Human Nature

, Volume 17, Issue 1, pp 1–49 | Cite as

Determinants of time allocation across the lifespan

A theoretical model and an application to the Machiguenga and Piro of Peru
  • Michael Gurven
  • Hillard Kaplan


This paper lays the groundwork for a theory of time allocation across the life course, based on the idea that strength and skill vary as a function of age, and that return rates for different activities vary as a function of the combination of strength and skills involved in performing those tasks. We apply the model to traditional human subsistence patterns. The model predicts that young children engage most heavily in low-strength/low-skill activities, middle-aged adults in high-strength/high-skill activities, and older adults in low-strength/high-skill activities. Tests among Machiguenga and Piro forager-horticulturalists of southeastern Peru show that males and females focus on low-strength/low-skill tasks early in life (domestic tasks and several forms of fishing), switch to higher-strength/higher-skill activities in their twenties and thirties (hunting, fishing, and gardening for males; fishing and gardening for females), and shift focus to high-skill activities late in life (manufacture/repair, food processing).

Key words

Behavioral ecology Family Hunter-gatherers Life history theory Time allocation 


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  1. Alvard, M. S. 1993 Testing the Ecologically Noble Savage Hypothesis. Ph.D. dissertation, University of New Mexico, Albuquerque.Google Scholar
  2. Baksh, M. 1984 Cultural Ecology and Change of the Machiguenga Indians of the Peruvian Amazon. Ph.D. dissertation, Department of Anthropology, University of California, Los Angeles.Google Scholar
  3. Becker, G. S. 1991 A Treatise on the Family, enlarged ed. Cambridge: Harvard University Press.Google Scholar
  4. Bird, D. W., and R. Bliege Bird 2002 Children on the Reef. Human Nature 13:269–297.CrossRefGoogle Scholar
  5. Bird, R. 1999 Cooperation and Conflict: The Behavioral Ecology of the Sexual Division of Labor. Evolutionary Anthropology 8(2):65–75.CrossRefGoogle Scholar
  6. Bliege Bird, R. and D. W. Bird 2002 Constraints of Knowing or Constraints of Growing? Human Nature 13:239–267.CrossRefGoogle Scholar
  7. Blurton Jones, N. G., and F. W. Marlowe 2002 Selection for Delayed Maturity: Does It Take 20 Years to Learn to Hunt and Gather? Human Nature 13:199–238.CrossRefGoogle Scholar
  8. Blurton Jones, N. G., K. Hawkes, and P. Draper 1994 Differences between Hadza and !Kung Children’s Work: Original Affluence or Practical Reason? In Key Issues in Hunter-Gatherer Research, E. S. Burch, ed. Pp. 189–215. Oxford: Berg.Google Scholar
  9. Bock, J. 1995 The Determinants of Variation in Children’s Activities in a Southern African Community. Ph.D. dissertation, Department of Anthropology, University of New Mexico, Albuquerque.Google Scholar
  10. 2002a Learning, Life History, and Productivity: Children’s Lives in the Okavango Delta of Botswana. Human Nature 13:161–198.CrossRefGoogle Scholar
  11. 2002b Evolutionary Demography and Intrahousehold Time Allocation: Schooling and Children’s Labor among the Okavango Delta Peoples of Botswana. American Journal of Human Biology 14:206–221.CrossRefGoogle Scholar
  12. 2004a Farming, Foraging, and Children’s Play in the Okavango Delta, Botswana. In The Nature of Play: Great Apes and Humans, A. Pellegrini and P.K. Smith, eds. Pp. 254–281. New York: Guilford.Google Scholar
  13. 2004b What Makes a Competent Adult Forager? In Hunter-Gatherer Childhoods, B. Hewlett and M. Lamb, eds. Pp. 109–128. Piscataway, New Jersey: Aldine/Transaction.Google Scholar
  14. Bock, J., and S. Johnson 2004 Play and Subsistence Ecology among the Okavango Delta Peoples of Botswana. Human Nature 15:63–81.CrossRefGoogle Scholar
  15. Bock, J., and D. W. Sellen 2002 Childhood and the Evolution of the Human Life Course: An Introduction. Human Nature 13:153–161.CrossRefGoogle Scholar
  16. Cain, M. T. 1977 The Economic Activities of Children in a Village in Bangladesh. Population and Development Review 3:201–227.CrossRefGoogle Scholar
  17. 1981 Extended Kin, Patriarchy, and Fertility. Liege, Belgium: International Union for the Scientific Study of Population, Committee on Comparative Analysis of Fertility.Google Scholar
  18. Caldwell, J. C. 1982 Theory of Fertility Decline. London and New York: Academic Press.Google Scholar
