Human Nature

, 22:303 | Cite as

Juvenile Subsistence Effort, Activity Levels, and Growth Patterns

Middle Childhood among Pumé Foragers
  • Karen L. KramerEmail author
  • Russell D. Greaves


Attention has been given to cross-cultural differences in adolescent growth, but far less is known about developmental variability during juvenility (ages 3–10). Previous research among the Pumé, a group of South American foragers, found that girls achieve a greater proportion of their adult stature during juvenility compared with normative growth expectations. To explain rapid juvenile growth, in this paper we consider girls’ activity levels and energy expended in subsistence effort. Results show that Pumé girls spend far less time in subsistence tasks in proportion to their body size compared with adults, and they have lower physical activity levels compared with many juveniles cross-culturally. Low activity levels help to explain where the extra energy comes from to support rapid growth in a challenging environment. We suggest that activity levels are important to account for the variation of resource and labor transfers in mediating energy availability.


Juvenility Life history Human growth Physical activity levels (PAL) Hunter-gatherers (Foragers) South American Indians Pumé 



Foremost we thank the people of Doro Aná, Yagurí, and Charakotó for their tireless hours of interviews and measurements. We are grateful to Drs. Roberto Lizarralde (Universidad Central de Venezuela), Ted Gragson (University of Georgia, Athens), and Haydée Seijas (Universidad Central de Venezuela) for their previous census research among the Pumé, which is invaluable in establishing the Pumé age estimates. Much appreciation to Dr. Daisy Barreto (Universidad Central de Venezuela) and Kleismer Correa (Salud Indígena) for assisting with Venezuelan research logistics. We thank Oskar Burger and Amanda Veile for their assistance in the data collection. The 2005–2007 research was funded by the National Science Foundation (0349963) and the Milton Foundation. The 1992–1993 Pumé research was funded by the L.S.B. Leakey Foundation and an NSF dissertation improvement grant awarded to Russell Greaves and Lewis R. Binford (DBS-9123875).


  1. Aiello, L. C., & Key, C. (2002). Energetic consequences of being a Homo erectus female. American Journal of Human Biology, 14, 551–565.Google Scholar
  2. Altmann, J. (1974). Observational study of behavior: Sampling methods. Behaviour, 49, 227–267.Google Scholar
  3. Bailey, R. C., & Peacock, N. R. (1988). Efe pygmies of northeast Zaire: subsistence strategies in the Ituri forest. In I. de Garine & G. A. Harrison (Eds.), Coping with uncertainty in the food supply (pp. 88–117). Oxford: Clarendon Press.Google Scholar
  4. Beunen, G., Thomis, M., Maes, H. H., Loos, R., Malina, R. M., Claessens, A. L., et al. (2000). Genetic variance of adolescent growth in stature. Annals of Human Biology, 27, 173–186.Google Scholar
  5. Biesele, M., & Hitchcock, R. K. (2000). The Ju/’hoansi San under two states. In P. P. Schweitzer, M. Biesele, & R. K. Hitchcock (Eds.), Hunters and gatherers in the modern world: Conflict, resistance, and self-determination (pp. 305–326). New York: Berghan Books.Google Scholar
  6. Bird, D. W., & Bliege Bird, R. L. (2005). Martu children’s hunting strategies in the Western Desert, Australia. In B. S. Hewlett & M. E. Lamb (Eds.), Hunter-gatherer childhoods (pp. 129–146). New Brunswick: AldineTransaction.Google Scholar
  7. Bliege Bird, R., & Bird, D. (2002). Constraints of knowing or constraints of growing? Fishing and collecting by the children of Mer. Human Nature, 13, 239–267.Google Scholar
  8. Blurton Jones, N. (1993). The lives of hunter-gatherer children: Effects of parental behavior and parental reproductive strategy. In M. E. Pereira & L. A. Fairbanks (Eds.), Juvenile primates (pp. 309–326). Oxford: Oxford University Press.Google Scholar
