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Grandparental investment: Past, present, and future

Published online by Cambridge University Press:  09 April 2010

David A. Coall  and
Ralph Hertwig
David A. Coall
Affiliation:
School of Psychiatry and Clinical Neurosciences, University of Western Australia, Fremantle, Western Australia 6160, Australia. [email protected]://www.uwa.edu.au/people/david.coall
Ralph Hertwig
Affiliation:
Department of Psychology, University of Basel, 4055 Basel, Switzerland. [email protected]://www.psycho.unibas.ch/hertwig
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Abstract

What motivates grandparents to their altruism? We review answers from evolutionary theory, sociology, and economics. Sometimes in direct conflict with each other, these accounts of grandparental investment exist side-by-side, with little or no theoretical integration. They all account for some of the data, and none account for all of it. We call for a more comprehensive theoretical framework of grandparental investment that addresses its proximate and ultimate causes, and its variability due to lineage, values, norms, institutions (e.g., inheritance laws), and social welfare regimes. This framework needs to take into account that the demographic shift to low fecundity and mortality in economically developed countries has profoundly altered basic parameters of grandparental investment. We then turn to the possible impact of grandparental acts of altruism, and examine whether benefits of grandparental care in industrialized societies may manifest in terms of less tangible dimensions, such as the grandchildren's cognitive and verbal ability, mental health, and well-being. Although grandparents in industrialized societies continue to invest substantial amounts of time and money in their grandchildren, we find a paucity of studies investigating the influence that this investment has on grandchildren in low-risk family contexts. Under circumstances of duress – for example, teenage pregnancy or maternal depression – there is converging evidence that grandparents can provide support that helps to safeguard their children and grandchildren against adverse risks. We conclude by discussing the role that grandparents could play in what has been referred to as Europe's demographic suicide.

Keywords

child developmentdemographic transitionempathygrandmother hypothesisgrandparental investmentgrandparental solicitudeintergenerational transferskin altruismmaternal depressionreciprocal altruism
Type
Target Article
Information
Behavioral and Brain Sciences , Volume 33 , Issue 1 , February 2010 , pp. 1 - 19
Copyright
Copyright © Cambridge University Press 2010

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References

Albertini, M., Kohli, M. & Vogel, C. (2007) Intergenerational transfers of time and money in European families: Common patterns – different regimes? Journal of European Social Policy 17:319–34.CrossRefGoogle Scholar
Aldous, J. (1995) New views of grandparents in intergenerational context. Journal of Family Issues 16:104–22.CrossRefGoogle Scholar
Alexander, R. D. (1974) The evolution of social behavior. Annual Review of Ecology and Systematics 5:325–83.CrossRefGoogle Scholar
American Academy of Pediatrics (1997) Breastfeeding and the use of human milk. Pediatrics 100:1035–39.CrossRefGoogle Scholar
Anderson, K. G. (2005) Relatedness and investment in children in South Africa. Human Nature 16:1–31.CrossRefGoogle ScholarPubMed
Anderson, K. G. (2006) How well does paternity confidence match actual paternity? Evidence from worldwide nonpaternity rates. Current Anthropology 47:513–20.CrossRefGoogle Scholar
Anderson, K. G., Kaplan, H. & Lancaster, J. B. (2007) Confidence of paternity, divorce, and investment in children by Albuquerque men. Evolution and Human Behavior 28:1–10.CrossRefGoogle Scholar
Andreoni, J. (1990) Impure altruism and donations to public goods: A theory of warm-glow giving. Economic Journal 100:464–77.CrossRefGoogle Scholar
Apfel, N. H. & Seitz, V. (1991) Four models of adolescent mother–grandmother relationships in Black inner-city families. Family Relations 40:421–29.CrossRefGoogle Scholar
Arias, E. (2006) United States life tables, 2003. National vital statistics reports (Vol. 54, No. 14). National Center for Health Statistics.Google ScholarPubMed
Arrondel, L. & Masson, A. (2006) Altruism, exchange or indirect reciprocity: What do the data on family transfers show? In: Handbook of the economics of giving, altruism and reciprocity, vol. 2: Applications, ed. Kolm, S. C. & Ythier, J. M., pp. 971–1053. Handbooks in Economics 23. North-Holland/ Elsevier.Google Scholar
Atsalis, S. & Margulis, S. W. (2008) Perimenopause and menopause: Documenting life changes in aging female gorillas. Interdisciplinary Topics in Gerontology 36:119–46.CrossRefGoogle ScholarPubMed
