Title: Children's Help and the Pace of Reproduction: Cooperative Breeding in Humans
Abstract: Evolutionary Anthropology: Issues, News, and ReviewsVolume 14, Issue 6 p. 224-237 Articles Children's Help and the Pace of Reproduction: Cooperative Breeding in Humans Karen L. Kramer, Karen L. Kramer Karen Kramer is an assistant professor of anthropology at Stony Brook University. Her recently published book on cooperative breeding presents an analysis of Maya family economics and reproductive decisions. She is currently working with South American foragers and horticulturalists as a comparative sample for the effects of economic transition on reproductive outcomesSearch for more papers by this author Karen L. Kramer, Karen L. Kramer Karen Kramer is an assistant professor of anthropology at Stony Brook University. Her recently published book on cooperative breeding presents an analysis of Maya family economics and reproductive decisions. She is currently working with South American foragers and horticulturalists as a comparative sample for the effects of economic transition on reproductive outcomesSearch for more papers by this author First published: 16 December 2005 https://doi.org/10.1002/evan.20082Citations: 205 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat Abstract Because children's ability to support themselves falls below their consumption, human young are subsidized by others throughout much of their growth and development. Mothers, however, who often have multiple dependents of different ages, are faced with an allocation problem (Fig. 1). This has led to important debate about the evolution of a long period dependence and the development of nonmaternal strategies to provision young. This article focuses on the critical role that children themselves play. Because the human subsistence niche incorporates a broad diversity of resources that require variable procurement and processing costs, dependent children can also be important producers, furthering both a need and an opportunity for cooperative breeding. REFERENCES 1 Brown JL. 1987. Helping and communal breeding in birds. Princeton: Princeton University Press. 10.1515/9781400858569 Google Scholar 2 Altmann J. 1980. Baboon mothers and infants. Cambridge: Harvard University Press. Google Scholar 3 Nicolson NA. 1987. Infants, mothers, and other females. In: BB Smuts, DL Cheney, RM Seyfarth, RW Wrangham, TT Struhsaker, editors. Primate societies. Chicago: University of Chicago Press. p 330–342. Google Scholar 4 Lancaster J, Lancaster C. 1987. The watershed: change in parental-investment and family-formation strategies in the course of human evolution. In: J Lancaster, J Altmann, A Rossi, L Sherrod, editors. Parenting across the life span. New York: Aldine De Gruyter. p 187–205. Google Scholar 5 Kaplan H. 1996. A theory of fertility and parental investment in traditional and modern human societies. Yearbook Phys Anthropol 39: 91–135. 10.1002/(SICI)1096-8644(1996)23+<91::AID-AJPA4>3.0.CO;2-C Web of Science®Google Scholar 6 Bogin B. 1999. Patterns of human growth. Cambridge: Cambridge University Press. Google Scholar 7 Hames R. 1988. The allocation of parental care among the Ye'Kawana. In: L Betzig, M Borgerhoff Mulder, P Turke, editors. Human reproductive behavior. Cambridge: Cambridge University Press. p 237–251. Google Scholar 8 Hewlett B. 1991. Demography and childcare in preindustrial societies. J Anthropol Res 47: 1–37. 