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This study tests two evolutionary hypotheses on grandparental investments differentiated by the child's sex: the paternity uncertainty hypothesis and the Trivers–Willard hypothesis. Data are from two culturally different countries: the Dutch Longitudinal Aging Study Amsterdam (n=2375) and the Chinese Anhui Survey (n=4026). In the Netherlands, grandparental investments are biased towards daughters' children, which is in accordance with the paternity uncertainty hypothesis. But in China, grandparental investments are biased towards sons' children, which is in conflict with the paternity uncertainty hypothesis. This study found no support for the Trivers–Willard hypothesis. These results raise doubts over the relevance of paternity uncertainty as an explanation of a grandparental investment bias towards daughters' children that is often found in Western populations. The results suggest that discriminative grandparental investments are better understood as the outcome of cultural prescriptions and economic motives.

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Almond, D. & Edlund, L. (2007) Trivers–Willard at birth and one year: evidence from US natality data 1983–2001. Proceedings of the Royal Society B: Biological Sciences 274, 24912496.
Alvergne, A., Faurie, C. & Raymond, M. (2009) Father–offspring resemblance predicts paternal investment in humans. Animal Behaviour 78, 6169.
Anderson, K. G. (2006) How well does paternity confidence match actual paternity? Evidence from worldwide nonpaternity rates. Current Anthropology 47, 513520.
Anderson, K. G., Kaplan, H. & Lancaster, J. B. (2007) Confidence of paternity, divorce, and investment in children by Albuquerque men. Evolution and Human Behavior 28, 110.
Bishop, D. I., Meyer, B. C., Schmidt, T. M. & Gray, B. R. (2009) Differential investment behavior between grandparents and grandchildren: the role of paternity uncertainty. Evolutionary Psychology 7, 6677.
Boerner, K. & Reinhardt, J. P. (2003) Giving while in need: support provided by disabled older adults. Journal of Gerontology: Social Sciences 58B, S297304.
Boyd, R. & Richerson, P. J. (2009) Culture and the evolution of human cooperation. Philosophical Transactions of the Royal Society B: Biological Sciences 364, 32813288.
Boyd, R., Richerson, P. J. & Henrich, J. (2011) The cultural niche: why social learning is essential for human adaptation. Proceedings of the National Academy of Sciences of the USA 108, 1091810925.
Brown, G. R., Laland, K. N. & Borgerhoff Mulder, M. (2009) Bateman's principles and human sex roles. Trends in Ecology & Evolution 24, 297304.
Buss, D. M. (1994) The Evolution of Desire: Strategies of Human Mating. Basic Books, New York.
Buss, D. M. & Schmitt, D. P. (1993) Sexual strategies theory: an evolutionary perspective on human mating. Psychological Review 100, 204232.
Cameron, E. Z. & Dalerum, F. (2009) A Trivers–Willard effect in contemporary humans: male-biased sex ratios among billionaires. PLoS ONE 4, 14.
Cardia, E. & Ng, S. (2003) Intergenerational time transfers and childcare. Review of Economic Dynamics 6, 431454.
Chrastil, E. R., Getz, W. M., Euler, H. A. & Starks, P. T. (2006) Paternity uncertainty overrides sex chromosome selection for preferential grandparenting. Evolution and Human Behavior 27, 206223.
Coall, D. A. & Hertwig, R. (2010) Grandparental investment: past, present, and future. Behavioral and Brain Sciences 33, 119.
Deeg, D. J. H., Van Tilburg, T., Smit, J. H. & De Leeuw, E. D. (2002) Attrition in the Longitudinal Aging Study Amsterdam: the effect of differential inclusion in side studies. Journal of Clinical Epidemiology 55, 319328.
Dimova, R. & Wolff, F. (2011) Do downward private transfers enhance maternal labor supply? Evidence from around Europe. Journal of Population Economics 24, 911933.
Draper, D. (2008) Bayesian multilevel analysis and MCMC. In De Leeuw, J. & Meijer, E. (eds) Handbook of Multilevel Analysis. Springer, New York, pp. 77139.
Dubas, J. S. (2001) How gender moderates the grandparent–grandchild relationship: a comparison of kin-keeper and kin-selector theories. Journal of Family Issues 22, 478492.
Eisenberg, A. R. (1988) Grandchildren's perspectives on relationships with grandparents: the influence of gender across generations. Sex Roles 19, 205217.