Attar-Schwartz, S., Tan, J.-P., Buchanan, A., Flouri, E. & Griggs, J. (2009) Grandparenting and adolescent adjustment in two-parent biological, lone-parent, and step-families. Journal of Family Psychology 23:67–75.CrossRefGoogle ScholarPubMed
Attias-Donfut, C., Ogg, J. & Wolff, F. C. (2005) European patterns of intergenerational financial and time transfers. European Journal of Ageing 2:161–73.CrossRefGoogle ScholarPubMed
Attias-Donfut, C. & Segalen, M. (2002) The construction of grandparenthood. Current Sociology 50:281–94.CrossRefGoogle Scholar
Aubel, J. (2005) Grandmothers: A learning institution. Retrieved December 7, 2007, from: http://www.grandmotherproject.org/Art.GM.JIC_files/GM.TomeFinal.pdf Google Scholar
Aubel, J., Touré, I. & Diagne, M. (2004) Senegalese grandmothers promote improved maternal and child nutrition practices: The guardians of tradition are not averse to change. Social Science and Medicine 59:945–59.CrossRefGoogle Scholar
Austad, S. N. (1994) Menopuase: An evolutionary perspective. Experimental Gerontology 29:255–63.CrossRefGoogle Scholar
Banks, J. W. (2003) Ka'nisténhsera Teiakotíhsnie's. A native community rekindles the tradition of breastfeeding. AWHONN Lifelines 7:340–47.CrossRefGoogle ScholarPubMed
Barrett, L., Dunbar, R. & Lycett, J. (2002) Human evolutionary psychology. Palgrave.Google Scholar
Barro, R. J. (1974) Are government bonds net wealth? Journal of Political Economy 82:1095–17.CrossRefGoogle Scholar
Barry, D. (1984) Babies and other hazards of sex, p. 54. RodaleGoogle Scholar
Bateman, A. J. (1948) Intra-sexual selection in Drosophila . Heredity 2:349–68.CrossRefGoogle ScholarPubMed
Bauer, T. & Strub, S. (2002) Ohne Krippe Grosi stünde Vieles still [Without grandparental daycare, many things would come to a standstill]. Input for “Forum Familienfragen” der Eidgenössischen Koordinationskommission für Familenfragen, Solothurn, Switzerland. Büro für arbeits- und sozialpolitische Studie, Berne, & Swiss National Science Foundation.Google Scholar
Beck, C. T. (2001) Predictors of postpartum depression. An update. Nursing Research 50:275–85.CrossRefGoogle ScholarPubMed
Becker, G. S. (1974) A theory of social interactions. Journal of Political Economy 82:1063–93.CrossRefGoogle Scholar
Becker, G. S. (1991) A treatise on the family. Harvard University Press.CrossRefGoogle Scholar
Becker, G. S. & Tomes, N. (1976) Child endowments and the quantity and quality of children. Journal of Political Economy 84:S143–S162.CrossRefGoogle Scholar
Becker, G. S. & Tomes, N. (1979) An equilibrium theory of the distribution of income and intergenerational mobility. Journal of Political Economy 87:1153–89.CrossRefGoogle Scholar
Bengtson, V. L. (2001) Beyond the nuclear family: The increasing importance of multigenerational bonds. Journal of Marriage and Family 63:1–16.CrossRefGoogle Scholar
Bentley, M. E., Caulfield, L. E., Gross, S. M., Bronner, Y., Jensen, J., Kessler, L. A. & Paige, D. M. (1999) Sources of influence on intention to breastfeed among African-American women at entry to WIC. Journal of Human Lactation 15:27–34.CrossRefGoogle ScholarPubMed
Bentley, M. E., Dee, D. L. & Jensen, J. L. (2003) Breastfeeding among low income, African-American women: Power, beliefs and decision making. Journal of Nutrition 133:305–09.CrossRefGoogle ScholarPubMed
Bernheim, B. D. & Severinov, S. (2000) Bequests as signals: An explanation for the equal division puzzle (NBER Working Paper No. 7791). National Bureau of Economic Research.CrossRefGoogle Scholar
Billari, F.C. & Kohler, H.-P. (2004) Patterns of low and lowest-low fertility in Europe. Population Studies 58:161–76.CrossRefGoogle ScholarPubMed
Billari, F. C., Kohler, H.-P., Andersson, G. & Lundström, H. (2007) Approaching the limit: Long-term trends in late and very late fertility. Population and Development Review 33:149–70.CrossRefGoogle Scholar
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 7:66–77.CrossRefGoogle Scholar
Black, M. M. & Nitz, K. (1996) Grandmother co-residence, parenting, and child development among low income, urban teen mothers. Journal of Adolescent Health 18:218–26.CrossRefGoogle ScholarPubMed
Black, M. M., Papas, M. A., Hussey, J. M., Hunter, W., Dubowitz, H., Kotch, J. B., English, D. & Schneider, M. (2002) Behavior and development of preschool children born to adolescent mothers: Risk and 3-generation households. Pediatrics 109:573–80.CrossRefGoogle ScholarPubMed
Black, M. M., Siegel, E. H., Abel, Y. & Bentley, M. E. (2001) Home and videotape intervention delays early complementary feeding among adolescent mothers. Pediatrics 107(5):e67.CrossRefGoogle ScholarPubMed
Blake, J. (1987) Differential parental investment: Its effects on child quality and status attainment. In: Parenting across the life span: Biosocial dimensions, ed. Lancaster, J. B., Altmann, J., Rossi, A. S. & Sherrod, L. R., pp. 351–75. Aldine de Gruyter.Google Scholar
Blurton Jones, N., Hawkes, K. & O'Connell, J. (2002) Antiquity of postreproductive life: Are there modern impacts on hunter-gatherer postreproductive life spans? American Journal of Human Biology 14:184–205.CrossRefGoogle ScholarPubMed