10.1086/jar.47.1.3630579 CASPubMedWeb of Science®Google Scholar 9 Hill K, Hurtado M. 1996. Ache life history. New York: Aldine de Gruyter. Google Scholar 10 Hrdy SB. 1999. Mother nature. New York: Pantheon Books. Google Scholar 11 Lancaster J. 1991. A feminist and evolutionary biologist looks at women. Yearbook Phys Anthropol 34: 1–11. 10.1002/ajpa.1330340603 Web of Science®Google Scholar 12 Lee RB. 1979. The !Kung San: men, women and work in a foraging society. Cambridge: Cambridge University Press. Google Scholar 13 Panter-Brick C. 1989. Motherhood and subsistence work: the Tamang of rural Nepal. J Biosoc Sci 23: 137–154. Google Scholar 14 Alvarez HP. 2000. Grandmother hypothesis and primate life histories. Am J Phys Anthropol 113: 435–450. 10.1002/1096-8644(200011)113:3<435::AID-AJPA11>3.0.CO;2-O CASPubMedWeb of Science®Google Scholar 15 Hawkes K, O'Connell J, Blurton Jones N. 1989. Hardworking Hadza grandmothers. In: V Standen, RA Foley, editors. Comparative socioecology: the behavioral ecology of humans and other mammals. London: Basil Blackwell Press. p 341–366. Google Scholar 16 Hawkes K, O'Connell J, Blurton Jones N. 1997. Hadza women's time allocation, offspring provisioning and the evolution of long postmenopausal life spans. Curr Anthropol 38: 551–577. 10.1086/204646 Web of Science®Google Scholar 17 O'Connell JF, Hawkes K, Blurton Jones NG. 1999. Grandmothering and the evolution of Homo erectus. J Hum Evol 36: 461–485. 10.1006/jhev.1998.0285 CASPubMedWeb of Science®Google Scholar 18 Hurtado M, Hawkes K, Hill K, Kaplan H. 1992. Trade-offs between female food acquisition and child care among Hiwi and Ache foragers. Hum Nat 3: 1–28. 10.1007/BF02692239 PubMedGoogle Scholar 19 Irons W. 1983. Human female reproductive strategies. In: S Wasser, editor. Social behavior of female vertebrates. New York: Academic Press. p 169–213. 10.1016/B978-0-12-735950-2.50012-8 Google Scholar 20 Kaplan H, Lancaster J. 2000. The evolutionary economics and psychology of the demographic transition to low fertility. In: L Cronk, N Chagnon, W Irons, editors. Adaptation and human behavior: an anthropological perspective. New York: Aldine de Gruyter. p 283–322. Google Scholar 21 Lancaster J, Kaplan H, Hill K, Hurtado AM. 2000. The evolution of life history, intelligence and diet among chimpanzees and human foragers. In: F Tonneau, NS Thompson, editors. Perspectives in ethology, evolution, culture and behavior. New York: Kluwer Academic. p 47–72. 10.1007/978-1-4615-1221-9_2 Web of Science®Google Scholar 22 Clutton-Brock TH. 2002. Breeding together: kin selection and mutualism in cooperative vertebrates. Science 296: 69–72. Google Scholar 23 Clutton-Brock TH, Brotherton PNM, O'Riain MJ, Griffin AS, Gaynor D, Kansky R, Sharpe L, McIlrath GM. 2001. Contributions to cooperative rearing in meerkats. Anim Behav 61: 705–710. 10.1006/anbe.2000.1631 Web of Science®Google Scholar 24 Cockburn A. 1998. Evolution of helping behavior in cooperatively breeding birds. Ann Rev Ecol Syst 29: 141–177. 10.1146/annurev.ecolsys.29.1.141 Web of Science®Google Scholar 25 Emlen ST. 1991. Evolution of cooperative breeding in birds and mammals. In: JR Krebs, NB Davies, editors. Behavioral ecology: an evolutionary approach, 2nd ed. London: Blackwell Scientific Publications. p 301–337. Google Scholar 26 Skutch AF. 1987. Helpers at birds' nests: a worldwide survey of cooperative breeding and related behavior. Iowa City: University of Iowa Press. Web of Science®Google Scholar 27 NG Solomon, JA French, editors. 