Euler, H. A., Hoier, S. & Rohde, P. A. (2001) Relationship-specific closeness of intergenerational family ties: findings from evolutionary psychology and implications for models of cultural transmission. Journal of Cross-Cultural Psychology 32, 147158.
Euler, H. A. & Weitzel, B. (1996) Discriminative grandparental solicitude as reproductive strategy. Human Nature 7, 3959.
Fieder, M. & Huber, S. (2007) The effects of sex and childlessness on the association between status and reproductive output in modern society. Evolution and Human Behavior 28, 392398.
Fieder, M., Huber, S. & Bookstein, F. L. (2011) Socioeconomic status, marital status and childlessness in men and women: an analysis of census data from six countries. Journal of Biosocial Science 43, 619635.
Fingerman, K., Miller, L., Birditt, K. & Zarit, S. (2009) Giving to the good and the needy: parental support of grown children. Journal of Marriage and Family 71, 12201233.
Fox, M., Johow, J. & Knapp, L. A. (2011) The selfish grandma gene: the roles of the X-chromosome and paternity uncertainty in the evolution of grandmothering behavior and longevity. International Journal of Evolutionary Biology 2011, 19.
Fox, M., Sear, R., Beise, J., Ragsdale, G., Voland, E. & Knapp, L. A. (2010) Grandma plays favourites: X-chromosome relatedness and sex-specific childhood mortality. Proceedings of the Royal Society B: Biological Sciences 277, 567573.
Freese, J. & Powell, B. (1999) Sociobiology, status, and parental investment in sons and daughters: testing the Trivers–Willard hypothesis. American Journal of Sociology 104, 17041743.
Friedman, D., Hechter, M. & Kreager, D. (2008) A theory of the value of grandchildren. Rationality and Society 20, 3163.
Fuller-Thomson, E. & Minkler, M. (2001) American grandparents providing extensive child care to their grandchildren: prevalence and profile. Gerontologist 41, 201209.
Gaulin, S. J. C. & Robbins, C. J. (1991) Trivers–Willard effect in contemporary North American society. American Journal of Physical Anthropology 85, 6169.
Geary, D. C. (1998) Male, Female: The Evolution of Human Sex Differences. American Psychological Association, Washington.
Geary, D. C., Vigil, J. & Byrd-Craven, J. (2004) Evolution of human mate choice. Journal of Sex Research 41, 2742.
Geurts, T., Poortman, A-R. & Van Tilburg, T. G. (2012) Older parents providing child care for adult children: does it pay off? Journal of Marriage and Family 74, 239250.
Gilding, M. (2009) Paternity uncertainty and evolutionary psychology: how a seemingly capricious occurrence fails to follow laws of greater generality. Sociology 43, 140157.
Gray, A. (2005) The changing availability of grandparents as carers and its implications for childcare policy in the UK. Journal of Social Policy 34, 557577.
Hank, K. & Buber, I. (2009) Grandparents caring for their grandchildren: findings from the 2004 survey of health, ageing, and retirement in Europe. Journal of Family Issues 30, 5373.
Hawkes, K. (2004) Human longevity: the grandmother effect. Nature 428, 128129.
Heijkoop, M., Dubas, S. & van Aken, M. (2009) Parent–child resemblance and kin investment: physical resemblance or personality similarity? European Journal of Developmental Psychology 6, 6469.
Henretta, J., Hill, M., Li, W., Soldo, B. & Wolf, D. (1997) Selection of children to provide care: the effect of earlier parental transfers. Journals of Gerontology: Psychological and Social Sciences 52, 110119.
Hopcroft, R. L. (2005) Parental status and differential investment in sons and daughters: Trivers–Willard revisited. Social Forces 83, 11111136.
Hopcroft, R. L. (2006) Sex, status, and reproductive success in the contemporary United States. Evolution and Human Behavior 27, 104120.
Hoppmann, C. A. & Klumb, P. L. (2010) Grandparental investment facilitates harmonization of work and family in employed parents: a lifespan psychological perspective. Behavioral and Brain Sciences 33, 2728.
Hox, J. J. (2002) Multilevel Analysis: Techniques and Applications. Lawrence Erlbaum, Mahwah.
Hrdy, S. B. (2005) Cooperative breeders with an ace in the hole. In Voland, E., Chasiotis, A. & Schiefenhövel, W. (eds) Grandmotherhood: The Evolutionary Significance of the Second Half of Female Life. Rutgers University Press, New Brunswick, pp. 295317.
