Publications

  • Amir, D & D Melnikoff, F Warneken, PR Blake, J Corbit, TC Callaghan, O Barry, A Bowie, L Kleutsch, KL Kramer, E Ross, H Vongsachang, R Wrangham & K McAuliffe (2023). Computational signatures of inequity aversion in children across seven societie. Journal of Experimental Psychology. Published, 05/08/2023.
  • Ross, CT & Hooper, PL, Smith, JE ... KL Kramer, et al. (2023). Reproductive inequality in humans and other mammals . PNAS. Accepted, 04/17/2023.
  • Campbell, B & J Hackman & KL Kramer (2023). Development of adiposity among Ju/'Hoansi hunter-gatherers. American Journal of Biological Anthropology. Published, 02/22/2023.
  • Silva-Caballero, A & HL Ball, KL Kramer and GR Bentley (2023). Sleep deprivation among adolescents in urban and indigenous-rural Mexican communities . Scientific Reports. Vol. 13(1), 1058. Published, 02/2023.
    https://doi.org/10.1038/s41598-023-28330-8
  • Fox, S & KL Kramer, J Silk & B Scelza (2022). Cooperation among Women: Evolutionary and Cross-Cultural Perspectives. Vol. 378, Philosophical Transactions of the Royal Society, B. Published, 06/2022.
  • Hackman, J & KL Kramer (2022). Kin networks shape opportunities for reproductive cooperation, not conflict among hunter-gatherers . Philosophical Transactions, B. Vol. 372, 1868. Published, 06/2022.
  • Fox, S & B Scelza, J Silk, KL Kramer (2022). New perspectives on the evolution of women’s cooperation. Philosophical Transactions, B. Vol. 372, 1868. Published, 06/2022.
  • Kramer, KL (2022). Female cooperation. evolutionary, cross-cultural & ethnographic evidence . Philosophical Transactions of the Royal Society, B. Vol. 372 (1868): doi.org/10.1098/rs. Published, 06/2022.
  • Lew-Levy, S. & R Reckin, S Kissler, I Pretelli, AH Boyette, AN Crittenden, RV Hagen, R Haas, KL Kramer, J Koster, M O’Brien, K Sonoda, TA Surovell, J Stieglitz, B Tucker, N Lavi, K Ellis-Davies & HE Davis (2022). Socioecology shapes child and adolescent activity budgets in twelve hunter-gatherer and mixed-subsistence forager societies . Scientific Reports. Vol. 12, e8054. Published, 03/2022.
  • Schacht, R. & SR Beissinger, C Wedekind, M Jennions, B Geffroy, A Liker, PM Kappeler, FJ Weissing, KL Kramer, T Hesketh, J Boissier, C Uggla, M Hollingshaus & T Székely (2022). Adult sex ratios: causes of variation and implications for animal and human societies . Communications Biology. Vol. 5(1), 1273. Published, 03/2022.
  • Pisor, AC & X Basurto, KG Douglass, KJ Mach, E Ready, JM Tylianakis, A Hazel, MA Kline, KL Kramer, JS Lansing, M Moritz, PE Smaldino, TF Thornton, JH Jones (2022). Effective climate-change adaptation means supporting community autonomy . Nature Climate Change. 1-3. Published, 02/28/2022.
  • Veile, A. & KL Kramer & E Otárola-Castillo (2022). Household conditions modulate associations between cesarean delivery and childhood growth. American Journal of Biological Anthropology. Vol. 179(1), 85-103. Published, 02/2022.
  • KL Kramer & A Veile, P Ivey Henry (2021). Conceiving reproduction in biological anthropology. , S Han & C Tomori (eds). Routledge Handbooks.. (pp. Chapter 1:19-35). The Routledge Handbook of Anthropology & Reproduction. Published, 11/01/2021.
  • Kramer, KL & BC Campbell, A Achenbach & J Hackman (2021). Sex differences in adipose development in a hunter-gatherer population. American Journal of Human Biology. Vol. 34(2), ajhb.23688. Published, 09/02/2021.