  19. Caro, T. M. 1988 Adaptive Significance of Play: Are We Getting Closer? Trends in Ecology and Evolution 3:50–53.CrossRefGoogle Scholar
  20. Charnov, E. L. 1993 Life History Invariants. Oxford: Oxford University Press.Google Scholar
  21. Draper, P. 1975 !Kung Women: Contrasts in Sexual Egalitarianism in Foraging and Sedentary Contexts. In Toward an Anthropology of Women, edited by R. Reiter, pp. 77–109. New York: Monthly Review Press.Google Scholar
  22. Fagen, R. 1981 Animal Play Behavior. New York: Oxford University Press.Google Scholar
  23. Gow, P. 2001 An Amazonian Myth and Its History. Oxford: Oxford University Press.Google Scholar
  24. Hames, R. 1979 A Comparison of the Efficiencies of the Shotgun and Bow in Neotropical Forest Hunting. Human Ecology 7:219–252.CrossRefGoogle Scholar
  25. 1989 Time, Efficiency, and Fitness in the Amazonian Protein Quest. Journal of Economic Anthropology 11:43–45.Google Scholar
  26. 1992 Time Allocation. In Evolutionary Ecology and Human Behavior, E. A. Smith and B. Winterhalder, eds. Pp. 203–236. New York: Aldine de Gruyter.Google Scholar
  27. Hawkes, K. 2003 Grandmothers and the Evolution of Human Longevity. American Journal of Human Biology 15:380–400.CrossRefGoogle Scholar
  28. Hawkes, K., and R. Bliege Bird 2002 Showing Off, Handicap Signaling and the Evolution of Men’s Work. Evolutionary Anthropology 11:58–67.CrossRefGoogle Scholar
  29. Hawkes, K., K. Hill, J. O’Connell, and E. L. Charnov 1985 How Much Is Enough? Hunters and Limited Needs. Ethology and Sociobiology 6:3–15.CrossRefGoogle Scholar
  30. Hawkes, K., J. F. O’Connell, et al. 1998 Grandmothering, Menopause, and the Evolution of Human Life Histories. Proceedings of the National Academy of Science 95:1336–1339.CrossRefGoogle Scholar
  31. Hill, K., and A. Hurtado 1996 Ache Life History: The Ecology and Demography of a Foraging People. New York: Aldine de Gruyter.Google Scholar
  32. Huet, S., A. Bouvier, M. Gruet, and E. Jolivet 1996 Statistical Tools for Non-linear Regression. New York: Springer-Verlag.Google Scholar
  33. Hurtado, A. M., and K. Hill 1990 Experimental Studies of Tool Efficiency among Machiguenga Women and Implications for Root-digging Foragers. Journal of Anthropological Research 35:207–217.Google Scholar
  34. Hurtado, A. M., et al. 1985 Female Subsistence Strategies among Ache Hunter-Gatherers of Eastern Paraguay. Human Ecology 13:29–47.CrossRefGoogle Scholar
  35. Hurtado, A. M., K. Hill, H. Kaplan, and I. Hurtado 1992 Tradeoffs between Female Food Acquisition and Childcare among Hiwi and Ache Foragers. Human Nature 3:185–216.Google Scholar
  36. Janson, C. H., and C. P. Van Schaik 1993 Ecological Risk Aversion in Juvenile Primates: Slow and Steady Wins the Race. In Juvenile Primates: Life History, Development and Behavior, M. Pereira and L. Fairbanks, eds. Pp. 57–76. New York: Oxford University Press.Google Scholar
  37. Johnson, A. 1975 Time Allocation in a Machiguenga Community. Ethnology 14:301–310.CrossRefGoogle Scholar
  38. 2003 Families of the Forest: The Matsigenka Indians of the Peruvian Amazon. Berkeley: University of California Press.Google Scholar
  39. Johnson, S. E., and J. Bock 2004 Trade-offs in Skill Acquisition and Time Allocation among Juvenile Chacma Baboons. Human Nature 15:45–62.CrossRefGoogle Scholar
  40. Kaplan, H. 1994 Evolutionary and Wealth Flows Theories of Fertility: Empirical Tests and New Models. Population and Development Review 20:753–791.CrossRefGoogle Scholar
  41. 1996 A Theory of Fertility and Parental Investment in Traditional and Modern Human Societies. Yearbook of Physical Anthropology 39:91–135.CrossRefGoogle Scholar
  42. 1997 The Evolution of the Human Life Course. In Between Zeus and Salmon: the Biodemography of Aging, K. Wachter and C. Finch, eds. Pp. 175–211. Washington, D.C.: National Academy of Sciences.Google Scholar
  43. Kaplan, H., and A. Robson 2002 the Co-evolution of Intelligence and Longevity and the Emergence of Humans. Proceedings of the National Academy of Sciences 99:10221–10226.CrossRefGoogle Scholar
  44. Kaplan, H., J. Lancaster, et al. 2003 Embodied Capital and the Evolutionary Economics of the Human Lifespan. Population and Development Review 29 (Supplement):152–182.Google Scholar
  45. Kaplan, H., K. Hill, J. Lancaster, and A. M. Hurtado 2000 A Theory of Human Life History Evolution: Diet, Intelligence, and Longevity. Evolutionary Anthropology 9:156–185.CrossRefGoogle Scholar