Johnson, J. O. (2005) Who's Minding the Kids? Child Care Arrangements: Winter 2002. US Census Bureau, Washington.
Kaptijn, R. & Thomese, F. (2010) Fitness effects of grandparental investments in contemporary low-risk societies. Behavioral and Brain Sciences 33, 2930.
Kaptijn, R., Thomese, F., Van Tilburg, T. & Liefbroer, A. (2010) How grandparents matter: support for the cooperative breeding hypothesis in a contemporary Dutch population. Human Nature 21, 393405.
Keller, M. C., Nesse, R. M. & Hofferth, S. (2001) The Trivers–Willard hypothesis of parental investment: no effect in the contemporary United States. Evolution and Human Behavior 22, 343360.
King, V. & Elder, G. H. Jr (1995) American children view their grandparents: linked lives across three rural generations. Journal of Marriage and the Family 57, 165178.
King, V., Silverstein, M., Elder, G. H. Jr, Bengtson, V. L. & Conger, R. D. (2003) Relations with grandparents: rural midwest versus urban Southern California. Journal of Family Issues 24, 10441069.
Knipscheer, C. P. M., De Jong Gierveld, J., Van Tilburg, T. & Dykstra, P. A. (eds) (1995) Living Arrangements and Social Networks of Older Adults. VU University Press, Amsterdam.
Kohli, M. & Künemund, H. (2003) Intergenerational transfers in the family: what motivates giving? In Bengtson, V. L. & Lowenstein, A. (eds) Global Aging and Challenges to Families. Aldine de Gruyter, New York, pp. 123142.
Koziel, S. & Ulijaszek, S. J. (2001) Waiting for Trivers and Willard: do the rich really favor sons? American Journal of Physical Anthropology 115, 7179.
Kunemund, H. & Rein, M. (1999) There is more to receiving than needing: theoretical arguments and empirical explorations of crowding in and crowding out. Ageing and Society 19, 93121.
Laham, S. M., Gonsalkorale, K. & Von Hippel, W. (2005) Darwinian grandparenting: preferential investment in more certain kin. Personality and Social Psychology Bulletin 31, 6372.
Lahdenpera, M., Lummaa, V., Helle, S., Tremblay, M. & Russell, A. F. (2004) Fitness benefits of prolonged post-reproductive lifespan in women. Nature 428, 178181.
Lahdenpera, M., Russell, A. F. & Lummaa, V. (2007) Selection for long lifespan in men: benefits of grandfathering? Proceedings of the Royal Society B: Biological Sciences 274, 24372444.
Lai-wan, C. C., Blyth, E. & Hoi-yan, C. C. (2006) Attitudes to and practices regarding sex selection in China. Prenatal Diagnosis 26, 610613.
Liao, T. F. (1994) Interpreting Probability Models: Logit, Probit, and Other Generalized Linear Models. Sage, Thousand Oaks.
McGarry, K. & Schoeni, R. (1997) Transfer behavior within the family: results from the asset and health dynamics study. Journals of Gerontology: Psychological and Social Sciences 52, 8292.
Magnuson, A., Bodin, L. & Montgomery, S. M. (2007) Father's occupation and sex ratio of offspring. Scandinavian Journal of Public Health 35, 454459.
Michalski, R. L. & Shackelford, T. K. (2005) Grandparental investment as a function of relational uncertainty and emotional closeness with parents. Human Nature 16, 293305.
Nettle, D. & Pollet, T. V. (2008) Natural selection on male wealth in humans. The American Naturalist 172, 658666.
Nowak, M. A. (2006) Five rules for the evolution of cooperation. Science 314, 15601563.
Pashos, A. (2000) Does paternal uncertainty explain discriminative grandparental solicitude? A cross-cultural study in Greece and Germany. Evolution and Human Behavior 21, 97109.
Pillemer, K. & Suitor, J. J. (2006) Making choices: a within-family study of caregiver selection. The Gerontologist 46, 439448.
Pollet, T. V., Nelissen, M. & Nettle, D. (2009) Lineage based differences in grandparental investment: evidence from a large British cohort study. Journal of Biosocial Science 41, 355379.
Pollet, T. V., Nettle, D. & Nelissen, M. (2006) Contact frequencies between grandparents and grandchildren in a modern society: estimates of the impact of paternity uncertainty. Journal of Cultural and Evolutionary Psychology 4, 203213.