  • J Hackman & KL Kramer (2021). Kin ties and market integration in the Mayan Yucatan. Social Sciences, special issue on the Behavioral Ecology of the Family. Vol. 10 (216), 1-19. Published, 07/01/2021.
    https://doi.org/10.3390/ socsci10060216
  • Jones, JH & A Pisor, KG Douglass, R Bliege Bird, E Ready, A Hazel &, J Hackman, KL Kramer, TA Kohler, H Pontzer, MC Towner (2021). How can evolutionary and biological anthropologists engage broader audiences . American Journal of Human Biology, invited issue on Climate Change. Vol. 33(4), e23592. Published, 07/01/2021.
    https:\\ doi:10.1002/ajhb.23592
  • Padilla-Iglesias, C & KL Kramer (2021). The role of language in structuring social networks following market integration in a Yucatec Maya population. Frontiers in Psychology. doi.org/10.3389/fpsyg.2021.656963. Published, 06/01/2021.
  • J Hackman & KL Kramer (2021). Balancing fertility and livelihood diversity in mixed economies . PLoS One. Vol. 16(6), e0253535. Published, 06/01/2021.
  • Kramer, KL (2021). The human family: Its evolutionary context and diversity. Social Sciences, special issue on the Behavioral Ecology of the Family. Vol. 10(6), 1-17. Published, 05/25/2021.
    https://doi.org/10.3390/socsci10060191
  • KL Kramer & JV Hackman, R Schacht & HE Davis (2021). Effects of family planning on fertility behaviour across the demographic transition . Scientific Reports. Vol. 11(1), 1-12. Published, 04/01/2021.
    https://doi.org/10.1038/s41598-021-86180-8
  • Jones, J.H. & Jones, J.H., A Pisor, KG Douglass, R Bliege Bird, E Ready, A Hazel &, J Hackman, KL Kramer, TA Kohler, H Pontzer, MC Towner (2021) How can evolutionary and biological anthropologists engage broader audiences. American Journal of Human Biology, invited iss (2021). How can evolutionary and biological anthropologists engage broader audiences . American Journal of Human Biology, invited issue on Climate Change. Vol. doi.org/10.1002/ajhb.23592. Accepted, 02/26/2021.
  • Shattuck-Heidorn, H. & Eick, G, KL Kramer, LS Sugiyama, JJ Snodgrass & PT Ellison (2020). Variability of C-reactive protein in a first-generation Ecuadorian immigrant population living in the U.S. American Journal of Human Biology. Vol. D1, Dec 1:e23547. Published, 12/01/2020.
  • Kramer, KL (2020). Childhood teaching and learning among Savanna Pumé hunter-gatherers. Mismatch between traditional foraging and modern industrialized societies. 32(1) . Human Nature, special issue on Teaching & Learning in Foraging & Transitioning Populations. Vol. doi 0.1007/s12110-021-09392-x. Accepted, 08/30/2020.
  • Kramer, KL & J Hackman (2020). Scaling climate change to human behavior. Predicting good years and bad years for Maya farmers . American Journal of Human Biology. Vol. 33, e23524. Published, 08/26/2020.
  • Kramer, KL (2020). Why are there so many humans? . [Website/Blog]. Published, 06/09/2020.
  • Koster, J & R McElreath, M Alvard, S Beckerman, D Bird, R Bliege Bird, L Coad, B Codding, R Duda, R Ellen, K Endicott, A Fernandez-Llamazares, M Franzen, S Gallois, R Greaves, M Gueze, M Gurven, T Headland, C Healey, K Hill, T Kraft, KL Kramer, K Lupo, S Marks, L Nap (2020). The life history of human foraging: cross-cultural and individual variation . Science Advances. Vol. 6(26), eaax9070. Published, 01/08/2020.
  • Veile, A. & S Asaf, E Otárola-Castillo & KL Kramer (2019). Hydration, lactation, and child health outcomes in Yucatec Maya . Springer Nature. Published, 12/01/2019.