1997. Cooperative breeding in mammals. Cambridge: Cambridge University Press. Google Scholar 28 Blurton Jones N, Hawkes K, O'Connell J. 1997. Why do Hadza children forage? In: N Segal, GE Weisfeld, CC Weisfeld, editors. Uniting psychology and biology: integrative perspectives on human development. American Psychological Association. p 164–183. Google Scholar 29 Cain M. 1977. The economic activities of children in a village in Bangladesh. Popul Dev Rev 3: 201–227. 10.2307/1971889 Web of Science®Google Scholar 30 Flinn MV. 1988. Parent-offspring interactions in a Caribbean village: daughter guarding. In: L Betzig, M Borgerhoff Mulder, P Turke, editors. Human reproductive behavior: a Darwinian perspective. Cambridge: Cambridge University Press. p 189–200. Google Scholar 31 Ivey PK. 2000. Cooperative reproduction in Ituri Forest hunter-gatherers: who cares for Efe infants. Curr Anthropol 41: 856–866. 10.1086/317414 Web of Science®Google Scholar 32 Lee RD, Bulatao RA. 1983. The demand for children: a critical essay. In: RA Bulatao, RD Lee, editors. Determinants of fertility in developing countries. New York: Academic Press. p 233–287. Google Scholar 33 Reynolds P. 1991. Dance civet cat: child labour in the Zambezi Valley. Athens: Ohio University Press. Google Scholar 34 Turke P. 1989. Evolution and demand for children. Popul Dev Rev 15: 61–90. 10.2307/1973405 Web of Science®Google Scholar 35 Turke P. 1988. Helpers at the nest: childcare networks on Ifaluk. In: L Betzig, M Borgerhoff Mulder, P Turke, editors. Human reproductive behavior. Cambridge: Cambridge University Press. p 173–188. Google Scholar 36 Bentley G, Jasienska G, Goldberg T. 1993. Is the fertility of agriculturalists higher than that of nonagriculturalists? Curr Anthropol 34: 778–785. 10.1086/204223 Web of Science®Google Scholar 37 French JA. 1997. Proximate regulation of singular breeding in Callitrichid primates. In: NG Solomon, JA French, editors. Cooperative breeding in mammals. Cambridge: Cambridge University Press. p 34–75. Google Scholar 38 Goldizen AW. 1987. Tamarins and marmosets: communal care of offspring. In: B Smuts, D Cheney, R Seyfarth, R Wrangham, T Struhsaker, editors. Primate societies. Chicago: University of Chicago Press. p 34–43. Google Scholar 39 Hrdy SB. 1977. The langurs of Abu. Cambridge: Harvard University Press. Google Scholar 40 Koenig A. 1995. Group size, composition, and reproductive success in wild common marmosets (Callithrix jacchus). Am J Primatol 35. Google Scholar 41 Tardif SD. 1997. The bioenergetics of parental care in marmosets and tamarins. In: NG Solomon, JA French, editors. Cooperative breeding in mammals. Cambridge: Cambridge University Press. p 11–33. Google Scholar 42 Bove RB, Valeggia CR, Ellison PT. 2002. Girl helpers and time allocation of nursing women among the Toba of Argentina. Hum Nat 13: 457–472. 10.1007/s12110-002-1003-8 PubMedWeb of Science®Google Scholar 43 Hames R, Draper P. 2004. Women's work, child care and helpers-at-the-nest in a hunter-gatherer society. Hum Nat 15: 319–341. 10.1007/s12110-004-1012-x PubMedWeb of Science®Google Scholar 44 Hurtado M, Hawkes K, Hill K, Kaplan H. 1985. Female subsistence strategies among Ache hunter-gatherers of eastern Paraguay. Hum Ecol 13: 1–28. 10.1007/BF01531086 Web of Science®Google Scholar 45 Marlowe F. 2003. A critical period for provisioning by Hadza men: implications for pair bonding. Evol Hum Behav 24: 217–229. 