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Why do mothers favor girls and fathers, boys?

A hypothesis and a test of investment disparity

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Abstract

Growing evidence suggests mothers invest more in girls than boys and fathers more in boys than girls. We develop a hypothesis that predicts preference for girls by the parent facing more resource constraints and preference for boys by the parent facing less constraint. We test the hypothesis with panel data from the Tsimane’, a foraging-farming society in the Bolivian Amazon. Tsimane’ mothers face more resource constraints than fathers. As predicted, mother’s wealth protected girl’s BMI, but father’s wealth had weak effects on boy’s BMI. Numerous tests yielded robust results, including those that controlled for fixed effects of child and household.

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References

  • Behrman, J. R. 1997 Intra-Household Distribution and the Family. In Handbook of Population and Family Economics, M. R. Rosenzweig and O. Stark, eds. Pp. 125–187. Amsterdam: Elsevier.

    Google Scholar 

  • 1998 Intra-Household Allocation of Resources: Is There a Gender Bias? In Too Young to Die: Genes or Gender. Pp. 223–242. New York: United Nations, Department of Economic and Social Affairs, Population Division.

    Google Scholar 

  • Bereczkei, T. 2001 Maternal Trade-Off in Treating High-Risk Children. Evolution and Human Behavior 22:197–212.

    Article  Google Scholar 

  • Bereczkei, T., and R. I. M. Dunbar 2002 Helping-at-the-Nest and Sex-Biased Parental Investment in a Hungarian Gypsy Population. Current Anthropology 43:804–809.

    Article  Google Scholar 

  • Bereczkei, T., A. Hofer, and Z. Ivan 2000 Low Birth Weight, Maternal Birth-Spacing Decisions, and Future Reproduction: A Cost-Benefit Analysis. Human Nature 11:183–205.

    Article  Google Scholar 

  • Betzig, L. L., and P. W. Turke 1986 Parental Investment by Sex on Ifaluk. Ethology and Sociobiology 7:29–37.

    Article  Google Scholar 

  • Borgerhoff Mulder, M. 1998 Brothers and Sisters: How Sibling Interactions Affect Optimal Parental Allocations. Human Nature 9:119–162.

    Article  Google Scholar 

  • Brown, G. R., and J. B. Silk 2002 Reconsidering the Null Hypothesis: Is Maternal Rank Associated with Birth Sex Rations in Primate Groups? Proceedings of the National Academy of Sciences 99:11252–11255.

    Article  Google Scholar 

  • Cameron, E. Z. 2004 Facultative Adjustment of Mammalian Sex Ratios in Support of the Trivers-Willard Hypothesis: Evidence for a Mechanism. Proceedings of the Royal Society of London 271:1723–1728.

    Article  Google Scholar 

  • Cronk, L. 1989 Low Socioeconomic Status and Female-Biased Parental Investment: The Mukogodo Example. American Anthropologist 91:414–429.

    Article  Google Scholar 

  • 1991 Preferential Parental Investment in Daughters over Sons. Human Nature 2:387–417.

    Google Scholar 

  • 2000 Female-Biased Parental Investment and Growth Performance in Mukogodo Children. In Adaptation and Human Behavior: An Anthropological Perspective, L. Cronk, N. Chagnon, and W. Irons, eds. Pp. 203–221. New York: Aldine.

    Google Scholar 

  • Dasgupta, P. 1993 An Inquiry into Well-Being and Destitution. Oxford: Clarendon Press.

    Google Scholar 

  • Deaton, A. 1997 The Analysis of Household Surveys: A Microeconometric Approach to Development Policy. Baltimore: Johns Hopkins University Press.

    Google Scholar 

  • Dietz, W. H., and M. C. Bellizzi 1999 Introduction: The Use of Body Mass Index to Assess Obesity in Children. American Journal of Clinical Nutrition 70:s123-s125.

    Google Scholar 

  • Draper, P., and R. Hames 2000 Birth Order, Sibling Investment, and Fertility among Ju/’hoansi (!Kung). Human Nature 11:117–156.

    Article  Google Scholar 

  • Ejrnaes, M., and C. C. Portner 2004 Birth Order and the Intra-Household Allocation of Time and Education. Review of Economics and Statistics 86:1008–1019.

    Article  Google Scholar 

  • Frisancho, R. A. 1990 Anthropometric Standards for the Assessment of Growth and Nutritional Status. Ann Arbor: University of Michigan Press.