  • Borgerhoff Mulder, M, & MC Towner, R Baldini, BA Beheim, H Colleran, M Gurven, KL Kramer, SL Mattison, DA Nolin, B Scelza, R Sear, M Shenk, E Voland & J Ziker (2019). Differences between sons and daughters in the intergenerational transmission of wealth. Philosophical Transactions of the Royal Society B: Biological Sciences,. Vol. 374(1780): 20180076. Published, 11/01/2019.
  • Koster, J, & D Lukas, D Nolin, E Power, A Alvergne, R Mace, C Ross, KL Kramer, RD Greaves, M Caudell, S MacFarlan, E Schniter, R Quinlan, S Mattison, A Reynolds, C Yi-Sum & E Massengill (2019). Kinship ties across the lifespan in human communities. Philosophical Transactions of the Royal Society B, Biological Sciences. Vol. 374(1780), 20180069. Published, 04/01/2019.
  • Šaffa, G, & AM Kubicka, M Hromada & KL Kramer (2019). Is the timing of menarche correlated with mortality and fertility rates? , . PLoS One. Vol. 14(4):, e0215462. Published, 03/08/2019.
  • Kramer, KL (2019). How there got to be so many of us. The evolutionary story of population growth and a life history of cooperation . Journal of Anthropological Research. Vol. 75(4):, 472-497. Published, 03/08/2019.
  • Schacht, RS & & KL Kramer (2019). Are we monogamous? A review of the evolution of pair-bonding and its contemporary variation cross-culturally . Frontiers in Ecology and Evolution. Vol. 7:230 doi: 10.3389/fevo.2019.0. Published, 03/01/2019.
  • Veile, A. (2019) & C Valeggia & KL Kramer (2019). Cesarean birth and the growth of Yucatec Maya and Toba/Qom children. American Journal of Human Biology. Vol. e23228, 1-14. Published, 02/01/2019.
  • Veile, A. & A Faria, S Rivera, SM Tuller & KL Kramer (2019). Birth mode, breastfeeding and childhood infectious morbidity in the Yucatec Maya. American Journal of Human Biology. Vol. e23218, 1-12. Published, 01/15/2019.
  • Schacht, R.S. , HE Davis, KL Kramer & KL Kramer (2018). Patterning of paternal investment in response to socioecological change. Frontiers in Ecology and Evolution. Vol. 6(142), 1-12. Published, 12/01/2018.
  • Ross, C, & M Borgerhoff Mulder and others (2018). Greater wealth inequality, less polygyny: Rethinking the polygyny threshold model. Journal of Royal Society Interface. Vol. 15(144), 20180035 DOI:10.1098/r. Published, 07/2018.
  • Veile, A. & Kramer, KL (2018). Pregnancy, birth and babies: motherhood and modernization in a Yucatec village. In Maternal Health, Pregnancy-Related Morbidity and Death among Indigenous Women of Mexico & Central America . (pp. 205-224). Springer Nature. Published, 06/01/2018.
  • Kramer, KL & A Veile (2018). Infant allocare in traditional societies. Physiology and Behavior. Vol. 193(A), 117-126. Published, 02/28/2018.
    http://communications.elsevier.com/r/?id=h68fcebc8...
  • Kramer, KL (2018). The cooperative economy of food. Implications for human life history and physiology. Physiology and Behavior. Vol. 193, 196-204. Published, 02/01/2018.
    http://communications.elsevier.com/r/?id=h6d19d6b7...
  • Urlacher, SS & KL Kramer (2018). Evidence for energetic tradeoffs between physical activity and childhood growth across the nutritional transition. Scientific Reports DOI:10.1038/s41598-017-18738-41/10/2018. Vol. 8:369, 1-10. Published, 01/10/2018.
  • Veile, A & KL Kramer (2018). Shifting weanling’s optimum: breastfeeding ecology and infant health in Yucatan. In Breastfeeding New Anthropological Approaches . (pp. 170-184). Routledge Press, London. Published, 01/01/2018.