Bogin, B. (1997) Evolutionary hypotheses for human childhood. Yearbook of Physical Anthropology 40:63–89.3.0.CO;2-8>CrossRefGoogle Scholar
Bogin, B. & Smith, B. H. (1996) Evolution of the human life cycle. American Journal of Human Biology 8:703–16.3.0.CO;2-U>CrossRefGoogle ScholarPubMed
Borgerhoff Mulder, M. (1998) The demographic transition: Are we any closer to an evolutionary explanation? Trends in Ecology and Evolution 13:266–70.CrossRefGoogle Scholar
Borgerhoff Mulder, M. (2007) Hamilton's rule and kin competition: The Kipsigis case. Evolution and Human Behavior 28:299–312.CrossRefGoogle Scholar
Börsch-Supan, A. & Miegel, M., eds. (2001) Pension reform in six countries: What can we learn from each other? Springer.CrossRefGoogle Scholar
Botcheva, L. B. & Feldman, S. S. (2004) Grandparents as family stabilizers during economic hardship in Bulgaria. International Journal of Psychology 39:157–68.CrossRefGoogle Scholar
Brandon, P. D., Heyworth, C. & Griffen, L. (2007) The rise of three-generation households among two-parent and single-parent families. The Household, Income, and Labour Dynamics in Australia (HILDA) Survey. Retrieved November 20, 2007, from: http://melbourneinstitute.com/hilda/conf/conf2007/HILDA%20Conf%20Papers%202007/All%20Papers/Brandon,%20Peter_final%20paper.pdf Google Scholar
Bridges, L. J., Roe, A. E. C., Dunn, J. & O'Connor, T. G. (2007) Children's perspectives on their relationships with grandparents following parental separation: A longitudinal study. Social Development 16:539–54.CrossRefGoogle Scholar
Brosnan, S. F. & de Waal, F. B. M. (2003) Monkeys reject unequal pay. Nature 425:297–99.CrossRefGoogle ScholarPubMed
Brosnan, S. F., Schiff, H. C. & de Waal, F. B. M. (2005) Tolerance for inequity may increase with social closeness in chimpanzees. Proceedings of the Royal Society of London B: Biological Sciences 272:253–58.Google ScholarPubMed
Brown, S. L., Nesse, R. M., Vinokur, A. D. & Smith, D. M. (2003) Providing social support may be more beneficial than receiving it: Results from a prospective study of mortality. Psychological Science 14:320–27.CrossRefGoogle ScholarPubMed
Brown, W. M., Consedine, N. S. & Magai, C. (2005) Altruism relates to health in an ethnically diverse sample of older adults. The Journals of Gerontology. Series B: Psychological Sciences and Social Sciences 60B:P143–52.CrossRefGoogle Scholar
Burkart, J. M., Fehr, E., Efferson, C. & van Schaik, C. P.. (2007) Other-regarding preferences in a non-human primate: Common marmosets provision food altruistically. Proceedings of the National Academy of Sciences USA 104:19762–66.CrossRefGoogle Scholar
Burton, L. M. (1990) Teenage childbearing as an alternative life-course strategy in multigeneration black families. Human Nature 1:123–43.CrossRefGoogle ScholarPubMed
Burton, L. M. (1992) Black grandparents rearing children of drug-addicted parents: Stressors, outcomes, and social service needs. The Gerontologist 32:744–51.CrossRefGoogle ScholarPubMed
Caldwell, J. C., Caldwell, B. K., Caldwell, P., McDonald, P. F. & Schindlmayr, T. (2006) Demographic Transition Theory. Springer.Google Scholar
Cant, M. A. & Johnstone, R. A. (2008) Reproductive conflict and the separation of reproductive generations in humans. Proceedings of the National Academy of Sciences USA 105:5332–36.CrossRefGoogle ScholarPubMed
Cao, H. (2006) Time and financial transfers within and beyond the family. Journal of Family and Economic Issues 27:375–400.CrossRefGoogle Scholar
Caputo, R. K. (1999) Age-condensed and age-gapped families: Coresidency with elderly parents and relatives in a mature women's cohort, 1967–1995. Marriage and Family Review 29:77–95.CrossRefGoogle Scholar
Carey, J. R. & Judge, D. S. (2001) Life span extension in humans is self-reinforcing: A general theory of longevity. Population and Development Review 27:411–36.CrossRefGoogle Scholar
Caro, T. M., Sellen, D. W., Parish, A., Frank, R., Brown, D. M., Voland, E. & Borgerhoff Mulder, M. (1995) Termination of reproduction in nonhuman and human female primates. International Journal of Primatology 16:205–20.CrossRefGoogle Scholar
Caspari, R. & Lee, S.-H. (2004) Older age becomes common late in human evolution. Proceedings of the National Academy of Sciences USA 101:10895–900.CrossRefGoogle ScholarPubMed
Central Intelligence Agency (2009) The World Factbook. Retrieved August 20, 2009 from: https://www.cia.gov/library/publications/the-world-factbook/rankorder/2127rank.html.Google Scholar
Chase-Lansdale, P. L., Brooks-Gunn, J. & Zamsky, E. S. (1994) Young African-American multigenerational families in poverty: Quality of mothering and grandmothering. Child Development 65:373–93.CrossRefGoogle ScholarPubMed
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 27:206–23.CrossRefGoogle Scholar
Cigno, A. (1993) Intergenerational transfers without altruism: Family, market and state. European Journal of Political Economy 9:505–18.CrossRefGoogle Scholar