10.1016/S1090-5138(03)00014-X Web of Science®Google Scholar 46 Kramer KL. 2004. Reconsidering the cost of childbearing: the timing of children's helping behavior across the life cycle of Maya families. In: M Alvard, editor. Socioeconomic aspects of human behavioral ecology. Amsterdam: Elsevier. p 335–353. 10.1016/S0190-1281(04)23014-1 Web of Science®Google Scholar 47 Bock J. 2002. Learning, life history and productivity: children's lives in the Okavango Delta, Botswana. Hum Nat 13: 161–197. 10.1007/s12110-002-1007-4 PubMedWeb of Science®Google Scholar 48 Bliege Bird R, Bird D. 2002. Constraints of knowing or constraints of growing? Fishing and collecting by the children of Mer. Hum Nat 13: 239–267. 10.1007/s12110-002-1009-2 PubMedWeb of Science®Google Scholar 49 Blurton Jones N, Hawkes K, O'Connell J. 1989. Measuring and modeling costs of children in two foraging societies: implications for schedule of reproduction. In: V Standen, R Foley, editors. Comparative socioecology: the behavioral ecology of humans and other mammals. Oxford: Blackwell Scientific Publications. p 367–390. Google Scholar 50 Draper P, Cashdan E. 1988. Technological change and child behavior among the !Kung. Ethnology 27: 339–365. 10.2307/3773398 Web of Science®Google Scholar 51 Kramer KL. 2002. Variation in juvenile dependence: helping behavior among Maya children. Hum Nat 13: 299–325. 10.1007/s12110-002-1011-8 PubMedWeb of Science®Google Scholar 52 Gould RA. 1980. Living archaeology. Cambridge: Cambridge University Press. Google Scholar 53 Greaves R. n.d. Fishing strategies and technology. Ethnoarchaeological research strategies for Pumé foragers in Venezuela. Google Scholar 54 Hames R. 1992. Time allocation. In: EA Smith, B Winterhalder, editors. Evolutionary ecology and human behavior. New York: Aldine De Gruyter. p 203–235. Google Scholar 55 Winterhalder B. 1983. Opportunity-cost foraging models for stationary and mobile predators. Am Nat 122: 73–84. 10.1086/284119 Web of Science®Google Scholar 56 Kramer KL. 1998. Variation in children's work among modern Maya subsistence agriculturalists. Ph.D. dissertation. University of New Mexico, Albuquerque. Google Scholar 57 Emlen ST, Wrege PH. 1991. Breeding biology of white-fronted bee-eaters at Nakuru: the influence of helpers on breeder fitness. J Anim Ecol 60: 309–326. 10.2307/5462 Web of Science®Google Scholar 58 Fairbanks L. 1990. Reciprocal benefits of allomothering for female vervet monkeys. Anim Behav 40: 553–562. 10.1016/S0003-3472(05)80536-6 Web of Science®Google Scholar 59 Moehlman PD. 1986. Ecology of cooperation in canids. In: DI Rubenstein, RW Wrangham, editors. Ecological aspects of social evolution: birds and mammals. Princeton: Princeton University Press. p 64–86. Google Scholar 60 Wiley RH, Rabenold KN. 1984. The evolution of cooperative breeding by delayed reciprocity and queuing for favorable social positions. Evolution 38: 609–621. 10.1111/j.1558-5646.1984.tb00326.x PubMedWeb of Science®Google Scholar 61 Lee RD, Kaplan H, Kramer KL. 2002. Children and the elderly in the economic life cycle of the household: a comparative study of three groups of horticulturalists and hunter-gatherers. Presented at the Annual Meeting of the Population Association of America, Atlanta, Georgia. Google Scholar 62 Lee RD, Kramer KL. 2002. Children's economic roles in the Maya family life cycle: Cain, Caldwell and Chayanov revisited. Popul Dev Rev 28: 475–499. 10.1111/j.1728-4457.2002.00475.x Web of Science®Google Scholar 63 Kramer KL. 2005. Maya children: helpers at the farm. Cambridge: Harvard University Press. 