  9. Blurton Jones, N. (2006). Contemporary hunter-gatherers and human life history evolution. In K. Hawkes & R. R. Paine (Eds.), The evolution of human life history (pp. 231–266). Santa Fe: School of American Research Press.Google Scholar
  10. Blurton Jones, N., Hawkes, K., & Draper, P. (1994). Foraging returns of !Kung adults and children: Why didn’t !Kung children forage? Journal of Anthropological Research, 50, 217–248.Google Scholar
  11. 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 (Eds.), Comparative socioecology. The behavorial ecology of humans and other mammals (pp. 367–390). Oxford: Blackwell Scientific Publications.Google Scholar
  12. Blurton Jones, N., Hawkes, K., O’Connell, J. (1997). Why do Hadza children forage? In N. Segal, G. E. Weisfeld, C. C. Weisfeld (Eds.), Uniting psychology and biology: Integrative perspectives on human development (pp. 164–183). American Psychological Association.Google Scholar
  13. Blurton Jones, N., Hawkes, K., & O’Connell, J. F. (1999). Some current ideas about the evolution of human life history. In P. C. Lee (Ed.), Comparative primate socioecology (pp. 140–166). Cambridge: Cambridge University Press.Google Scholar
  14. Blurton Jones, N., & Marlowe, F. W. (2002). Selection for delayed maturity: Does it take 20 years to hunt and gather? Human Nature, 13, 199–238.Google Scholar
  15. 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
  16. Bock, J. (2002a). Learning, life history and productivity: Children’s lives in the Okavango Delta, Botswana. Human Nature, 13, 161–197.Google Scholar
  17. Bock, J. (2002b). Evolutionary demography and intrahousehold time allocation: School attendance and child labor among the Okavango Delta peoples of Botswana. American Journal of Human Biology, 141, 206–222.Google Scholar
  18. Bock, J. (2005). What makes a competent adult forager? In B. S. Hewlett & M. E. Lamb (Eds.), Hunter-gatherer childhoods (pp. 109–128). New Brunswick: Aldine Transaction.Google Scholar
  19. Bock, R. D., & Thissen, D. (1980). Statistical problems of fitting individual growth curves. In F. E. Johnson & A. F. Roche (Eds.), Human physical growth and maturation (pp. 265–290). New York: Plenum Press.Google Scholar
  20. Bogin, B. (1999). Patterns of human growth. Cambridge: Cambridge University Press.Google Scholar
  21. Bogin, B., & Rios, L. (2003). Rapid morphological change in living humans: Implications for modern human origins. Comparative Biochemistry and Physiology Part A, 136, 71–84.Google Scholar
  22. Bogin, B., Wall, M., & MacVean, R. B. (1992). Longitudinal analysis of adolescent growth of Ladino and Mayan school children in Guatemala: Effects of environment and sex. American Journal of Physical Anthropology, 89, 447–457.Google Scholar
  23. Borgerhoff Mulder, M. (1997). Time allocation among the Kipsigis of Kenya. New Haven: Human Relations Area Files, Inc.Google Scholar
  24. Borgerhoff Mulder, M., & Caro, T. M. (1985). The use of quantitative observational techniques in anthropology. Current Anthropology, 26, 323–335.Google Scholar
  25. Brabin, L., & Brabin, B. (1992). The cost of successful adolescent growth and development in girls in relation to iron and vitamin A status. American Journal of Clinical Nutrition, 55, 955–958.Google Scholar
  26. Cain, M. (1977). The economic activities of children in a village in Bangladesh. Population and Development Review, 3, 201–227.Google Scholar
  27. Cameron, N. (1991). Human growth, nutrition and health status in Sub-Saharan Africa. Yearbook of Physical Anthropology, 34, 211–250.Google Scholar
  28. Cameron, N., Gordon-Larsen, P., & Wrchota, E. M. (1994). Longitudinal analysis of adolescent growth in height, fatness, and fat patterning in rural South African Black children. American Journal of Physical Anthropology, 93, 307–321.Google Scholar