  • Schacht, R, KL Kramer, T Szekely and P Kappeler, eds (2017) Adult Sex Ratios and Reproductive Strategies: A Critical Re-examination of Sex Differences in Human and Animal societies. Philosophical Transactions, B 372 (1729) ISSN 0962-8436. Published, 07/2017.
  • Kramer, KL, R Schacht & A Bell (2017) Adult sex ratios & partner scarcity among hunter-gatherers: implications for dispersal patterns and the evolution of human sociality. Philosophical Transactions of the Royal Society, B 372 20160316 http://dx.doi.org/10.1098/rstb.2016.0316. Published, 07/2017.
  • Schacht, R, KL Kramer, T Székely & P Kappeler (2017) Adult sex ratios and reproductive decisions: a critical reexamination of sex differences in human and animal societies. Philosophical Transactions, B 372 20160309 http://dx.doi.org/10.1098/rstb.2016.0309. Published, 07/2017.
  • AV Jaeggi*, KL Kramer*, R Hames*, EJ Kiely, C Gomes, H Kaplan & M Gurven (2017) Human grooming in comparative perspective: People in six small-scale societies groom less but socialize just as much as expected for a typical primate. American Journal of Physical Anthropology DOI: 10.1002/ajpa.23164. * authors contributed equally to this work. Published, 01/18/2017.
  • Veile, A & KL Kramer (2016) Childhood body size is positively associated with cesarean birth in Yucatec Maya subsistence farmers. American Journal of Human Biology, Oct 4, 2016. DOI: 10.1002/ajhb.22920. Published, 10/04/2016.
  • Lancelotti, C, D Zurro, NJ Whitehouse, KL Kramer, M Madella, JJ García-Granero, RD Greaves (2016) Resilience of small-scale societies’ livelihoods: a framework for studying the transition from food gathering to food production. Ecology & Society 21(4):8. DOI: http://dx.doi.org /10.5751/ES-08757-210408. Published, 10/2016.
  • Schacht, R & KL Kramer (2016) Patterns of family formation in response to sex ratio. PLoS ONE 11(8): e0160320. doi:10.1371/journal.pone.0160320. Published, 08/24/2016.
    http://journals.plos.org/plosone/article?id=10.137...
  • Codding, BF & KL Kramer, eds (2016) Why Forage? Hunters and Gatherers Living in the 21st Century. School of Advanced Research, Santa Fe. https://unmpress.com/books.php?ID=20000000007067. Published, 05/31/2016.
  • Kramer, KL & B Codding (2016) Hunter-Gatherers in the 21st century. In Why Forage? Hunters and Gatherers Living in the 21st Century, B Codding & KL Kramer (eds). School of Advanced Research & UNM Press, Albuquerque. Published, 05/01/2016.
  • Kramer, KL & RD Greaves (2016) Diversity or Replace. What happens to wild foods when cultigens are introduced into hunter-gatherer diets. In Why Forage? Hunters and Gatherers Living in the 21st Century, B Codding & KL Kramer (eds). School of Advanced Research & UNM Press, Albuquerque. Published, 05/01/2016.
  • Kramer, KL, A Veile & E Otárola-Castillo (2016) Sibling competition, growth tradeoffs. Biological vs. statistical significance. PLoS ONE 11(3): e0150126. doi:10.1371/journal.pone.0150126. Published, 03/03/2016.
    http://journals.plos.org/plosone/article?id=10.137...
  • E Cashdan, Kramer, KL, HE Davis, RD Greaves & L Padilla (2016) Mobility and navigation among the Yucatec Maya. Sex differences reflect parental investment, not mating competition. Human Nature 27:35-50. Published, 01/2016.
    http://link.springer.com/article/10.1007%2Fs12110-...
  • Blake, PR, K McAuliffe, T Callaghan, J Corbit, O Barry, A Bowie, L Kleutsch, KL Kramer, E Ross, H Vongsachang, R Wrangham, & F Warneken (2015) The ontogeny of fairness in seven cultures cultures. Nature 528:258-261. Published, 10/01/2015.