Cigno, A. (2006) The political economy of intergenerational cooperation. In: Handbook of the economics of giving, altruism and reciprocity, vol. 2: Applications, ed. Kolm, S. C. & Ythier, J. M., pp. 1505–58. Handbooks in Economics 23. North-Holland/Elsevier.Google Scholar
Clutton-Brock, T. H. (1989) Mammalian mating systems. Proceedings of the Royal Society of London B: Biological Sciences 236:339–72.Google ScholarPubMed
Clutton-Brock, T. H. (1991) The evolution of parental care. Princeton University Press.CrossRefGoogle Scholar
Coall, D. A., Meier, M., Hertwig, R., Wänke, M. & Höpflinger, F. (2009) Grandparental investment: The influence of reproductive timing and family size. American Journal of Human Biology 21:455–63.CrossRefGoogle ScholarPubMed
Cohen, A. A. (2004) Female post-reproductive lifespan: A general mammalian trait. Biological Reviews 79:733–50.CrossRefGoogle ScholarPubMed
Cohen, J. (1965) Some statistical issues in psychological research. In: Handbook of clinical psychology, ed. Wolman, B. B., pp. 95–121. McGraw-Hill.Google Scholar
Cohen, J. (1988) Statistical power analysis for the behavioral sciences, 2nd edition. Erlbaum.Google Scholar
Cohen, S. & Wills, T. A. (1985) Stress, social support, and the buffering hypothesis. Psychological Bulletin 98:310–57.CrossRefGoogle ScholarPubMed
Cooney, T. M. & An, J. S. (2006) Women in the middle: Generational position and grandmothers' adjustment to raising grandchildren. Journal of Women and Aging 18(2):3–24.CrossRefGoogle ScholarPubMed
Council of Europe (2005) Recent demographic developments in Europe, 2004. Council of Europe Publishing.Google Scholar
Cox, C. B. (2000) Empowering grandparents raising grandchildren: A training manual for group leaders. Springer.Google Scholar
Cremer, H. & Pestieau, P. (2006) Wealth transfer taxation: A survey of the theoretical literature. In: Handbook of the economics of giving, altruism and reciprocity, vol. 2: Applications, ed. Kolm, S. C. & Ythier, J. M., pp. 1107–34. Handbooks in Economics 23. North-Holland/Elsevier.Google Scholar
Crookston, B. T., Dearden, K. A., Chan, K., Chan, T. & Stoker, D. D. (2007) Buddhist nuns on the move: An innovative approach to improving breastfeeding practices in Cambodia. Maternal and Child Nutrition 3:10–24.CrossRefGoogle ScholarPubMed
Crosnoe, R. & Elder, G. H. (2002) Life course transitions, the generational stake, and grandparent–grandchild relationships. Journal of Marriage and Family 64:1089–96.CrossRefGoogle Scholar
Daly, M. & Wilson, M. (1980) Discriminative parental solicitude: A biological perspective. Journal of Marriage and Family 42:277–88.CrossRefGoogle Scholar
Dawkins, R. (2006) The selfish gene, 30th anniversary edition. Oxford University Press.Google Scholar
Denham, T. E. & Smith, C. W. (1989) The influence of grandparents on grandchildren: A review of the literature and resources. Family Relations 38:345–50.CrossRefGoogle Scholar
Dennis, C. L. (2005) Psychosocial and psychological interventions for prevention of postnatal depression: Systematic review. British Medical Journal 331:15–23.CrossRefGoogle ScholarPubMed
de Quervain, D. J., Fischbacher, U., Treyer, V., Schellhammer, M., Schnyder, U., Buck, A. & Fehr, E. (2004) The neural basis of altruistic punishment. Science 305:1254–58.CrossRefGoogle ScholarPubMed
d'Espaignet, T. D., Measey, M. L., Carnegie, M. A. & Mackerras, D. (2003) Monitoring the “Strong women, strong babies, strong culture program”: The first eight years. Journal of Paediatrics and Child Health 39:668–872.CrossRefGoogle ScholarPubMed
de Waal, F. (2006) Primates and philosophers. How morality evolved. Princeton University Press.CrossRefGoogle Scholar
de Waal, F. B. M. (2008) Putting the altruism back into altruism: The evolution of empathy. Annual Review of Psychology 59:279–300.CrossRefGoogle ScholarPubMed
de Waal, F. B. M., Leimgruber, K. & Greenberg, A. R. (2008) Giving is self-rewarding for monkeys. Proceedings of the National Academy of Sciences USA 105:13685–89.CrossRefGoogle ScholarPubMed
Drew, L. M. & Silverstein, M. (2007) Grandparents' psychological well-being after loss of contact with their grandchildren. Journal of Family Psychology 21:372–79.CrossRefGoogle ScholarPubMed
Drew, L. M. & Smith, P. K. (2002) Implications for grandparents when they lose contact with their grandchildren: Divorce, family feud, and geographical separation. Journal of Mental Health and Aging 8:95–119.Google Scholar
Dubas, J. S. (2001) How gender moderates the grandparent–grandchild relationship: A comparison of kin-keeper and kin-selector theories. Journal of Family Issues 22:478–92.CrossRefGoogle Scholar
Duong, D. V., Lee, A. H. & Binns, W. (2005) Determinants of breast-feeding within the first 6 months post-partum in rural Vietnam. Journal of Paediatrics and Child Health 41:338–43.CrossRefGoogle ScholarPubMed