  29. Campbell, B. C. (2011). Adrenarche and middle childhood. Human Nature, 22. doi: 10.1007/s12110-011-9120-x.
  30. Charnov, E. L. (1991). Evolution of life history variation among female mammals. Proceedings of the National Academy of Sciences, 88, 1134–1137.Google Scholar
  31. Charnov, E. L., & Berrigan, D. (1993). Why do females primates have such long lifespans and so few babies? Or life in the slow lane. Evolutionary Anthropology, 1, 191–194.Google Scholar
  32. Charnov, E. L., & Schaffer, W. M. (1973). Life history consequences of natural selection: Cole’s result revisited. The American Naturalist, 107, 791–793.Google Scholar
  33. Chisholm, J. S., Quinlivan, J. A., Petersen, R. W., & Coall, D. A. (2005). Early stress predicts age at menarche and first birth, adult attachment, and expected lifespan. Human Nature, 16, 233–265.Google Scholar
  34. Cole, L. C. (1954). The population consequences of life history phenomena. The Quarterly Review of Biology, 29, 103–137.Google Scholar
  35. Cooper, C., Kuh, D., Egger, P., Wadsworth, M., & Barker, D. (1996). Childhood growth and age at menarche. British Journal of Obstetrics and Gynaecology, 103, 814–817.Google Scholar
  36. Derting, T. L., & Compton, S. (2003). Immune response, not immune maintenance, is energetically costly in wild white-footed mice (Peromyscus leucopus). Physiological and Biochemical Zoology, 76, 744–752.Google Scholar
  37. Díaz Ungría, A. G. (1966). Estudio Comparativo de las Caracteristicas Serologicas y Morfologicas Correspondientes a las Poblaciones Guajiro, Guahibo, Guarao y Yaruro. Caracas: Universidad Central de Venezuela.Google Scholar
  38. Draper, P., & Cashdan, E. (1988). Technological change and child behavior among the !Kung. Ethnology, 27, 339–365.Google Scholar
  39. Draper, P., & Howell, N. (2005). The growth and kinship resources of Ju/’hoansi children. In B. S. Hewlett & M. E. Lamb (Eds.), Hunter-gatherer childhoods (pp. 262–281). New Brunswick: Aldine Transaction.Google Scholar
  40. DuBois, E. F. (1937). The mechanisms of heat loss and temperature regulation. Palo Alto: Stanford University Press.Google Scholar
  41. Dufour, D. L., & Piperata, B. A. (2008). Energy expenditure among farmers in developing countries: What do we know? American Journal of Human Biology, 20, 249–258.Google Scholar
  42. Dunbar, R. I. M. (2003). The social brain: Mind, language and society in evolutionary perspective. Annual Review of Anthropology, 3, 163–181.Google Scholar
  43. Durnin, J. V., & Passmore, R. (1967). Energy, work and leisure. London: Heinemann Educational Books.Google Scholar
  44. Early, J. D., & Peters, J. F. (1990). The population dynamics of the Mucajai Yanomama. New York: Academic.Google Scholar
  45. Ellison, P. T. (1981). Prediction of age at menarche from annual height increments. American Journal of Physical Anthropology, 56, 71–75.Google Scholar
  46. Ellison, P. T. (2001). On fertile ground. A natural history of human reproduction. Cambridge: Harvard University Press.Google Scholar
  47. Erasmus, C. (1955). Work patterns in a Mayo village. American Anthropologist, 57, 322–333.Google Scholar
  48. Fratkin, E. (1989). Household variation and gender inequality in Ariaal pastoral production: Results of a stratified time-allocation survey. American Anthropologist, 91, 430–440.Google Scholar
  49. Froment, A. (2001). Evolutionary biology and health of hunter-gatherer populations. In C. Panter-Brick, R. H. Layton, & P. Rowley-Conwy (Eds.), Hunter-gatherers. An interdisciplinary perspective (pp. 239–266). Cambridge: Cambridge University Press.Google Scholar