10.4159/9780674039742 Google Scholar 64 Potts R. 1998. Variability selection in hominid evolution. Evol Anthropol 7: 81–96. 10.1002/(SICI)1520-6505(1998)7:3<81::AID-EVAN3>3.0.CO;2-A Web of Science®Google Scholar 65 Bogin B. 1998. Evolutionary and biological aspects of childhood. In: C Panter-Brick, editor. Biosocial perspectives on children. Cambridge: Cambridge University Press. p 10–44. Google Scholar 66 Galdikas BM, Wood JW. 1990. Birth spacing patterns in humans and apes. Am J Phys Anthropol 83: 185–191. 10.1002/ajpa.1330830207 CASPubMedWeb of Science®Google Scholar 67 Nishida T, Takasaki H, Takahata Y. 1990. Demography and reproductive profiles. In: T Nishida, editor. The chimpanzees of the Mahale Mountains: sexual and life history strategies. Tokyo: University of Tokyo Press. p 63–97. Web of Science®Google Scholar 68 Ivey PK, Morrelli GA, Tronick EZ. 1994. Children's resource acquisition strategies: food-getting among young Efe forager children of the Ituri Forest, Zaire. Paper presented at the Society for Cross-Cultural Research, Santa Fe, NM. Google Scholar 69 Morelli GA. 1997. Growing up female in a foraging and farming community. In: M Zihlman, editor. Female biology, life history, and evolution. Princeton: Princeton University Press. Google Scholar 70 Low BS. 2000. Why sex matters: a Darwinian look at human behavior. Princeton: Princeton University Press. Google Scholar 71 Zeller AC. 1987. A role for women in hominid evolution. Man 22: 528–557. 10.2307/2802504 Web of Science®Google Scholar 72 Kaplan H, Hill K, Lancaster J, Hurtado AM. 2000. A theory of human life history evolution: diet, intelligence, and longevity. Evol Anthropol 9: 156–185. 10.1002/1520-6505(2000)9:4<156::AID-EVAN5>3.0.CO;2-7 Web of Science®Google Scholar 73 Lancaster J. 1997. An evolutionary history of human reproductive strategies and the status of women in relation to population growth and social stratification. In: PA Gowaty, editor. Evolutionary feminism. New York: Chapman and Hall. p 466–488. 10.1007/978-1-4615-5985-6_19 Google Scholar 74 Hrdy SB. 2005. Evolutionary context of human development: the cooperative breeding model. In: DS Carter, L Ahnert, editors. Attachment and bonding: a new synthesis. Cambridge: M.I.T. Press. Google Scholar 75 Hrdy SB. 2005. Comes the child before the man: how cooperative breeding and prolonged postweaning dependence shaped human potentials. In: B Hewlett, M Lamb, editors. Hunter gatherer childhood. Piscataway: Transactions. Google Scholar 76 Smith HB, Tompkins RL. 1995. Toward a life history of the Hominidae. Ann Rev Anthropol 24: 257–279. 10.1146/annurev.an.24.100195.001353 Web of Science®Google Scholar 77 Becker GS. 1981. A treatise on the family. Cambridge: Harvard University Press. Google Scholar 78 Caldwell JC. 1983. Direct economic costs and benefits of children. In: RA Bulatoa, RD Lee, editors. Determinants of fertility in developing countries. New York: Academic Press. p 458–493. Google Scholar 79 Handwerker WP. 1986. The modern demographic transition: an analysis of subsistence choices and reproductive consequences. Am Anthropol 88: 400–417. 10.1525/aa.1986.88.2.02a00070 Web of Science®Google Scholar 80 Becker GS, Lewis HG. 1973. On the interaction between the quantity and quality of children. J Political Econ 81: s279–s288. 10.1086/260166 Web of Science®Google Scholar 81 Caldwell JC. 1977. The economic rationality of high fertility: an investigation illustrated with Nigerian survey data. Popul Stud 31: 5–27. 