  • Kramer, KL & E Otárola-Castillo (2015) When mothers need others. Life history transitions associated with the evolution of cooperative breeding. Journal of Human Evolution 84:16-24. Published, 05/2015.
    http://www.sciencedirect.com/science/article/pii/S...
  • Kramer, KL & AF Russell (2015) Was monogamy a key step on the hominin road? Reevaluation of the Monogamy Hypothesis. Evolutionary Anthropology 24:73-83. Published, 03/2015.
    http://onlinelibrary.wiley.com/doi/10.1002/evan.21...
  • Kramer, KL (2015) Cooperative breeding & human evolution. In Emerging Trends in the Social and Behavioral Sciences, RA Scott & SM Kosslyn (eds). John Wiley and Sons, Hoboken, NJ. DOI:10.1002/9781118900772.etrds0055. Published, 01/01/2015.
    http://onlinelibrary.wiley.com/doi/10.1002/9781118...
  • Kramer, KL and AF Russell (2014) Kin-selected cooperation without lifetime monogamy: human insights and animal implications. Trends in Ecology & Evolution 29(11):600-606. Published, 11/01/2014.
    http://www.sciencedirect.com/science/article/pii/S...
  • Greaves, RD and KL Kramer (2013) Hunter-gatherer use of wild plants and domesticates: archaeological implications for mixed economies before agricultural intensification. Journal of Archaeological Science 41:263-271. Published, 09/2013.
    http://www.sciencedirect.com/science/article/pii/S...
  • Kramer, KL (2014) Why what juveniles do matters in the evolution of cooperative breeding. Human Nature, special edition on eusociality, 25(1):49-65. Published, 06/2013.
    http://link.springer.com/article/10.1007/s12110-01...
  • Veile, A, J Winking, RD Greaves, M Gurven & KL Kramer (2012) Infant growth and the thymus: data from two South American native societies. American Journal of Human Biology 24(6):768-775. Published, 01/2012.
    http://onlinelibrary.wiley.com/doi/10.1002/ajhb.22...
  • Kramer, KL (2011) The evolution of human parental care and recruitment of juvenile help. Trends in Ecology and Evolution 26(10):533-540. Published, 10/2011.
    http://ac.els-cdn.com/S0169534711001650/1-s2.0-S01...
  • Kramer, KL & PT Ellison (2010) Pooled energy budgets: Resituating human energy allocation tradeoffs. Evolutionary Anthropology 19:136-147. Published, 10/2010.
    http://onlinelibrary.wiley.com/doi/10.1002/evan.20...
  • Kramer, KL (2010) Cooperative breeding and its significance to the demographic success of humans. Annual Review of Anthropology 39:414-436. Published, 10/2010.
    http://www.annualreviews.org/doi/abs/10.1146/annur...
  • Kramer, KL & JB Lancaster (2010) Teen motherhood in cross-cultural perspective. Annals of Human Biology 37(5):613-628. Published, 10/2010.
    http://www.tandfonline.com/doi/abs/10.3109/0301446...
  • Kramer, KL, RD Greaves & PT Ellison (2009) Early reproductive maturity among Pumé foragers. Implications of a pooled energy model to fast life histories. American Journal of Human Biology 21(4): 430-437. Published, 10/2009.
    http://www.fas.harvard.edu/~bioanth/pdf/AJHB_2009....
  • Kramer, KL (2008) Early sexual maturity among Pumé foragers of Venezuela: Fitness implications of teen motherhood. American Journal of Physical Anthropology 136 (3): 338-350. Published, 05/2008.
    http://onlinelibrary.wiley.com/doi/10.1002/ajpa.20...
  • Kramer, KL (2005) Maya Children: Helpers at the Farm. Harvard University Press, Cambridge. Published, 05/2005.
    https://books.google.com/books?hl=en&lr=&id=-qMlJO...