  50. Gadgil, M., & Bossert, W. H. (1970). Life historical consequences of natural selection. The American Naturalist, 104, 1–24.Google Scholar
  51. Geronimus, A. T. (1992). The weathering hypothesis and the health of African Americans women and infants: Evidence and speculation. Ethnicity & Disease, 2, 207–221.Google Scholar
  52. Gragson, T. L. (1989). Allocation of time to subsistence and settlement in a Ciri Khonome Pumé Village of the Llanos of Apure, Venezuela. Ph.D. dissertation, Pennsylvania State University, Pittsburgh.Google Scholar
  53. Greaves, R. D. (1997a). Ethnoarchaeological investigation of subsistence mobility, resource targeting, and technological organization among Pumé Foragers of Venezuela, Ph.D. dissertation, University of New Mexico, Albuquerque.Google Scholar
  54. Greaves, R. D. (1997b). Hunting and multifunctional use of bows and arrows: Ethnoarchaeology of technological organization among Pumé Hunters of Venezuela. In H. Knecht (Ed.), Projectile technology (pp. 287–320). New York: Plenum Press.Google Scholar
  55. Greaves, R. D. (2006). Forager landscape use and residential organization. In F. Sellet, R. D. Greaves, & P. L. Yu (Eds.), Archaeology and ethnoarchaeology of mobility (pp. 127–152). Gainesville: University Press of Florida.Google Scholar
  56. Gurven, M., & Kaplan, H. (2006). Determinants of time allocation across the lifespan. Human Nature, 17, 1–49.Google Scholar
  57. Gurven, M., & Kaplan, H. (2007). Longevity among hunter-gatherers: A cross-cultural examination. Population and Development Review, 33, 321–365.Google Scholar
  58. Gurven, M., & Walker, R. (2006). Energetic demand of multiple dependents and the evolution of slow human growth. Proceedings of the Royal Society (Biology), 273, 835–841.Google Scholar
  59. Hames, R. (1992). Time allocation. In E. A. Smith & B. Winterhalder (Eds.), Evolutionary ecology and human behavior (pp. 203–235). New York: Aldine de Gruyter.Google Scholar
  60. Hauspie, R. C., & Susanne, C. (1998). Genetics of child growth. In S. Ulijaszek, F. Johnston, & M. Preece (Eds.), Cambridge encyclopedia of human growth and development (pp. 124–128). Cambridge: Cambridge University Press.Google Scholar
  61. Hawkes, K., O’Connell, J., & Blurton Jones, N. (1997). Hadza women’s time allocation, offspring provisioning and the evolution of long postmenopausal life spans. Current Anthropology, 38, 551–577.Google Scholar
  62. Hawkes, K., O’Connell, J., Blurton Jones, N., Alvarez, H., & Charnov, E. (1998). Grandmothering, menopause and the evolution of human life histories. Proceedings of the National Academy of Sciences, 95, 1336–1339.Google Scholar
  63. Hill, K., Boesch, C., Goodall, J., Pusey, A., Williams, J., & Wrangham, R. (2001). Mortality rates among wild chimpanzees. Journal of Human Evolution, 40, 437–450.Google Scholar
  64. Hill, K., Hawkes, K., Hurtado, A. M., & Kaplan, H. (1984). Seasonal variance in the diet of Ache hunter-gatherers in eastern Paraguay. Human Ecology, 12, 145–180.Google Scholar
  65. Hill, K., & Hurtado, A. M. (1996). Ache life history. New York: Aldine de Gruyter.Google Scholar
  66. Hill, K., & Kaplan, H. (1999). Life history traits in humans: Theory and empirical studies. Annual Review of Anthropology, 28, 397–430.Google Scholar
  67. Howell, N. (2000). Demography of the Dobe !Kung. New York: Academic. Originally published in 1979.Google Scholar
  68. Hrdy, S. B. (2009). Mothers and others. Cambridge: Belknap Press of Harvard University Press.Google Scholar