Economist, The (2009) More or less equal? A special report on the rich [Electronic version of The Economist, April 2, 2009]. Retrieved from: http://www.economist.com/specialreports/displaystory.cfm?story_id=13356650 Google Scholar
Edwards, O. W. (2006) Teachers' perceptions of the emotional and behavioral functioning of children raised by grandparents. Psychology in the Schools 43:565–72.CrossRefGoogle Scholar
Eggebeen, D. J. (1992) Family structure and intergenerational exchanges. Research on Aging 14:427–47.CrossRefGoogle Scholar
Eisenberg, A. R. (1988) Grandchildren's perspectives on relationships with grandparents: The influence of gender across generations. Sex Roles 19:205–17.CrossRefGoogle Scholar
Ekström, A., Widström, A. M. & Nissen, E. (2003) Breastfeeding support from partners and grandmothers: Perceptions of Swedish women. Birth 30:261–66.CrossRefGoogle ScholarPubMed
Ellison, P. T. (1990) Human ovarian function and reproductive ecology: New hypotheses. American Anthropologist 92:933–52.CrossRefGoogle Scholar
Ellison, P. T. (2001) On fertile ground: A natural history of human reproduction. Harvard University Press.Google Scholar
Esbensen, B. A., Østerlind, K. & Hallberg, I. R. (2007) Quality of life of elderly persons with cancer: A 6-month follow-up. Scandinavian Journal of Caring Sciences 21:178–90.CrossRefGoogle ScholarPubMed
Essock-Vitale, S. M. & McGuire, M. T. (1985) Women's lives viewed from an evolutionary perspectives. II. Patterns of helping. Ethology and Sociobiology 6:155–73.CrossRefGoogle Scholar
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 32:147–58.CrossRefGoogle Scholar
Euler, H. A. & Michalski, R. L. (2007) Grandparental and extended kin relationships. In: Family relationships: An evolutionary perspective, ed. Salmon, C. & Shackelford, T. K., pp. 185–204. Oxford University Press.Google Scholar
Euler, H. A. & Weitzel, B. (1996) Discriminative grandparental solicitude as reproductive strategy. Human Nature 7:39–59.CrossRefGoogle ScholarPubMed
Falbo, T. (1991) The impact of grandparents on children's outcomes in China. Marriage and Family Review 16:369–76.CrossRefGoogle Scholar
Fedigan, L. M. & Pavelka, M. S. M. (2001) Is there adaptive value to reproductive termination in Japanese macaques? A test of maternal investment hypotheses. International Journal of Primatology 22:109–25.CrossRefGoogle Scholar
Fehr, E. & Gächter, S. (2002) Altruistic punishment in humans. Nature 415:137–40.CrossRefGoogle ScholarPubMed
Fehr, E. & Schmidt, K. M. (2006) The economics of fairness, reciprocity and altruism: Experimental evidence and new theories. In: Handbook of the economics of giving, altruism and reciprocity, vol. 1: Foundations, ed. Kolm, S. C. & Ythier, J. M., pp. 615–91. Handbooks in Economics 23. North-Holland/Elsevier.Google Scholar
Fergusson, E., Maughan, B. & Golding, J. (2008) Which children receive grandparental care and what effect does it have? Journal of Child Psychology and Psychiatry 49:161–69.CrossRefGoogle Scholar
Finch, J. & Mason, J. (1993) Negotiating family responsibilities. Routledge.Google Scholar
Fisher, J. R. W., Hammarberg, K. & Baker, H. W. G. (2005) Assisted conception is a risk factor for postnatal mood disturbances and early parenting difficulties. Fertility and Sterility 84:426–30.CrossRefGoogle ScholarPubMed
Fisher, R. A. (1930) The genetical theory of natural selection. Clarendon Press.CrossRefGoogle Scholar
Friedman, D., Hechter, M. & Kreager, D. (2008) A theory of the value of grandchildren. Rationality and Society 20(1):31–63.CrossRefGoogle Scholar
Fujiwara, T. & Lee, C. K. (2008) The impact of altruistic behaviors for children and grandchildren on major depression among parents and grandparents in the United States: A prospective study. Journal of Affective Disorders 107:29–36.CrossRefGoogle ScholarPubMed
Fuller-Thomson, E. (2005) Canadian First Nations grandparents raising grandchildren: A portrait in resilience. International Journal of Aging and Human Development 60:331–42.CrossRefGoogle ScholarPubMed
Fuller-Thomson, E. & Minkler, M. (2000) African American grandparents raising grandchildren: A national profile of demographic and health characteristics. Health and Social Work 25:109–18.CrossRefGoogle ScholarPubMed
Gaulin, S. J. C. (1980) Sexual dimorphism in the human post-reproductive life-span: Possible causes. Journal of Human Evolution 9:227–32.CrossRefGoogle Scholar
Gaulin, S. J. C. & Schlegel, A. (1980) Paternal confidence and paternal investment: A cross cultural test of a sociobiological hypothesis. Ethology and Sociobiology 1:301–309.CrossRefGoogle Scholar
Geary, D. C. (2000) Evolution and proximate expression of human parental investment. Psychological Bulletin 126:55–77.CrossRefGoogle Scholar
Gibson, M. A. & Mace, R. (2005) Helpful grandmothers in rural Ethiopia: A study of the effect of kin on child survival and growth. Evolution and Human Behavior 26:469–82.CrossRefGoogle Scholar