    Google Scholar 

  • Garg, A., and J. Morduch 1998 Sibling Rivalry and the Gender Gap: Evidence from Child Health Outcomes in Ghana. Journal of Population Economics 11:471–493.

    Article  Google Scholar 

  • Gaulin, S. J. C., and C. J. Robbins 1991 Trivers-Willard Effect in Contemporary North American Society. American Journal of Physical Anthropology 85:61–69.

    Article  Google Scholar 

  • Godoy, R. A. 2002 The Life-Cycle, Economic, and Ecological Determinants of Spousal Leisure Sharing: Panel Estimations from an Amerindian Society. Human Ecology 39:317–337.

    Article  Google Scholar 

  • Godoy, R. A., H. Overman, J. Demmer, L. Apaza, E. Byron, T. Huanca, W. R. Leonard, E. Pérez, V. Reyes-García, V. Vadez, D. Wilkie, K. McSweeney, A. Cubas, and N. Brokaw 2002 Local Financial Benefits of Rain Forests: Comparative Evidence from Amerindian Societies. Ecological Economics 40:397–409.

    Article  Google Scholar 

  • Haddad, L., and J. Hoddinott 1994 Women’s Income and Boy-Girl Anthropometric Status in the Côte d’Ivoire. World Development 22:543–553.

    Article  Google Scholar 

  • Hansen, D., H. Moller, and J. Olsen 1999 Severe Periconceptional Life Events and the Sex Ratio in Offspring: Follow-up Study Based on Five National Registers. British Medical Journal 319:548–549.

    Google Scholar 

  • Hoddinott, J., and L. Haddad 1995 Does Female Income Share Influence Household Expenditures? Evidence from Côte d’Ivoire. Oxford Bulletin of Economics and Statistics 57:77–96.

    Google Scholar 

  • Hrdy, S.B. 1999 Mother Nature: A History of Mothers, Infants, and Natural Selection. New York: Pantheon Books.

    Google Scholar 

  • Instituto Nacional de Estadística 2003 Bolivia: características sociodemográficas de la población indígena. La Paz: INE.

    Google Scholar 

  • Keller, H. 2002 Gender and Birth Order as Determinants of Parental Behavior. International Journal of Behavioral Development 26:177–184.

    Article  Google Scholar 

  • Koziel, S., and S. J. Ulijaszek 2001 Waiting for Trivers and Willard: Do the Rich Really Favor Sons? American Journal of Physical Anthropology 115:71–79.

    Article  Google Scholar 

  • Leonard, W. R. 1991 Age and Sex Differences in the Impact of Seasonal Energy Stress among Andean Agriculturalists. Human Ecology 19:351–368.

    Article  Google Scholar 

  • Lohman, T. G., A. F. Roche, and R. Martorell 1988 Anthropometric Standardization Reference Manual, abridged ed. Windsor, Ontario: Human Kinetics.

    Google Scholar 

  • Lundberg, S., and E. Rose 2002 The Effects of Sons and Daughters on Men’s Labor Supply and Wages. Review of Economics and Statistics 84:251–268.

    Article  Google Scholar 

  • Mace, R. 1996 Biased Parental Investment and Reproductive Success in Gabbra Pastoralists. Behavioral Ecology and Sociobiology 38:75–81.

    Article  Google Scholar 

  • McDade, T. W., W. R. Leonard, J. Burhop, V. Reyes-García, V. Vadez, T. Huanca, and R. A. Godoy 2005 Predictors of C-Reactive Protein in Tsimane’ 2-to 15-Year-Olds in Lowland Bolivia. American Journal of Physical Anthropology, 128:906–913.

    Article  Google Scholar 

  • McDowell, N. 1991 The Mundugumor: From the Field Notes of Margaret Mead and Reo Fortune. Washington, D.C.: Smithsonian Institution Press.

    Google Scholar 

  • Mirrlees, J. 1976 A Pure Theory of Underdeveloped Economies. In Agriculture in Development Theory, L. Reynolds, ed. Pp. 235–254. New Haven: Yale University Press.

    Google Scholar 

  • Mott, F. L. 1994 Sons, Daughters and Fathers’ Absence: Differentials in Father-Leaving Probabilities and in Home Environments. Journal of Family Issues 15:97–128.

    Article  Google Scholar 

  • Pitt, M., M. Rosenzweig, and M. N. Hassan 1990 Productivity, Health, and Inequality in the Intra-Household Distribution of Food in Low-Income Countries. American Economic Review 80:1139–1156.