  69. Hurtado, A. M., & Hill, K. (1990). Seasonality in a foraging society: Variation in diet, work effort, fertility and sexual division of labor among the Hiwi of Venezuela. Journal of Anthropological Research, 46, 293–345.Google Scholar
  70. Hurtado, M., Hawkes, K., Hill, K., & Kaplan, H. (1992). Trade-offs between female food acquisition and child care among Hiwi and Ache foragers. Human Nature, 3, 1–28.Google Scholar
  71. Janson, C. H., & van Schaik, C. P. (1993). Ecological risk aversion in juvenile primates: Slow and steady wins the race. In M. E. Pereira & L. Fairbanks (Eds.), Juvenile primates (pp. 57–74). Oxford: Oxford University Press.Google Scholar
  72. Jenike, M. (2001). Nutritional ecology: Diet, physical activity and body size. In C. Panter-Brick, R. H. Layton, & P. Rowley-Conwy (Eds.), Hunter-gatherers. An interdisciplinary approach (pp. 205–238). Cambridge: Cambridge University Press.Google Scholar
  73. Johnson, A. (1975). Time allocation in a Machiguenga community. Ethnology, 14, 301–310.Google Scholar
  74. Jones, M. E., Cockburn, A., Hamede, R., Hawkins, C., Hesterman, H., Lachish, S., et al. (2008). Life-history change in disease-ravaged Tasmanian devil populations. Proceedings of the National Academy of Sciences, 105, 10023–10027.Google Scholar
  75. Kaplan, H. (1996). A theory of fertility and parental investment in traditional and modern human societies. Yearbook of Physical Anthropology, 39, 91–135.Google Scholar
  76. Kaplan, H., Hill, K., Lancaster, J. B., & Hurtado, A. M. (2000). A theory of human life history evolution: Diet, intelligence, and longevity. Evolutionary Anthropology, 9, 156–185.Google Scholar
  77. Kaplan, H., & Lancaster, J. B. (2000). The evolutionary economics and psychology of the demographic transition to low fertility. In L. Cronk, N. Chagnon, & W. Irons (Eds.), Adaptation and human behavior: An anthropological perspective (pp. 283–322). New York: Aldine de Gruyter.Google Scholar
  78. Kasarda, J. D. (1971). Economic structure and fertility: A comparative analysis. Demography, 8, 307–318.Google Scholar
  79. Kramer, K. L. (1998). Variation in children’s work among modern Maya subsistence agriculturalists. PhD dissertation, University of New Mexico, Albuquerque.Google Scholar
  80. Kramer, K. L. (2002). Variation in juvenile dependence: Helping behavior among Maya children. Human Nature, 13, 299–325.Google Scholar
  81. Kramer, K. L. (2004). Reconsidering the cost of childbearing: The timing of children’s helping behavior across the life cycle of Maya families. In M. Alvard (Ed.), Socioeconomic aspects of human behavioral ecology (pp. 335–353). Amsterdam: Elsevier.Google Scholar
  82. Kramer, K. L. (2005a). Maya children: Helpers at the farm. Cambridge: Harvard University Press.Google Scholar
  83. Kramer, K. L. (2005b). Children’s help and the pace of reproduction: Cooperative breeding in humans. Evolutionary Anthropology, 14, 224–237.Google Scholar
  84. Kramer, K. L. (2008). Early sexual maturity among Pumé foragers of Venezuela: Fitness implications of teen motherhood. American Journal of Physical Anthropology, 136, 338–350.Google Scholar
  85. Kramer, K. L., & Boone, J. L. (2002). Why intensive agriculturalists have higher fertility: A household labor budget approach to subsistence intensification and fertility rates. Current Anthropology, 43, 511–517.Google Scholar
  86. Kramer, K. L., & Ellison, P. T. (2010). Pooled energy budgets: Resituating human energy allocation trade-offs. Evolutionary Anthropology, 19, 136–147.Google Scholar