Gibson, M. A. & Mace, R. (2006) An energy-saving development initiative increases birth rate and childhood malnutrition in rural Ethiopia. PLoS Medicine 3:e87.CrossRefGoogle ScholarPubMed
Goh, E. C. L. (2009) Grandparents as childcare providers: An in-depth analysis of the case of Xiamen, China. Journal of Aging Studies 23:60–68.CrossRefGoogle Scholar
Gordon, R. A., Chase-Lansdale, P. L. & Brooks-Gunn, J. (2004) Extended households and the life course of young mothers: Understanding the associations using a sample of mothers with premature, low birth weight babies. Child Development 75:1013–38.CrossRefGoogle ScholarPubMed
Grundy, E. & Henretta, J. C. (2006) Between elderly parents and adult children: A new look at the intergenerational care provided by the “sandwich generation”. Ageing and Society 26:707–22.CrossRefGoogle Scholar
Gurven, M. & Kaplan, H. (2007) Longevity among hunter–gatherers: A cross-cultural examination. Population and Development Review 33:321–65.CrossRefGoogle Scholar
Güth, W., Schmittberger, R. & Schwarze, B. (1982) An experimental analysis of ultimatum bargaining. Journal of Economic Behavior and Organization 3:367–88.CrossRefGoogle Scholar
Guzman, L. (1999) The use of grandparents as child care providers. National Survey of Families and Households Working Paper No. 84. Retrieved July 15, 2008, from: http://www.ssc.wisc.edu/cde/nsfhwp/nsfh84.pdf Google Scholar
Guzman, L. (2004) Grandma and grandpa taking care of the kids: Patterns of involvement. Child Trends Research Brief. Retrieved July 15, 2008, from: http://www.childtrends.org/Files/GrandparentsRB.pdf CrossRefGoogle Scholar
Hadley, C. (2004) The costs and benefits of kin: Kin networks and children's health among the Pimbwe of Tanzania. Human Nature 15:377–95.CrossRefGoogle ScholarPubMed
Hagen, E. H. (1999) The functions of postpartum depression. Evolution and Human Behavior 20:325–59.CrossRefGoogle Scholar
Hagen, E. H., Barrett, H. C. & Price, M. E. (2006) Do human parents face a quantity-quality tradeoff?: Evidence from a Shuar community. American Journal of Physical Anthropology 130:405–18.CrossRefGoogle Scholar
Hames, R. B. (1988) The allocation of parental care among the Ye'kwana. In: Human reproductive behavior: A Darwinian perspective, ed. Betzig, L., Borgerhoff Mulder, M. & Turke, P., pp. 237–51. Cambridge University Press.Google Scholar
Hamilton, W. D. (1964) The genetical evolution of social behaviour (I and II). Journal of Theoretical Biology 7:1–52.CrossRefGoogle Scholar
Hamilton, W. D. (1966) The moulding of senescence by natural selection. Journal of Theoretical Biology 12:12–45.CrossRefGoogle ScholarPubMed
Hammarberg, K. & Clarke, V. E. (2005) Reasons for delaying childbearing: A survey of women aged over 35 years seeking assisted reproductive technology. Australian Family Physician 34:187–89.Google ScholarPubMed
Hammer, M. L. A. & Foley, R. A. (1996) Longevity and life history in hominid evolution. Human Evolution 11:61–66.CrossRefGoogle Scholar
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 30:53–73.CrossRefGoogle Scholar
Hartung, J. (1985) Matrilineal inheritance: New theory and analysis. Behavioral and Brain Sciences 8:661–88.CrossRefGoogle Scholar
Hawkes, K., O'Connell, J. F. & Blurton Jones, N. G. (1989) Hardworking Hadza grandmothers. In: Comparative socioecology: The behavioural ecology of humans and other mammals, ed. Standen, V. & Foley, R. A., pp. 341–66. Basil Blackwell.Google Scholar
Hawkes, K., O'Connell, J. F., Blurton Jones, N. G., Alvarez, H. & Charnov, E. L. (1998) Grandmothering, menopause and the evolution of human life histories. Proceedings of the National Academy of Sciences USA 95:1336–39.CrossRefGoogle ScholarPubMed
Hayslip, B. & Kaminski, P. L. (2005) Grandparents raising their grandchildren: A review of the literature and suggestions for practice. The Gerontologist 45:262–69.CrossRefGoogle ScholarPubMed
Healy, M. C. (2000) Perceived acceptance from grandparents and grandchild adjustment. Doctoral dissertation, Department of Psychology, Temple University, Philadelphia. Dissertation Abstracts International, DAI-B 61/10, p. 5565. (AAT 9990320)Google Scholar
Hertwig, R., Davis, J. N. & Sulloway, F. J. (2002) Parental investment: How an equity motive can produce inequality. Psychological Bulletin 128:728–45.CrossRefGoogle ScholarPubMed
Hess, C. R., Papas, M. A. & Black, M. M. (2002) Resilience among African American adolescent mothers: Predictors of positive parenting in early infancy. Journal of Pediatric Psychology 27:619–29.CrossRefGoogle ScholarPubMed
Heywood, E. M. (1999) Custodial grandparents and their grandchildren. The Family Journal 7:367–72.CrossRefGoogle Scholar
Hill, K. (1993) Life history theory and evolutionary anthropology. Evolutionary Anthropology 2:78–88.CrossRefGoogle Scholar
Hill, K. & Hurtado, A. M. (1991) The evolution of premature reproductive senescence and menopause in human females: An evaluation of the “grandmother hypothesis.” Human Nature 2:313–50.CrossRefGoogle ScholarPubMed