    Google Scholar 

  • Quisumbing, A. R. 1994 Intergenerational Transfer in Philippine Rice Villages: Gender Differences in Traditional Inheritance Customs. Journal of Development Economics 43:167–196.

    Article  Google Scholar 

  • Ray, D. 1998 Development Economics. Princeton: Princeton University Press.

    Google Scholar 

  • Salmon, C. A. 2003 Birth Order and Relationships: Family, Friends, and Sexual Partners. Human Nature 14:73–88.

    Google Scholar 

  • Sieff, D. 1990 Explaining Biased Sex Ratios in Human Populations: A Critique of Recent Studies. Current Anthropology 31:25–35.

    Article  Google Scholar 

  • Stiglitz, J. 1976 The Efficiency Wage Hypothesis, Surplus Labor, and the Distribution of Income in LDCs. Oxford Economic Papers 28:185–207.

    Google Scholar 

  • Tanner, S., V. Reyes-García, V. Vadez, T. Huanca, W. R. Leonard, T. R. McDade, R. Godoy, M. O. Aiello, and K. Hicks 2004 Anthropometrics and Gastrointestinal Parasitic Infections among the Tsimane’ of Bolivia (abstract). American Journal of Human Biology 16:227.

    Google Scholar 

  • Thomas, D. 1994 Like Father, Like Son: Like Mother, Like Daughter. Journal of Human Resources 29:950–988.

    Article  Google Scholar 

  • Trivers, R., and D. E. Willard 1973 Natural Selection of Parental Ability to Vary the Sex Ratio of Offspring. Science 179:90–92.

    Article  Google Scholar 

  • Voland, E. 1984 Human Sex-Ratio Manipulation: Historical Data from a German Parish. Journal of Human Evolution 13:99–107.

    Article  Google Scholar 

  • Weinberg, M. K., E. Z. Tronick, and J. F. Cohn 1999 Gender Differences in Emotional Expressivity and Self-Regulation during Early Infancy. Developmental Psychology 35:175–188.

    Article  Google Scholar 

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Authors and Affiliations

  1. Sustainable International Development Program, MS 078, Heller School for Social Policy and Management, Brandeis University, 02254-9110, Waltham, MA

    Ricardo Godoy & Victoria Reyes-García

  2. Northwestern University, USA

    Thomas McDade

  3. University of Michigan, USA

    Susan Tanner

  4. Northwestern University, USA

    William R. Leonard

  5. Brandeis University, USA

    Tomás Huanca, Vincent Vadez & Karishma Patel

Authors
  1. Ricardo Godoy
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  2. Victoria Reyes-García
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  3. Thomas McDade
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  4. Susan Tanner
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  5. William R. Leonard
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  6. Tomás Huanca
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  7. Vincent Vadez
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  8. Karishma Patel
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Corresponding author

Correspondence to Ricardo Godoy.

Additional information

The National Science Foundation (SBR-9731240 and SBR-9904318) funded the research. Thanks go to L. Apaza, E. Conde, J. D. vila, H. Rivas, P. Pache, E. Tayo, S. Cari, J. Cari, M. Roca, D. Pache, J. Pache, and V. Cuata for help collecting data and logistical support. Thanks to M. Gurven and R. Trivers for references on parental discrimination in evolutionary biology, to J. Behrman and J. Hoddinott for suggestions on the econometric analysis, and to R. Trivers, L. Cronk, E. Byron, M. Borgerhoff Mulder, and three anonymous reviewers for comments on earlier versions.

Godoy, Huanca, and Reyes-García are cultural anthropologists affiliated with the Heller School for Social Policy and Management, Brandeis University. Leonard, McDade, and Tanner are biological anthropologists at Northwestern (Leonard and McDade) and the University of Michigan (Tanner). Vadez is an agronomist with ICRISAT. Patel works in a political polling firm in Washington. They have worked together among the Tsimane’, collecting and analyzing panel data to assess the effects of lifestyle changes on farming systems and natural resources (Huanca, Vadez), folk knowledge (Reyes-García), and health and nutritional status (Leonard, McDade, and Tanner).

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Godoy, R., Reyes-García, V., McDade, T. et al. Why do mothers favor girls and fathers, boys?. Hum Nat 17, 169–189 (2006). https://doi.org/10.1007/s12110-006-1016-9

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  • DOI: https://doi.org/10.1007/s12110-006-1016-9

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