  87. Kramer, K. L., & Greaves, R. D. (2007). Changing patterns of infant mortality and fertility among Pumé foragers and horticulturalists. American Anthropologist, 109, 713–726.Google Scholar
  88. Kramer, K. L., & Greaves, R. D. (2010). Synchrony between growth and reproductive patterns in human females: Rapid juvenile growth among Pumé foragers. American Journal of Physical Anthropology, 141, 235–244.Google Scholar
  89. Kramer, K. L., Greaves, R. D., & Ellison, P. T. (2009). Early reproductive maturity among Pumé foragers. Implications of a pooled energy model to fast life histories. American Journal of Human Biology, 21, 430–437.Google Scholar
  90. Lampl, M., Veldhuis, J. D., & Johnson, M. L. (1992). Saltation and stasis: A model of human growth. Science, 258, 801–803.Google Scholar
  91. Lancaster, J. B., Kaplan, H., Hill, K., & Hurtado, A. M. (2000). The evolution of life history, intelligence and diet among chimpanzees and human foragers. In F. Tonneau & N. S. Thompson (Eds.), Perspectives in ethology. Evolution, culture and behavior (pp. 47–72). New York: Kluwer.Google Scholar
  92. Lee, R. D., & Kramer, K. L. (2002). Children’s economic roles in the Maya family life cycle: Cain, Caldwell and Chayanov revisited. Population and Development Review, 28, 475–499.Google Scholar
  93. Leigh, S. R. (1996). Evolution of human growth spurts. American Journal of Physical Anthropology, 101, 455–474.Google Scholar
  94. Leonard, W. R. (2003). Measuring human energy expenditure: What have we learned from the flex-heart rate method? American Journal of Human Biology, 15, 479–489.Google Scholar
  95. Leonard, W. R., & Roberson, M. L. (1992). Nutritional requirements and human evolution: A bioenergetics model. American Journal of Human Biology, 4, 179–195.Google Scholar
  96. Leonard, W. R., & Roberson, M. L. (1996). On diet, energy metabolism and brain size in human evolution. Current Anthropology, 37, 125–129.Google Scholar
  97. Leonard, W. R., & Roberson, M. L. (1997). Comparative primate energetics and hominid evolution. American Journal of Physical Anthropology, 102, 265–281.Google Scholar
  98. Martin, L. B., II, Scheueriein, A., & Wikelski, M. (2003). Immune activity elevates energy expenditure of house sparrows: A link between direct and indirect costs. Proceedings of the Royal Society B, 270, 153–158.Google Scholar
  99. McDade, T. W. (2003). Life history theory and the immune system: Steps toward a human ecological immunology. Yearbook of Physical Anthropology, 46, 100–125.Google Scholar
  100. McDade, T. W., Reyes-Garcia, V., Tanner, S., Huanca, T., & Leonard, W. R. (2008). Maintenance versus growth: Investigating the costs of immune activation among children in lowland Bolivia. American Journal of Physical Anthropology, 136, 478–484.Google Scholar
  101. Migliano, A. B., Vinicius, L., & Lahr, M. M. (2007). Life history trade-offs explain the evolution of human pygmies. Proceedings of the National Academy of Sciences, 104, 20216–20219.Google Scholar
  102. Mitrani, P. (1988). Los Pumé (Yaruro). In J. Lizot (Ed.), Los Aborígenes de Venezuela, vol. III, Etnología Contemporánea II (pp. 147–213). Caracas: Fundación La Salle de Ciencias Naturales.Google Scholar
  103. Montgomery, E., & Johnson, A. (1977). Machiguenga energy expenditure. Ecology of Food and Nutrition, 6, 97–105.Google Scholar
  104. Nag, M., White, B., & Peet, R. (1978). An anthropological approach to the study of the economic value of children in Java and Nepal. Current Anthropology, 19, 293–306.Google Scholar