10.2307/2173485 Web of Science®Google Scholar 82 Kasarda JD. 1971. Economic structure and fertility: a comparative analysis. Demography 8: 307–318. 10.2307/2060619 CASPubMedWeb of Science®Google Scholar 83 Munroe RH, Munroe RL, Shimmin HS. 1984. Children's work in four cultures: determinants and consequences. Am Anthropol 86: 339–379. 10.1525/aa.1984.86.2.02a00120 Web of Science®Google Scholar 84 Nag M, White B, Peet R. 1978. An anthropological approach to the study of the economic value of children in Java and Nepal. Curr Anthropol 19: 293–306. 10.1086/202076 Web of Science®Google Scholar 85 White B. 1975. The economic importance of children in a Javanese village. In: M Nag, editor. Population and social organization. The Hague: Mouton. p 127–146. 10.1515/9783110822168.127 Web of Science®Google Scholar 86 Kaplan H. 1994. Evolutionary and wealth flows theories of fertility: empirical tests and new models. Popul Dev Rev 20: 753–791. 10.2307/2137661 Web of Science®Google Scholar 87 Kramer KL. 2005. Maya children: helpers at the farm. Cambridge: Harvard University Press. 10.4159/9780674039742 Google Scholar 88 Lindert P. 1983. The changing economic costs and benefits of having children. In: RA Bulatao, RD Lee, editors. Determinants of fertility in developing countries. New York: Academic Press. p 494–516. Google Scholar 89 Vlassoff M. 1979. Labour demand and economic utility of children: a case study in rural India. Popul Stud 33: 415–428. 10.2307/2173889 Web of Science®Google Scholar 90 Caldwell JC. 1976. Toward a restatement of demographic transition theory. Popul Dev Rev 2: 321–366. 10.2307/1971615 Web of Science®Google Scholar 91 Lee RD. 2000. A cross-cultural perspective on intergenerational transfers and the economic life cycle. In: A Mason, G Tapinos, editors. Sharing the wealth: demographic change and economic transfers between generations. Oxford: Oxford University Press. p 17–56. Google Scholar 92 Mueller E. 1976. The economic value of children in peasant agriculture. In: R Ridker, editor. Population and development: the search for selective interventions. Baltimore: John Hopkins Press. p 98–153. Web of Science®Google Scholar 93 Stecklov G. 1999. Evaluating the economic returns to childbearing in Côte d'Ivoire. Popul Stud 53: 1–17. 10.1080/00324720308072 Web of Science®Google Scholar 94 Turke P. 1989. Evolution and demand for children. Popul Dev Rev 15: 61–90. 10.2307/1973405 Web of Science®Google Scholar 95 Kramer KL. 2004. Reconsidering the cost of childbearing: the timing of children's helping behavior across the life cycle of Maya families. In: M Alvard, editor. Socioeconomic aspects of human behavioral ecology. Amsterdam: Elsevier. p 335–353. 10.1016/S0190-1281(04)23014-1 Web of Science®Google Scholar 96 Altmann J. 1974. Observational study of behavior: sampling methods. Behaviour 49: 227–267. 10.1163/156853974X00534 CASPubMedWeb of Science®Google Scholar 97 Borgerhoff Mulder M, Caro TM. 1985. The use of quantitative observational techniques in anthropology. Curr Anthropol 26: 323–335. 10.1086/203277 Web of Science®Google Scholar 98 Hames R. 1992. Time allocation. In: EA Smith, B Winterhalder, editors. Evolutionary ecology and human behavior. New York: Aldine De Gruyter. p 203–235. Google Scholar 99 Durnin JV, Passmore R. 1967. Energy, work and leisure. London: Heinemann Educational Books. Google Scholar 100 Ulijaszek S. 1995. Human energetics in biological anthropology. Cambridge: Cambridge University Press. Google Scholar 101 Boserup E. 1965. The conditions for agricultural growth: the economics of agrarian change under population pressure. Chicago: Aldine. Google Scholar 102 Clark C, Haswell M. 1967. The economics of subsistence agriculture. London: Macmillan Press. Google Scholar 103 Ivey PK. 2000. Cooperative reproduction in Ituri Forest hunter-gatherers: who cares for Efe infants. Curr Anthropol 41: 856–866. 