Capuchin monkeys have been tested for the capacity to delay gratification for accumulating rewards in recent studies and have exhibited variable results. Meanwhile, chimpanzees have consistently excelled at this task. However, neither species have ever been tested at accumulating symbolic tokens instead of food items, even though previous reports indicate that tokens sometimes facilitate performance in other self-control tasks. Thus, in the present study, we tested capuchin monkeys and chimpanzees for their capacity to delay gratification in a delay maintenance task, in which an experimenter presented items, one at a time, to within reach of an animal for as long as the animal refrained from taking them. In Experiment 1, we assessed how long capuchin monkeys could accumulate items in the delay maintenance task when items were food rewards or tokens exchangeable for food rewards. Monkeys accumulated more food rewards than they did tokens. In Experiment 2, we tested capuchin monkeys and chimpanzees in a similar accumulation test. Whereas capuchins again accumulated more food than tokens, all chimpanzees but one showed no difference in performance in the two conditions. These findings provide additional evidence that chimpanzees exhibit greater self-control capacity in this task than do capuchin monkeys and indicate that symbolic stimuli fail to facilitate delay maintenance when they do not abstract away from the quantitative dimension of the task. This is consistent with previous findings on the effects of symbols on self-control and illuminates what makes accumulation a particularly challenging task.
This is a preview of subscription content, access via your institution.
Buy single article
Instant access to the full article PDF.
Tax calculation will be finalised during checkout.
Subscribe to journal
Immediate online access to all issues from 2019. Subscription will auto renew annually.
Tax calculation will be finalised during checkout.
Of particular interest were two food accumulation trials with the chimpanzees (one trial each with Sherman and Panzee) in which the experimenter accidentally missed the accumulation bowl and the food item landed on the floor. In both cases, the chimpanzee picked up the food item, but did not eat it, and instead, immediately placed the item into the accumulation bowl. The experimenter continued the trial as usual.
Addessi E, Rossi S (2011) Tokens improve capuchin performance in the reverse–reward contingency task. Proc R Soc B Biol Sci 278:849–854. doi:10.1098/rspb.2010.1602
Addessi E, Paglieri F, Focaroli V (2011) The ecological rationality of delay tolerance: insights from capuchin monkeys. Cognition 119:142–147
Anderson JR, Kuroshima H, Fujita K (2010) Delay of gratification in capuchin monkeys (Cebus apella) and squirrel monkeys (Saimiri sciureus). J Comp Psychol 124:205–210. doi:10.1037/a0018240
Baumeister RF, Vohs KD (eds) (2004) Handbook of self-regulation: research theory and applications. Guilford Press, New York
Beran MJ (2002) Maintenance of self-imposed delay of gratification by four chimpanzees (Pan troglodytes) and an orangutan (Pongo pygmaeus). J Gen Psychol 129:49–66. doi:10.1080/00221300209602032
Beran MJ, Evans TA (2006) Maintenance of delay of gratification by four chimpanzees (Pan troglodytes): the effects of delayed reward visibility, experimenter presence, and extended delay intervals. Behav Process 73:315–324. doi:10.1016/j.beproc.2006.07.005
Beran MJ, Evans TA (2009) Delay of gratification by chimpanzees (Pan troglodytes) in working and waiting situations. Behav Process 80:177–181. doi:10.1016/j.beproc.2008.11.008