  105. National Academy of Sciences (Ed.). (1989). Recommended dietary allowances. Washington: National Academy Press.Google Scholar
  106. Olsen, E. M., Heino, M., Lilly, G. R., Morgan, M. J., Brattey, J., Ernande, B., et al. (2004). Maturation trends indicative of rapid evolution preceded the collapse of northern cod. Nature, 428, 932–935.Google Scholar
  107. Orr, C. M., Dufour, D. L., & Patton, J. Q. (2001). A comparison of anthropometric indices of nutritional status in Tukanoan and Achuar Amerindians. American Journal of Human Biology, 13, 301–309.Google Scholar
  108. Ots, I., Kerimov, A. B., Ivankina, E. V., Ilyina, T. A., & Hôrak, P. (2001). Immune challenge affects basal metabolic activity in wintering great tits. Proceedings of the Royal Society B, 268, 1175–1181.Google Scholar
  109. Popkin, B. M., & Gordon-Larsen, P. (2004). The nutrition transition: Worldwide obesity dynamics and their determinants. International Journal of Obesity, 28, S2–S9.Google Scholar
  110. Promislow, D. E. L., & Harvey, P. H. (1990). Living fast and dying young: A comparative analysis of life-history variation among mammals. Journal of Zoology, 220, 417–437.Google Scholar
  111. Quinlan, R. J., Quinlan, M. B., & Flinn, M. V. (2005). Local resource enhancement and sex-biased breastfeeding in a Caribbean community. Current Anthropology, 46, 471–480.Google Scholar
  112. Reynolds, P. (1991). Dance civet cat. Child labour in the Zambezi Valley. Athens: Ohio University Press.Google Scholar
  113. Ryan, A. S. (1997). Iron-deficiency anemia in infant development: Implications for growth, cognitive development, resistance to infection and iron supplementation. Yearbook of Physical Anthropology, 40, 25–62.Google Scholar
  114. Sackett, R. D. (1996). Time, energy and the indolent savage. Ph.D. dissertation, University of California, Los Angeles.Google Scholar
  115. Salzano, F. M., & Callegari-Jacques, S. M. (1988). South American Indians. A case study in evolution. Oxford: Clarendon.Google Scholar
  116. Sellen, D. W. (1999). Growth patterns among semi-nomadic pastoralists (Datoga) of Tanzania. American Journal of Physical Anthropology, 109, 187–209.Google Scholar
  117. Sellen, D. W. (2006). Lactation, complementary feeding, and human life history. In K. Hawkes & R. R. Paine (Eds.), The evolution of human life history (pp. 155–196). Santa Fe: School of American Research Press.Google Scholar
  118. Skoufias, E. (1994). Market wages, family composition and the time allocation of children in agricultural households. Journal of Development Studies, 30, 335–360.Google Scholar
  119. Smith, C. C., & Fretwell, S. D. (1974). The optimal balance between size and number of offspring. The American Naturalist, 108, 499–506.Google Scholar
  120. Spear, B. A. (2002). Adolescent growth and development. Journal of the American Dietetic Association Supplement, 102, S23–S29.Google Scholar
  121. Stearns, S. C. (1992). The evolution of life histories. Oxford: Oxford University Press.Google Scholar
  122. Stearns, S. C., & Koella, J. C. (1986). The evolution of phenotypic plasticity in life-history traits: Predictions of reaction norms for age and size at maturity. Evolution, 40, 893–913.Google Scholar
  123. Stettler, N., Schutz, Y., Whitehead, R., & Jequier, E. (1992). Effect of malaria and fever on energy-metabolism in Gambian children. Pediatric Research, 31, 102–106.Google Scholar