10.1086/317414 Web of Science®Google Scholar 104 Lancaster J. 1971. Play mothering: the relations between juvenile females and young infants among free-ranging vervet monkeys (Cercopithicus aethiops). Folia Primatol 15: 161–182. 10.1159/000155377 Web of Science®Google Scholar 105 Blurton Jones N, Hawkes K, Draper P. 1994. Foraging returns of !Kung adults and children: why didn't !Kung children forage? J Anthropol Res 50: 217–248. 10.1086/jar.50.3.3630178 Web of Science®Google Scholar 106 Blurton Jones N, Hawkes K, Draper P. 1994. Differences between Hadza and !Kung children's work: affluence or practical reason. In: ES Burch, LJ Ellana, editors. Key issues in hunter-gatherer research. Berg: Oxford Press. p 189–215. Google Scholar 107 Blurton Jones N, Marlowe FW. 2002. Selection for delayed maturity: does it take 20 years to hunt and gather? Hum Nat 13: 199–238. 10.1007/s12110-002-1008-3 PubMedWeb of Science®Google Scholar 108 Hawkes K, O'Connell J, Blurton Jones N. 1995. Hadza children's foraging: juvenile dependency, social arrangements, and mobility among hunter-gatherers. Curr Anthropol 36: 688–700. 10.1086/204420 Web of Science®Google Scholar 109 Kaplan H. 1997. The evolution of the human life course. In: KW Wackter, CE Finch, editors. Between Zeus and the salmon: the biodemography of longevity. Washington D.C.: National Academy of Sciences. p 175–211. Google Scholar 110 Kaplan H, Lancaster JB, Bock JA, Johnson SE. 1995. Does observed fertility maximize fitness among New Mexican men? A test of an optimality model and a new theory of parental investment in the embodied capital of offspring. Hum Nat 6: 325–360. 10.1007/BF02734205 CASPubMedWeb of Science®Google Scholar 111 Parsons DO, Goldin C. 1989. Parental altruism and self interest: child labor among late-nineteenth century American families. Econ Inquiry 27: 637–659. 10.1111/j.1465-7295.1989.tb00794.x Web of Science®Google Scholar 112 Blurton Jones N, Hawkes K, O'Connell J. 1997. Why do Hadza children forage? In: N Segal, GE Weisfeld, CC Weisfeld, editors. Uniting psychology and biology: integrative perspectives on human development. American Psychological Association. p 164–183. Google Scholar 113 Kramer KL, McMillan GP. 1998. How Maya women respond to changing technology: the effect of helping behavior on initiating reproduction. Hum Nat 9: 205–223. 10.1007/s12110-998-1003-4 CASPubMedWeb of Science®Google Scholar 114 Hames R. 1988. The allocation of parental care among the Ye'Kawana. In: L Betzig, M Borgerhoff Mulder, P Turke, editors. Human reproductive behavior. Cambridge: Cambridge University Press. p 237–251. Google Scholar 115 Goodman M, Griffin P, Estioko-Griffin A, Grove J. 1985. The comparability of hunting and mothering among the Agta humer-gatherers of the Philippines. Sex Roles 12: 1199–1209. 10.1007/BF00287829 Web of Science®Google Scholar 116 Denham WW. 1974. Infant transport among the Alyawara tribe, Central Australia. Oceania 64: 253–277. 