  46. Kelly, R. L. 1983 Hunter-Gatherer Mobility Strategies. Journal of Anthropological Research 29:277–306.Google Scholar
  47. Kopischke, K. 2001 Talkng to Children, Caring for Children: A Comparative Analysis of Modern and Traditional Communication Environments. M.A. thesis, University of New Mexico, Albuquerque.Google Scholar
  48. Kramer, K. 2002 Variation in Duration of Juvenile Dependence: Helping Behavior among Maya Children. Human Nature 13:299–325.CrossRefGoogle Scholar
  49. Kramer, K., and J. Boone 2002 Why Intensive Agriculturalists Have Higher Fertility: A Household Labor Budget Approach to Subsistence Intensification and Fertility Rates. Current Anthropology 43:511–517.CrossRefGoogle Scholar
  50. Kumar, S. K., and D. Hotchkiss 1988 Consequences of Deforestation for Women’s Time Allocation, Agricultural Production, and Nutrition in Hill Areas of Nepal. International Food Policy Research Institute, Research Report 69. Washington, D.C.Google Scholar
  51. Lee, R. 1996 A Cross-Cultural Perspective on Intergenerational Transfers and the Economic Life Cycle. In Seminar on Intergenerational Economic Relations and Demographic Change: Papers 16:1–25. Liege, Belgium: International Union for the Scientific Study of Population [IUSSP], Committee on Economic Demography.Google Scholar
  52. Lee, R., and K. Kramer 2002 Children’s Economic Roles in the Maya Family Life Cycle: Cain, Caldwell and Chayanov Revisited. Population and Development Review 28:475–499.CrossRefGoogle Scholar
  53. Lee, Ronald D., Karen L. Kramer, and Hillard Kaplan 2002 Children and the Elderly in the Economic Life Cycle of the Household: A Comparative Study of Three Groups of Horticulturalists and Hunter-Gatherers. Paper presented at the annual meeting of the Population Association of America, Atlanta.Google Scholar
  54. Munroe, R. H., A. Koel, R. L. Munroe, R. Bolton, C. Michelson, and C. Bolton 1983 Time Allocation in Four Societies. Ethnology 22:355–370.CrossRefGoogle Scholar
  55. Nag, M., R. C. Peet, and B. White 1977 Economic Value of Children in Two Peasant Societies. International Union for the Scientific Study of Population 1977:123–139.Google Scholar
  56. Nerlove, M. 1965 Estimation and Identification of Cobb-Douglas Production Functions. Skokie, Illinois: Rand-McNally.Google Scholar
  57. Ratkowsky, D. A. 1990 Handbook of Nonlinear Regression Models. New York: Marcel Dekker.Google Scholar
  58. Robson, A., and H. Kaplan 2003 The Evolution of Human Life Expectancy and Intelligence in Hunter-Gatherer Economies. American Economic Review 93:150–169.CrossRefGoogle Scholar
  59. Roff, D. A. 1992 The Evolution of Life Histories. London: Chapman and Hall.Google Scholar
  60. Salisbury, R. 1962 From Stone to Steel. Cambridge: Cambridge University Press.Google Scholar
  61. Smith, E. A. 1987 On Fitness Maximization, Limited Needs, and Hunter-Gatherer Time-Allocation. Ethology and Sociobiology 8:73–85.CrossRefGoogle Scholar
  62. Stearns, S. 1992 The Evolution of Life Histories. Oxford University Press.Google Scholar
  63. Tiefenthaler, J. 1997 Fertility and Family Time Allocation in the Philippines. Population and Development Review 23:377–397.CrossRefGoogle Scholar
  64. Tooby, J., and I. DeVore 1987 The Reconstruction of Hominid Behavioral Evolution through Strategic Modeling. In The Evolution of Human Behavior: Primate Models, edited by W. G. Kinzey, pp. 183–237. Albany: SUNY Press.Google Scholar
  65. Turke, P. W. 1991 Theory and Evidence on Wealth Flows and Old-Age Security: A Reply to Fricke. Population and Development Review 17:687–702, 756, 758.CrossRefGoogle Scholar
  66. van den Berghe, P. L. 1979 Human Family Systems: An Evolutionary View. New York: Elsevier.Google Scholar
  67. Walker, R., K. Hill, and G. McMillan 2002 Age-Dependency in Skill, Strength and Hunting Ability among the Ache of Eastern Paraguay. Journal of Human Evolution 42:639–657.CrossRefGoogle Scholar
  68. Winterhalder, B. 1983 Opportunity-Cost Foraging Models for Stationary and Mobile Predators. American Naturalist 122:73–84.CrossRefGoogle Scholar

Copyright information

© Transaction Publishers 2006

Authors and Affiliations

  1. 1.University of New MexicoUSA
  2. 2.Department of AnthropologyUniversity of California, Santa BarbaraSanta Barbara

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