Hill, K. & Hurtado, A. M. (1996) Ache life history: The ecology and demography of a foraging people. Aldine de Gruyter.Google Scholar
Hill, T. J. (2006) Grandchild, grandparent, and parent coresidence from 1970 to 1990: Structural factors affecting state patterns. International Journal of Aging and Human Development 62:117–42.CrossRefGoogle ScholarPubMed
Hoddinott, P., Tappin, D. & Wright, C. (2008) Breast feeding. Clinical Review. British Medical Journal 336:881–87.CrossRefGoogle Scholar
Hoff, A. (2007) Patterns of intergenerational support in grandparent–grandchild and parent–child relationships in Germany. Aging and Society 27:643–65.CrossRefGoogle Scholar
Hofferth, S. L. & Anderson, K. G. (2003) Are all dads equal? Biology versus marriage as a basis for paternal investment. Journal of Marriage and Family 65:21332.CrossRefGoogle Scholar
Hoffman, E. (1980) Young adults' relations with their grandparents: An exploratory study. International Journal of Aging and Human Development 10:299–310.CrossRefGoogle Scholar
Hogan, D. P., Eggebeen, D. J. & Clogg, C. C. (1993) The structure of intergenerational exchanges in American families. American Journal of Sociology 98:1428–58.CrossRefGoogle Scholar
Hoorens, S., Gallo, F., Cave, J. A. K. & Grant, J. C. (2007) Can assisted reproductive technologies help to offset population ageing? An assessment of the demographic and economic impact of ART in Denmark and UK. Human Reproduction 22:2471–75.CrossRefGoogle ScholarPubMed
Höpflinger, F., Hummel, C. & Hugentobler, V. (2006) Teenage grandchildren and their grandparents in urban Switzerland. Retrieved March 31, 2006 from: http://www.nfp52.ch/e_dieprojekte.cfm?Projects.Command=detailsandget=13.Google Scholar
Hrdy, S. B. (1981) The woman that never evolved. Harvard University Press.Google Scholar
Hrdy, S. B. (1999) Mother nature: Maternal instincts and how they shape the human species. Pantheon Books.Google Scholar
Hrdy, S. B. (2005a) Comes the Child before Man: How cooperative breeding and prolonged postweaning dependence shaped human potentials. In: Hunter–gatherer childhoods: Evolutionary, developmental and colonial perspective, ed. Hewlett, B. S. & Lamb, M. E., pp. 65–91. Aldine Transaction.Google Scholar
Hrdy, S. B. (2005b) Cooperative breeders with an ace in the hole. In: Grandmotherhood: The evolutionary significance of the second half of female life, ed. Voland, E., Chasiotis, A. & Schiefenhövel, W., pp. 295–317. Rutgers University Press.Google Scholar
Hrdy, S. B. (2009) Mothers and others: The evolutionary origins of mutual understanding. Harvard University Press.Google Scholar
Huber, B. R. & Breedlove, W. L. (2007) Evolutionary theory, kinship, and childbirth in cross-cultural perspective. Cross-Cultural Research 41:196–219.CrossRefGoogle Scholar
Huber, B. R., Linhartova, V., Cope, D. & Lacy, M. (2004) Evolutionary theory and birth-related investment by kin in cross-cultural perspective. World Cultures 15:60–79.Google Scholar
Hughes, M. E., Waite, L. J., LaPierre, T. A. & Luo, Y. (2007) All in the family: The impact of caring for grandchildren on grandparents' health. The Journals of Gerontology. Series B: Psychological Sciences and Social Sciences 62B:S108–S119.CrossRefGoogle Scholar
Hurme, H. (2006) Grandparents as resource factors in the family. In: Socioemotional development and health from adolescence to adulthood, ed. Pulkkinen, L., Kaprio, J. & Rose, R. J.. Cambridge University Press.Google Scholar
Hyun, O. K., Lee, W., Yoo, A. J., Cho, B. H., Miller, B. C., Schvaneveldt, J. D. & Lau, S. (2002) Social support for two generations of new mothers in selected populations in Korea, Hong Kong, and the United States. Journal of Comparative Family Studies 33:515–27.Google Scholar
Ingram, J., Johnson, D. & Greenwood, R. (2002) Breastfeeding in Bristol: Teaching good positioning, and support from fathers and families. Midwifery 18:87–101.CrossRefGoogle ScholarPubMed
Ingram, J., Johnson, D. & Hamid, N. (2003) South Asian grandmothers' influence on breast feeding in Bristol. Midwifery 19:318–27.CrossRefGoogle ScholarPubMed
Ivey, P. K. (2000) Cooperative reproduction in Ituri forest hunter-gatherers: Who cares for Efe infants? Current Anthropology 41:856–66.CrossRefGoogle Scholar
Jamison, C. S., Cornell, L. L., Jamison, P. L. & Nakazato, H. (2002) Are all grandmothers equal? A review and a preliminary test of the “grandmother hypothesis” in Tokugawa Japan. American Journal of Physical Anthropology 119:67–76.CrossRefGoogle Scholar
Jensen, K., Hare, B., Call, J. & Tomasello, M. (2006) What's in it for me? Self-regard precludes altruism and spite in chimpanzees. Proceedings of the Royal Society of London B: Biological Sciences 273:1013–21.Google ScholarPubMed
Johnson, J., Canning, J., Kaneko, T., Pru, J. K. & Tilly, J. L. (2004) Germline stem cells and follicular renewal in the postnatal mammalian ovary. Nature 428:145–50.CrossRefGoogle ScholarPubMed