10.1002/j.1834-4461.1974.tb01820.x Google Scholar 117 Valeggia CR. n.d. Changing times for the Argentine Toba: who cares for the baby now? In: G Bentley, R Mace, editors. Biosocial Society Symposium Series. Cambridge: Cambridge University Press. Google Scholar 118 Wich SA, Utami-Atmoko SS, Mitra Setia T, Rijksen HR, Schürmann C, van Hooff J, van Schaik CP. 2004. Life history of wild Sumatran orangutans (Pongo abelii). J Hum Evol 47: 385–398. 10.1016/j.jhevol.2004.08.006 CASPubMedWeb of Science®Google Scholar 119 Fossey D. 1979. Development of the mountain gorilla (Gorilla gorilla beringei): the first thirty-six months. In: DA Hamburg, ER McCown, editors. The great apes. Menlo Park: Benjamin-Cummings. p 139–186. Google Scholar 120 Watts DP. 1991. Mountain gorilla reproduction and sexual behavior. Am J Primatol 24: 211–226. 10.1002/ajp.1350240307 Web of Science®Google Scholar 121 Pusey AE. 1983. Mother-offspring relationship in chimpanzees after weaning. Anim Behav 31: 363–377. 10.1016/S0003-3472(83)80055-4 Web of Science®Google Scholar 122 Pusey AE. 1990. Behavioural changes in adolescence in chimpanzees. Behaviour 115: 203–246. 10.1163/156853990X00581 Web of Science®Google Scholar 123 Knott C. 2001. Female reproductive ecology of the apes: implications for human evolution. In: P Ellison, editor. Reproductive ecology and human evolution. New York: Aldine de Gruyter. p 429–463. Google Scholar 124 Eveleth PB, Tanner JM. 1990. Worldwide variation in human growth. Cambridge: Cambridge University Press. Google Scholar 125 Bentley G, Goldberg T, Jasienska G. 1993. The fertility of agricultural and non-agricultural societies. Popul Stud 47: 269–281. 10.1080/0032472031000147006 Web of Science®Google Scholar 126 Howell N. 1979. Demography of the !Kung. New York: Academic Press. Google Scholar 127 Tucker B, Young A, n.d. Growing up Mikea: children's time allocation and tuber foraging in southwest Madagascar. In: B Hewlett, Lamb, editors. Hunter-gatherer children. p 147–171. Google Scholar 128 Johnson A. 1975. Time allocation in a Machiguenga community. Ethnology 14: 301–310. 10.2307/3773258 Web of Science®Google Scholar 129 Minge-Kalman W. 1978. Household economy during the peasant to worker transition in the Swiss Alps. Ethnology 17: 183–196. 10.2307/3773143 Web of Science®Google Scholar 130 Skoufias E. 1994. Market wages, family composition and the time allocation of children in agricultural households. J Dev Stud 30: 335–360. 10.1080/00220389408422318 Web of Science®Google Scholar 131 Erasmus C. 1955. Work patterns in a Maya village. Am Anthropol 57: 322–333. 10.1525/aa.1955.57.2.02a00090 Web of Science®Google Scholar 132 Fratkin E. 1989. Household variation and gender inequality in Ariaal pastoral production: results of a stratified time-allocation survey. Am Anthropol 91: 430–440. 10.1525/aa.1989.91.2.02a00100 Web of Science®Google Scholar 133 Munroe R, Koel A, Munroe R, Bolton R, Michelson C, Bolton C. 1983. Time allocation in four societies. Ethnology 22: 355–370. 10.2307/3773682 Web of Science®Google Scholar 134 Bock J. 1995. The determinants of variation in children's activities in a southern African community. Ph.D. dissertation, University of New Mexico, Albuquerque. Google Scholar 135 Watts, David P. 1991. Mountain gorilla reproduction and sexual behavior. American Journal of Primatology 24: 847–867. 10.1002/ajp.1350240307 Web of Science®Google Scholar Citing Literature Volume14, Issue6November/December 2005Pages 224-237 ReferencesRelatedInformation
Publication Year: 2005
Publication Date: 2005-12-16
Language: en
Type: review
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