Beran MJ, Savage-Rumbaugh ES, Pate JL, Rumbaugh DM (1999) Delay of gratification in chimpanzees (Pan troglodytes). Dev Psychobiol 34:119–127. doi:10.1002/(SICI)1098-2302(199903)34:2<119:AID-DEV5>3.0.CO;2-P
Beran MJ, Harris EH, Evans TA, Klein ED, Chan B, Flemming TM, Washburn DA (2008) Ordinal judgments of symbolic stimuli by capuchin monkeys (Cebus apella) and rhesus monkeys (Macaca mulatta): the effects of differential and nondifferential reward. J Comp Psychol 122:52–61
Beran MJ, Evans TA, Hoyle D (2011) Numerical judgments by chimpanzees (Pan troglodytes) in a token economy. J Exp Psychol Anim Behav Process 37:165–174. doi:10.1037/a0021472
Boysen ST (2006) The impact of symbolic representations on chimpanzee cognition. In: Hurley S, Nudds M (eds) Rational animals?. Oxford University Press, New York, pp 489–511
Boysen ST, Bernston GG (1995) Responses to quantity: perceptual versus cognitive mechanisms in chimpanzees. J Exp Psychol Anim Behav Process 21:82–86
Boysen ST, Mukobi KL, Bernston GG (1999) Overcoming response bias using symbolic representations of number by chimpanzees (Pan troglodytes). Animal Learn Behav 27:229–235
Brosnan SF, de Waal FBM (2003) Monkeys reject unequal pay. Nature 425:297–299
Brosnan SF, de Waal FBM (2004a) A concept of value during experimental exchange in brown capuchin monkeys, Cebus apella. Folia Primatol 75:317–330. doi:10.1159/000080209
Brosnan SF, de Waal FBM (2004b) Socially learned preferences for differentially rewarded tokens in the brown capuchin monkey (Cebus apella). J Comp Psychol 118:133–139
Brosnan S, de Waal F (2009) Cebus apella tolerate intermittent unreliability in human experimenters. Int J Primatol 30(5):663–674. doi:10.1007/s10764-009-9366-x
Brosnan SF, Parrish A, Beran MJ, Flemming T, Heimbauer L, Talbot CF, Lambeth SP, Schapiro SJ, Wilson BJ (2011) Responses to the assurance game in monkeys, apes, and humans using equivalent procedures. Proc Nat Acad Sci 108:3442–3447. doi:10.1073/pnas.1016269108
Chelonis JJ, King G, Logue AW, Tobin H (1994) The effect of variable delays on self-control. J Exp Anal Behav 62:33–43. doi:10.1901/jeab.1994.62-33
Cheng K, Peña J, Porter M, Irwin J (2002) Self-control in honeybees. Psychon Bull Rev 9:259–263. doi:10.3758/bf03196280
Evans TA, Beran MJ (2007a) Chimpanzees use self-distraction to cope with impulsivity. Biol Lett 3:599–602. doi:10.1098/rsbl.2007.0399
Evans TA, Beran MJ (2007b) Delay of gratification and delay maintenance in rhesus macaques (Macaca mulatta). J Gen Psychol 134:199–216
Green L, Estle SJ (2003) Preference reversals with food and water reinforcers in rats. J Exp Anal Behav 79:233–242
Green L, Fry AF, Myerson J (1994) Discounting of delayed rewards: a life-span comparison. Psychol Sci 5:33–36. doi:10.1111/j.1467-9280.1994.tb00610.x
Grosch J, Neuringer A (1981) Self-control in pigeons under the Mischel paradigm. J Exp Anal Behav 35:3–21. doi:10.1901/jeab.1981.35-3
Hopper LM, Essler J, Freeman H, Talbot CF, Lambeth SP, Schapiro SJ, Williams LE, Brosnan SF (in prep) Enough is enough: the effect of the frequency of unequal outcomes on decisions to accept food rewards in four primate species
Killeen PR, Smith JP, Hanson SJ (1981) Central place foraging in Rattus norvegicus. Anim Behav 29:64–70. doi:10.1016/s0003-3472(81)80152-2
Lawyer SR, Williams SA, Prihodova T, Rollins JD, Lester AC (2010) Probability and delay discounting of hypothetical sexual outcomes. Behav Process 84:687–692. doi:10.1016/j.beproc.2010.04.002
