Although nonhuman primates have been used in biomedical research to develop a better understanding of physiological aging processes, their value as models for studying age-related differences in motivation, cognition, and decision-making has only recently been appreciated. This paper reviews the state of the art, with a focus on a recent study on Barbary macaques. A number of studies reported that with increasing age, Old World monkeys spend more time resting, have fewer social partners, and/or spend less time in social interactions, though other studies found no such effects. Less was known about changes in cognitive performance and shifts in interest in the physical and social environment across age. A recent comprehensive study of motivational changes in a large age-heterogeneous population of Barbary macaques (Macaca sylvanus) living at “La Forêt des Singes” in Rocamadour explicitly tested predictions from social selectivity theory, which posits that in light of a shrinking future time perspective, humans become increasingly selective in terms of their social interactions. Given that nonhuman primates most likely have no conception of their limited lifetime, this allowed disentangling the effects of cognitive insights and basal physiological processes that contribute to changes in the valuation of different activities. The Barbary macaques under study revealed marked and differential motivational shifts with age: while they interacted with fewer social partners, they continued to attend to social information. In contrast, they revealed a marked loss of interest in novel objects in early adulthood, unless these were baited with a food reward. Some of the motivational changes observed during human aging may thus be shared with our closest living relatives. The awareness of a limited future time perspective in humans may enhance the effects of these ancestral processes, but it does not appear to be the only explanation. Future studies should employ a broader array of different cognitive tests to delineate the trajectories of different cognitive processes such as attention, memory, and behavioral flexibility more clearly. Taken together, an evolutionary developmental psychology perspective that combines life span psychology with evolutionary biology appears to be a promising avenue for investigations of age-related changes in motivation and cognition.

Alwin DF, Hofer SM: Health and cognition in aging research. J Gerontol B Psychol Sci Soc Sci 2011;66(suppl 1):i9-i16.
Roth GS, Mattison JA, Ottinger MA, Chachich ME, Lane MA, Ingram DK: Aging in rhesus monkeys: relevance to human health interventions. Science 2004;305:1423-1426.
Verdier JM, Acquatella I, Lautier C, Devau G, Trouche S, Lasbleiz C, Mestre-Francés N: Lessons from the analysis of nonhuman primates for understanding human aging and neurodegenerative diseases. Front Neurosci 2015; 9:64.
Didier ES, MacLean AG, Mohan M, Didier PJ, Lackner AA, Kuroda MJ: Contributions of nonhuman primates to research on aging. Vet Pathol 2016;53:277-290.
Freund AM, Nikitin J, Riediger M: Successful aging; in Lerner RM, Easterbrooks MA, Mistry J (eds): Handbook of Psychology. Developmental Psychology, ed 2. New York, Wiley, 2012, vol 6, pp 615-638.
Rowe JW, Kahn RL: Human aging: usual and successful. Science 1987;237:143-149.
Almeling L, Hammerschmidt K, Sennhenn-Reulen H, Freund AM, Fischer J: Motivational shifts in aging monkeys and the origins of social selectivity. Curr Biol 2016;26:1744-1749.
Fischer J: Monkeytalk: Inside the Worlds and Minds of Primates. Chicago, University of Chicago Press, 2017.
Colman RJ, Beasley TM, Kemnitz JW, Johnson SC, Weindruch R, Anderson RM: Caloric restriction reduces age-related and all-cause mortality in rhesus monkeys. Nat Commun 2014;5:3557.
Colman RJ, Anderson RM: Nonhuman primate calorie restriction. Antioxid Redox Signal 2011;14:229-239.
Mattison JA, Colman RJ, Beasley TM, Allison DB, Kemnitz JW, Roth GS, Ingram DK, Weindruch R, de Cabo R, Anderson RM: Caloric restriction improves health and survival of rhesus monkeys. Nat Commun 2017;8:14063.
Corr J: Social behavior in aged rhesus macaques. Coll Antropol 2003;27:87-94.
Nakamichi M: Behavioral characteristics of old female Japanese monkeys in a free-ranging group. Primates 1984;25:192-203.
McDonald Pavelka MS: The nonhuman primate perspective: old age, kinship and social partners in a monkey society. J Cross Cult Gerontol 1994;9:219-229.
Veenema HC, Spruijt BM, Gispen WH, Van Hooff JARAM: Aging, dominance history, and social behavior in Java-monkeys (Macaca fascicularis). Neurobiol Aging 1997;18:509-515.
Kato E: Effects of age, dominance, and seasonal changes on proximity relationships in female Japanese macaques (Macaca fuscata) in a free-ranging group at Katsuyama. Primates 1999;40:291-300.
Seyfarth RM: A model of social grooming among adult female monkeys. J Theor Biol 1977;65:671-698.
McDonald Pavelka MS: Sociability in old female Japanese monkeys: human versus nonhuman primate aging. Am Anthropol 1991;93:588-598.
Charles ST, Carstensen LL: Social and emotional aging. Annu Rev Psychol 2010;61:383-409.
Cornwell EY, Waite LJ: Social disconnectedness, perceived isolation, and health among older adults. J Health Soc Behav 2009;50:31-48.
Steptoe A, Shankar A, Demakakos P, Wardle J: Social isolation, loneliness, and all-cause mortality in older men and women. Proc Natl Acad Sci USA 2013;110:5797-5801.
Cumming E, Henry W: Growing Old: The Process of Disengagement. New York, Basic Books, 1961.
Havighurst RJ: Successful aging. Gerontologist 1961;1:8-13.