Research Keywords

  • life history, cooperation, cooperative breeding, evolution of childhood, behavioral ecology, hunter-gatherers

Presentations

  • Hunting hypothesis and male-centered myths in Anthropology, CARTA symposium, Salk Institute for Biological Studies, UCSD, La Jolla. Invited Talk/Keynote, Accepted, 02/2023.
  • Living on an Uncertain Landscape. Fertility and Livelihood Responses to Market Integration & Climate Change. Plenary session, Human Biology Association, Denver. Invited Talk/Keynote, Presented, 03/23/2022.
  • Variation in Adolescent Sleep: Sleeping Behaviour among Mayan Juveniles. 1st author A Silva-Caballero. Human Biology Association, Los Angeles. Conference Paper, Refereed, Accepted, 04/18/2020.
  • Fertility Variance Not Decline Characterizes the Early Demographic Transition. Population Association Of American, Denver (scheduled). Conference Paper, Presented, 03/15/2018.
  • The Cooperative Economy of food in Traditional Societies: Its Effect on Human Life History & Physiology. IBRC, Purdue University. Invited Talk/Keynote, Presented, 10/03/2017.
  • Mating Competition, Mobility, and Wayfinding: A Comparison of Three Societies, (1st author E Cashdan). HBES, Boise. Conference Paper, Presented, 07/01/2017.
  • Too Many Men? Too Many Women? Effects of Sex-Ratio Imbalance on Marriage and Family Formation, (1st author R Schacht). Population Association of America, Chicago. Conference Paper, Presented, 04/28/2017.
  • Child Physical Activity during the Economic Transition among Small-Scale Populations, (1st author SS Urlacher). Population Association of America, Chicago. Conference Paper, Presented, 04/28/2017.
  • Objectively Measured Childhood Physical Activity among Small-Scale Populations, (1st author SS Urlacher). American Association of Physical Anthropologists, New Orleans. Conference Paper, Presented, 04/21/2017.
  • Sex Ratio Imbalance Affects Marriage and Reproductive Decisions among Pumé Hunter-Gatherers. American Association of Physical Anthropologists, New Orleans. Conference Paper, Presented, 04/20/2017.
  • Seasonal Fluctuation in Body Fat Sexual Dimorphism among Pumé Hunter-Gatherers, (1st author A Achenbach). American Association of Physical Anthropologists, New Orleans. Poster, Presented, 04/20/2017.
  • Cesarean Births Modulate Indigenous Children’s Growth in Rural and Urban Settings, (1st author A Veile). Human Biology Association, New Orleans. Conference Paper, Presented, 04/17/2017.
  • Continued Hunter-Gatherer Independence in an Inhospitable Environment and Troubled Economy: Savanna Pumé Foragers of the Venezuelan Llanos, (1st author RD Greaves). Society for Applied Anthropology, Santa Fe. Conference Paper, Presented, 03/21/2017.

Research Groups

  • Karen L Kramer, Research Professor. Santa Fe Institute, University of Cinncinate. 02/15/2017 - 12/31/2025.
  • The Effects of Social Networks on Inequality , Other. 01/01/2017 - 12/31/2017. Awards/Scholarships/Stipends: 0.
  • The Effects of Social Networks on Inequality , Other. Santa Fe Institute. 08/2016 - present.
  • Polygyny Paradox Project , Other. 01/2014 - present.
  • Dynamics of Wealth Inequality , Other. Santa Fe Institute. 02/01/2012 - present.

Grants, Contracts & Research Gifts

  • Currently funded research: Emerging Differences in Children’s Economic Roles and Parental Investment though the Fertility Transition of Maya Farmers. PI: Kramer. National Science Foundation, 08/01/2010 - present. Total project budget to date: $270,898.00
  • Risk Sensitive Decision Making among Maya Farmers: Subsistence diversification in Response to Novel Environments. PI: KL Kramer. Co-PI(s): R Schacht. National Science Foundation,, 07/01/2016 - 07/01/2019. Total project budget to date: $324,431.00
  • Spatial Reasoning among Maya Children: An Interdisciplinary and Cross-Cultural Study. PI: KL Kramer. University of Utah Interdisciplinary Research Pilot Program , 08/01/2015 - 07/31/2016. Total project budget to date: $10,000.00

Geographical Regions of Interest

  • Americas
    Mexico, South America, Madagascar & Small-scale societies everywhere.