Logue AW (1988) Research on self-control: an integrating framework. Behav Brain Sci 11:665–709. doi:10.1017/S0140525X00053978
Logue AW, Pena-Correal TE (1985) The effect of food deprivation on self-control. Behav Process 10:355–368
Logue AW, Forzano LB, Ackerman KT (1996) Self-control in children: age, preference for reinforcer amount and delay, and language ability. Learn Motiv 27:260–277. doi:10.1006/lmot.1996.0014
Mazur JE (2007) Species differences between rats and pigeons in choices with probabilistic and delayed reinforcers. Behav Process 75:220–224
Mischel W (1974) Processes in delay of gratification. Adv Exp Soc Psychol 7:249–292. doi:10.1016/S0065-2601(08)60039-8
Mischel W, Shoda Y, Rodriguez ML (1989) Delay of gratification in children. Science 244:933–938
Mundry R, Fischer J (1998) Use of statistical programs for nonparametric tests of small samples often leads to incorrect P values: examples from animal behaviour. Anim Behav 56:256–259
Parrish A, Brosnan SF (in prep) Changing the relative difference in outcomes affects reactions to unequal rewards in capuchin monkeys (Cebus apella)
Pelé M, Micheletta J, Uhlrich P, Thierry B, Dufour V (2011) Delay maintenance in tonkean macaques (Macaca tonkean) and brown capuchin monkeys (Cebus apella). Int J Primatol 32:149–166. doi:10.1007/s10764-010-9446-y
Stevens JR, Hallinan EV, Hauser MD (2005) The ecology and evolution of patience in two new world monkeys. Biol Lett 1:223–226. doi:10.1098/rsbl.2004.0285
Stevens JR, Rosati AG, Heilbronner SR, Mühlhoff N (2011) Waiting for grapes: expectancy and delayed gratification in bonobos. Int J Comp Psychol 24:99–111
Tobin H, Chelonis JJ, Logue AW (1993) Choice in self-control paradigms using rats. Psychol Rec 43:441–453
Tobin H, Logue AW, Chelonis JJ, Ackerman KT, May JGI (1996) Self-control in the monkey Macaca Fascicularis. Animal Learn Behav 24:168–174
Toner IJ, Smith RA (1977) Age and overt verbalization in delay-maintenance behavior in children. J Exp Child Psychol 24:123–128. doi:10.1016/0022-0965(77)90025-X
van Haaren F, van Hest A, van de Poll NE (1988) Self-control in male and female rats. J Exp Anal Behav 49:201–211. doi:10.1901/jeab.1988.49-201
van Wolkenten M, Brosnan SF, de Waal FBM (2007) Inequity responses of monkeys modified by effort. Proc Nat Acad Sci 104:18854–18859. doi:10.1073/pnas.0707182104
Vick S-J, Bovet D, Anderson J (2010) How do African grey parrots (Psittacus erithacus) perform on a delay of gratification task? Animal Cognit 13:351–358. doi:10.1007/s10071-009-0284-2
Vlamings PHJM, Uher J, Call J (2006) How the great apes (Pan troglodytes, Pongo pygmaeus, Pan paniscus, and Gorilla gorilla) perform on the reversed contingency task: the effects of food quantity and food visibility. J Exp Psychol Anim Behav Process 32:60–70. doi:10.1037/0097-7403.32.1.60
We thank Betty Chan, Daniel Hoyle, and Joseph McIntyre for their assistance with data collection. This research was funded by grants HD-38051 and HD-060563 from the National Institute of Child Health and Human Development and grant BCS-0924811 from the National Science Foundation.
About this article
Cite this article
Evans, T.A., Beran, M.J., Paglieri, F. et al. Delaying gratification for food and tokens in capuchin monkeys (Cebus apella) and chimpanzees (Pan troglodytes): when quantity is salient, symbolic stimuli do not improve performance. Anim Cogn 15, 539–548 (2012). https://doi.org/10.1007/s10071-012-0482-1
- Delay of gratification
- Symbolic stimuli
- Cebus apella
- Pan troglodytes
- Token exchange