  124. Sugiyama, L. S., & Chacon, R. (2000). Effects of illness and injury on foraging among the Yora and Shiwiar: Pathology risk as adaptive problem. In L. Cronk, N. Chagnon, & W. Irons (Eds.), Adaptation and human behavior. An anthropological perspective (pp. 371–395). New York: Aldine de Gruyter.Google Scholar
  125. Sugiyama, L. S., & Chacon, R. (2005). Juvenile responses to household ecology among the Yora of Peruvian Amazonia. In B. S. Hewlett & M. E. Lamb (Eds.), Hunter-gatherer childhoods (pp. 237–261). New Brunswick: Aldine Transaction.Google Scholar
  126. Tanner, J. M., & Cameron, N. (1980). Investigation of the mid-growth spurt in height, weight and limb circumferences in single-year velocity data from London 1966–67. Annals of Human Biology, 7, 565–577.Google Scholar
  127. Thomis, M. A., & Towne, B. (2006). Genetic determinants of prepubertal and pubertal growth and development. Food and Nutrition Bulletin, 27, s257–s278.Google Scholar
  128. Tucker, B., & Young, A. (2005). Growing up Mikea. Children’s time allocation and tuber foraging in southwest Madagascar. In B. S. Hewlett & M. E. Lamb (Eds.), Hunter-gatherer childhoods (pp. 147–171). New Brunswick: Aldine Transaction.Google Scholar
  129. Turke, P. (1988). Helpers at the nest: Childcare networks on Ifaluk. In L. Betzig, M. Borgerhoff Mulder, & P. Turke (Eds.), Human reproductive behavior (pp. 173–188). Cambridge: Cambridge University Press.Google Scholar
  130. Ulijaszek, S. (1995). Human energetics in biological anthropology. Cambridge: Cambridge University Press.Google Scholar
  131. Ulijaszek, S. (2006). The international growth standard for children and adolescents project: Environmental influences on preadolescent and adolescent growth in weight and height. Food and Nutrition Bulletin, 27, s279–s294.Google Scholar
  132. Walker, R., & Hamilton, M. J. (2008). Life-history consequences of density dependence and the evolution of human body size. Current Anthropology, 49, 115–122.Google Scholar
  133. Walker, R., Hill, K., Burger, O., & Hurtado, A. M. (2006). Life in the slow lane revisited: Ontogenetic separation between chimpanzees and humans. American Journal of Physical Anthropology, 129, 577–583.Google Scholar
  134. Walker, R., Gurven, M., Hill, K., Migliano, A., Chagnon, N., De Souza, R., et al. (2006). Growth rates and life histories in twenty-two smale-scale societies. American Journal of Human Biology, 18, 295–311.Google Scholar
  135. West, G., Brown, J. H., & Enquist, B. (2001). A general model for ontogenetic growth. Nature, 413, 628–631.Google Scholar
  136. White, B. (1975). The economic importance of children in a Javanese village. In M. Nag (Ed.), Population and social organization (pp. 127–146). The Hague: Mouton.Google Scholar
  137. Williams, G. C. (1966). Adaptation and natural selection. Princeton: Princeton University Press.Google Scholar
  138. Wilson, M., & Daly, M. (1997). Life expectancy, economic inequality, homicide and reproductive timing in Chicago neighborhoods. British Medical Journal, 314, 1271–1274.Google Scholar
  139. Winterhalder, B. (1983). Opportunity-cost foraging models for stationary and mobile predators. The American Naturalist, 122, 73–84.Google Scholar
  140. Zeller, A. C. (1987). A role for women [sic: Children] in hominid evolution. Man, 22, 528–557.Google Scholar

Copyright information

© Springer Science + Business Media, LLC 2011

Authors and Affiliations

  1. 1.Department of Human Evolutionary BiologyHarvard UniversityCambridgeUSA
  2. 2.Peabody Museum of Archaeology and EthnologyHarvard UniversityCambridgeUSA

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