Pollet, T. V., Nettle, D. & Nelissen, M. (2007) Maternal grandmothers do go the extra mile: factoring distance and lineage into differential contact with children. Evolutionary Psychology 5, 832843.
Portegijs, W., Cloïn, M., Ooms, I. & Eggink, E. (2006) Hoe het werkt met kinderen: Moeders over kinderopvang en werk. Sociaal en Cultureel Planbureau, Den Haag.
Rasbash, J., Steele, F., Browne, W. & Prosser, B. (2004) A User's Guide to MLwiN. Centre for Multilevel Modelling, University of Bristol, Bristol.
Rice, W. R., Gavrilets, S. & Friberg, U. (2010) The evolution of sex-specific grandparental harm. Proceedings of the Royal Society B: Biological Sciences 277, 27272735.
Richerson, P. J. & Boyd, R. (2004) Not by Genes Alone: How Culture Transformed Human Evolution. University of Chicago Press, Chicago.
Salmon, C. A. (1999) On the impact of sex and birth order on contact with kin. Human Nature 10, 183197.
Sear, R. & Mace, R. (2008) Who keeps children alive? A review of the effects of kin on child survival. Evolution and Human Behavior 29, 118.
Silverstein, M. (2007) Do bioevolutionary forces shape intergenerational transfers? Detecting evidence in contemporary survey data. In Booth, A. (ed.) Caring and Exchange Within and Across Generations. Urban Institute Press, Washington, pp. 127144.
Silverstein, M., Conroy, S. J., Wang, H. T., Giarrusso, R. & Bengtson, V. L. (2002) Reciprocity in parent–child relations over the adult life course. Journal of Gerontology: Social Sciences 57B, S313.
Strassmann, B. & Garrard, W. (2011) Alternatives to the grandmother hypothesis. Human Nature 22, 201222.
Suitor, J. J. & Pillemer, K. (2000) Did mom really love you best? Developmental histories, status transitions, and parental favoritism in later life families. Motivation and Emotion 24, 105120.
Suitor, J. J., Pillemer, K. & Sechrist, J. (2006) Within-family differences in mothers' support to adult children. Journal of Gerontology: Social Sciences 61B, S1017.
Suitor, J. J., Sechrist, J. & Pillemer, K. (2007) Within-family differences in mothers' support to adult children in black and white families. Research on Aging 29, 410435.
Tanskanen, A. O., Rotkirch, A. & Danielsbacka, M. (2011) Do grandparents favor granddaughters? Biased grandparental investment in UK. Evolution and Human Behavior 32, 407415.
Tooby, J. & Cosmides, L. (1990) The past explains the present: emotional adaptations and the structure of ancestral environments. Ethology and Sociobiology 11, 375424.
Tooby, J. & Cosmides, L. (1992) The psychological foundations of culture. In Barkow, J., Tooby, J. & Cosmides, L. (eds) The Adapted Mind: Evolutionary Psychology and the Generation of Culture. Oxford University Press, New York, pp. 19136.
Trivers, R. L. (1971) The evolution of reciprocal altruism. The Quarterly Review of Biology 46, 3557.
Trivers, R. L. (1972) Parental investment and sexual selection. In Campbell, B. (ed.) Sexual Selection and the Descent of Man (1871–1971). Aldline Publishing Company, Chicago, pp. 136179.
Trivers, R. L. & Willard, D. E. (1973) Natural-selection of parental ability to vary sex-ratio of offspring. Science 179, 9092.
Tuljapurkar, S. D., Puleston, C. O. & Gurven, M. D. (2007) Why men matter: mating patterns drive evolution of human lifespan. PloS ONE 2, 16.
Uhlenberg, P. (1996) Mortality decline in the twentieth century and supply of kin over the life course. The Gerontologist 36, 681.
Van der Pas, S. & Van Tilburg, T. (2010) The influence of family structure on the contact between older parents and their adult biological children and stepchildren in the Netherlands. Journal of Gerontology: Social Sciences 65B, 236245.
Waynforth, D. (2012) Grandparental investment and reproductive decisions in the longitudinal 1970 British cohort study. Proceedings of the Royal Society B: Biological Sciences 279, 11551160.
Wheelock, J. & Jones, K. (2002) ‘Grandparents are the next best thing’: informal childcare for working parents in urban Britain. Journal of Social Policy 31, 441463.
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