.29-345

Lionello-DeNolf, K. M. (2009). The search for symmetry: 25 years in review. Learning and Behavior, 37, 188-203. doi: 10.3758/LB.37.2.188.

Lionello-DeNolf, K. M. & Urcuioli, P. J. (2002). Stimulus control topographies and tests of symmetry in pigeons. Journal of the Experimental Analysis of Behavior, 78, 467-495. doi: 10.1901/jeab.2002.78-467

Lipkens, R., Kop, P. F. M., & Matthijs, W. (1988). A test for symmetry and transitivity in the conditional discrimination performances of pigeons. Journal of the Experimental Analysis of Behavior, 49, 395-409. doi: 10.1901/jeab.1988.49-395

McIlvane, W. J., Serna, R. W., Dube, W. V., & Stromer, R. (2000). Stimulus control topography coherence and stimulus equivalence: reconciling test outcomes with theory. In: J. Leslie & D. E. Blackman (Eds.), Experimental and applied analysis of human behavior (pp. 85-110). Reno: Context Press.

Picanço, C. R. & Barros, R. S. (2015). Symmetry evaluation by comparing acquisition of conditional relations in successive (Go/No-Go) matching-to-sample training. Psychological Record, 65, 131-139. Retrieved from:

Schusterman, R. J. & Kastak, D. (1993). A California sea lion (Zalophus californianus) is capable of forming equivalence relations. Psychological Record, 43, 823-839.

Sidman, M. (1994). Equivalence relations and behavior: a research story. Boston: Authors Cooperative.

Sidman, M. (2000). Equivalence relations and the reinforcement contingency. Journal of the Experimental Analysis of Behavior, 74, 127-146. doi: 10.1901/jeab.2000.74-127

Sidman, M. & Cresson, O., Jr. (1973). Reading and crossmodal transfer of stimulus equivalences in severe retardation. American Journal of Mental Deficiency, 77(5), 515-523. Retrieved from:

Sidman, M. & Tailby, W. (1982). Conditional discrimination vs. matching to sample: an expansion of the testing paradigm. Journal of the Experimental Analysis of Behavior, 37, 5-22. doi: 10.1901/jeab.1982.37-5

Sidman, M., Rauzin, R., Lazar, R., Cunningham, S., Tailby, W., & Carrigan, P. (1982). A search for symmetry in the conditional discriminations of rhesus monkeys, baboons, and children. Journal of the Experimental Analysis of Behavior, 37, 23-44. doi: 10.1901/jeab.1982.37-23

Skinner, B. F. (1938). The behavior of organisms: an experimental analysis. New York: Appleton-Century-Crofts.

Sweeney M. M. & Urcuioli, P. J. (2010). Reflexivity in pigeons. Journal of the Experimental Analysis of Behavior, 94, 267-282. doi: 10.1901/jeab.2010.94-267

Urcuioli, P. J. (2008). Associative symmetry, antisymmetry, and a theory of pigeons’ equivalence-class formation. Journal of the Experimental Analysis of Behavior, 90, 257-282. doi: 10.1901/jeab.2008.90-257

Urcuioli, P. J. & Swisher, M. (2012). Emergent identity matching after successive matching training: II. Reflexivity or transitivity? Journal of the Experimental Analysis of Behavior, 97, 5-27. doi: 10.1901/jeab.2012.97-5

Vasconcelos, M. & Urcuioli, P. J. (2011). Associative symmetry in a spatial-response paradigm. Behavioural Processes, 86, 305-315. doi: 10.1016/j.beproc.2011.01.002

Velasco, S. M., Huziwara, E. M., Machado, A., & Tomanari, G. Y. (2010). Associative symmetry by pigeons after few-exemplar training. Journal of the Experimental Analysis of Behavior, 94(3), 283-295. doi: 10.1901/jeab.2010.94-283

Villas-Bôas, A., Murayama, V. K., & Tomanari, G. Y. (2005). Ressurgência: conceitos e métodos que podem (ou não) contribuir para a análise do comportamento. In: H. J. Guilhardi & N. C. Aguirre (Eds.), Sobre comportamento e cognição: Vol. 15. Expondo a variabilidade (pp. 18-28). Santo André: ESETec.

Wilson, K. G. & Hayes, S. C. (1996). Resurgence of derived stimulus relations. Journal of the Experimental Analysis of Behavior, 66, 267-281.doi: 10.1901/jeab.1996.66-267

Yamamoto, J. & Asano, T. (1995). Stimulus equivalence in a chimpanzee (Pan troglodytes). Psychological Record, 45, 3-21.