Tarou LR, Bloomsmith MA, Hoff MP, Erwin JM, Maple TL: The behavior of aged great apes; in Erwin JM, Hof PR (eds): Aging in Nonhuman Primates. Interdisciplinary Topics in Gerontology. Basel, Karger, 2002, vol 31, pp 209-231.
Carstensen LL: Motivation for social contact across the life span: a theory of socioemotional selectivity; in Jacobs JE, Ryan RM (eds): Developmental Perspectives on Motivation: Nebraska Symposium on Motivation, 1992. Lincoln, University of Nebraska Press, 1993, pp 209-254.
Carstensen LL, Isaacowitz DM, Charles ST: Taking time seriously. A theory of socioemotional selectivity. Am Psychol 1999;54:165-181.
Freund AM, Baltes PB: The orchestration of selection, optimization and compensation: an action-theoretical conceptualization of a theory of developmental regulation; in Perrig WJ, Grob A (eds): Control of Human Behavior, Mental Processes, and Consciousness: Essays in Honor of the 60th Birthday of August Flammer. Mahwah/London, Lawrence Erlbaum, 2000, pp 35-58.
Freund AM, Li KZH, Baltes PB: Successful development and aging - the role of selection, optimization, and compensation; in Brandtstädter J, Lerner RM (eds): Action and Self-Development: Theory and Research through the Life Span. Thousand Oaks, Sage Publications, 1997, pp 401-434.
Turckheim GD, Merz E: Breeding Barbary macaques in outdoor open enclosures; in Fa JE (ed): The Barbary Macaque: A Case Study in Conservation. New York/London, Plenum Press, 1984, pp 241-261.
Schell A, Rieck K, Schell K, Hammerschmidt K, Fischer J: Adult but not juvenile Barbary macaques spontaneously recognize group members from pictures. Anim Cogn 2011;14:503-509.
Henkel S, Heistermann M, Fischer J: Infants as costly social tools in male Barbary macaque networks. Anim Behav 2010;79:1199-1204.
Fischer J, Noser R, Hammerschmidt K: Bioacoustic field research: a primer to acoustic analyses and playback experiments with primates. Am J Primatol 2013;75:643-663.
Fischer J, Hammerschmidt K: An overview of the Barbary macaque, Macaca sylvanus, vocal repertoire. Folia Primatol (Basel) 2002;73: 32-45.
Brumm H, Kipper S, Riechelmann C, Todt D: Do Barbary macaques “comment” on what they see? A first report on vocalizations accompanying interactions of third parties. Primates 2005;46:141-144.
Mather M, Carstensen LL: Aging and motivated cognition: the positivity effect in attention and memory. Trends Cogn Sci 2005;9:496-502.
Murphy NA, Isaacowitz DM: Preferences for emotional information in older and younger adults: a meta-analysis of memory and attention tasks. Psychol Aging 2008;23:263-286.
Rosati AG, Santos LR: Changes in social cognition and decision-making across the lifespan in semi-free ranging rhesus monkeys (talk). Joint Meeting of the International Primatological Society and American Primatological Society 2016.
Depping MK, Freund AM: When choice matters: task-dependent memory effects in older adulthood. Psychol Aging 2013;28:923-936.
Bethell EJ, Holmes A, MacLarnon A, Semple S: Evidence that emotion mediates social attention in rhesus macaques. PLoS One 2012;7:e44387.
Silk JB: The adaptive value of sociality in mammalian groups. Philos Trans R Soc B Biol Sci 2007;362:539-559.
Silk JB, Beehner JC, Bergman TJ, Crockford C, Engh AL, Moscovice LR, Wittig RM, Seyfarth RM, Cheney DL: Strong and consistent social bonds enhance the longevity of female baboons. Curr Biol 2010;20:1359-1361.
Schülke O, Bhagavatula J, Vigilant L, Ostner J: Social bonds enhance reproductive success in male macaques. Curr Biol 2010;20:2207-2210.
Noë R, Hammerstein P: Biological markets: supply and demand determine the effect of partner choice in cooperation, mutualism and mating. Behav Ecol Sociobiol 1994;35:1-11.
Fredrickson BL, Carstensen LL: Choosing social partners - how old age and anticipated endings make people more selective. Psychol Aging 1990;5:335-347.
Ostner J, Schülke O: The evolution of social bonds in primate males. Behaviour 2014;151:871-906.
Moscovice LR, Di Fiore A, Crockford C, Kitchen DM, Wittig RM, Seyfarth RM, Cheney DL: Hedging their bets? Male and female chacma baboons form friendships based on likelihood of paternity. Anim Behav 2010;79:1007-1015.
Fischer J, Kopp GH, Dal Pesco F, Goffe AS, Hammerschmidt K, Kalbitzer U, Klapproth M, Maciej P, Ndao I, Patzelt A, Zinner D: Charting the neglected West: the social system of Guinea baboons. Am J Phys Anthropol 2017;162(suppl 63):15-31.
Kalbitzer U, Heistermann M, Cheney DL, Seyfarth RM, Fischer J: Social behavior and patterns of testosterone and glucocorticoid levels differ between male chacma and Guinea baboons. Horm Behav 2015;75:100-110.
Hodges JK, Heistermann M: Field endocrinology: monitoring hormonal changes in free-ranging primates; in Setchell JM, Curtis DJ (eds): Field and Laboratory Methods in Primatology, ed 2. Cambridge, Cambridge University Press, 2011, pp 353-370.
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.