Jones, K. P., Walker, L. C., Anderson, D., Lacreuse, A., Robson, S. L. & Hawkes, K. (2007) Depletion of ovarian follicles with age in chimpanzees: Similarities to humans. Biology of Reproduction 77:247–51.CrossRefGoogle ScholarPubMed
Joslin, D. & Harrison, R. (2002) Self-reported physical health among older surrogate parents to children orphaned and affected by HIV disease. AIDs Care 14:619–24.CrossRefGoogle ScholarPubMed
Judge, D. S. & Carey, J. R. (2000) Postreproductive life predicted by primate patterns. The Journals of Gerontology. Series A: Biological Sciences and Medical Sciences 55A:B201–B209.CrossRefGoogle Scholar
Kahana, B. & Kahana, E. (1970) Grandparenthood from the perspective of the developing grandchild. Developmental Psychology 3:98–105.CrossRefGoogle Scholar
Kalil, A., Spencer, M. S., Spieker, S. J. & Gilchrist, L. D. (1998) Effects of grandmother coresidence and quality of family relationships on depressive symptoms in adolescent mothers. Family Relations 47:433–41.CrossRefGoogle Scholar
Kalra, S. K. & Molinaro, T. A. (2008) The association of in vitro fertilization and perinatal morbidity. Seminars in Reproductive Medicine 26:423–35.CrossRefGoogle ScholarPubMed
Kaplan, H. (1994) Evolutionary and wealth flows theories of fertility: Empirical tests and new models. Population and Development Review 20(1):753–91.CrossRefGoogle Scholar
Kaplan, H. (1996) A theory of fertility and parental investment in traditional and modern human societies. Yearbook of Physical Anthropology 39:91–135.3.0.CO;2-C>CrossRefGoogle Scholar
Kaplan, H. (1997) The evolution of the human life course. In: Between Zeus and the salmon: The biodemography of longevity, ed. Wachter, K. W. & Finch, C. E., pp. 175–211. National Academy Press.Google Scholar
Kaplan, H., Hill, K., Lancaster, J. & Hurtado, A. M. (2000) A theory of human life history evolution: Diet, intelligence, and longevity. Evolutionary Anthropology 9:156–85.3.0.CO;2-7>CrossRefGoogle Scholar
Kellam, S. G., Ensminger, M. E. & Turner, R. J. (1977) Family structure and the mental health of children: Concurrent and longitudinal community-wide studies. Archives of General Psychiatry 34:1012–22.CrossRefGoogle ScholarPubMed
Kenny, M. E., Blustein, D. L., Chaves, A., Grossman, J. M. & Gallagher, L. A. (2003) The role of perceived barriers and relational support in the educational and vocational lives of urban high school students. Journal of Counseling Psychology 50:142–55.CrossRefGoogle Scholar
Kirkwood, T. B. L. (1977) Evolution of ageing. Nature 270:301–04.CrossRefGoogle ScholarPubMed
Kivett, V. R. (1993) Racial comparisons of the grandmother role: Implications for strengthening the family support system of older black women. Family Relations 42:165–72.CrossRefGoogle Scholar
Kohler, H.-P., Billari, F. C. & Ortega, J. A. (2002) The emergence of lowest-low fertility in Europe during the 1990s. Population and Development Review 28:641–80.CrossRefGoogle Scholar
Kohli, M. (1999) Private and public transfers between generations: Linking the family and the state. European Societies 1:81–104.CrossRefGoogle Scholar
Kohli, M. (2004) Intergenerational transfers and inheritance: A comparative view. In: Intergenerational relations across time and place (Annual Review of Gerontology and Geriatrics, vol. 24), ed. Silverstein, M., pp. 266–89. Springer.Google Scholar
Kohli, M. & Künemund, H. (2003) Intergenerational transfers in the family: What motivates giving? In: Global aging and challenges to families, ed. Bengtson, V. L. & Lowenstein, , pp. 123–42. Aldine de Gruyter.Google Scholar
Kohli, M., Künemund, H., Motel, A. & Szydlik, M. (2000) Grunddaten zur Lebenssituation der 40-85 jährigen deutschen Bevölkerung. Ergebnisse des Alters-Survey [Basic data on the living situation of 40- to 85-year-old Germans: Result of the age survey]. Weißensee.Google Scholar
Korkeila, K., Korkeila, J., Vahtera, J., Kivimaki, M., Kivela, S.-L., Sillanmaki, L. & Koskenvuo, M. (2005) Childhood adversities, adult risk factors and depressiveness: A population study. Social Psychiatry and Psychiatric Epidemiology 40:700–06.CrossRefGoogle ScholarPubMed
Kotlikoff, L. J. & Summers, L. H. (1981) The role of intergenerational transfers in aggregate capital accumulation. Journal of Political Economy 89:706–32.CrossRefGoogle Scholar
Kramer, K. L. (2002) Variation in juvenile dependence: Helping behavior among Maya children. Human Nature 13:299–325.CrossRefGoogle ScholarPubMed
Kramer, K. L. (2005a) Children's help and the pace of reproduction: Cooperative breeding in humans. Evolutionary Anthropology 14:224–37.CrossRefGoogle Scholar
Kurland, J. A. (1979) Paternity, mother's brother, and human sociality. In: Evolutionary biology and human social behavior: An anthropological perspective, ed. Chagnon, N. A. & Irons, W. G., pp. 145–80. Duxbury Press.Google Scholar
Laferrère, A. & Wolff, F.-C. (2006) Microeconomic models of family transfers. In: Handbook of the economics of giving, altruism and reciprocity, vol. 2: Applications, ed. Kolm, S. C. & Ythier, J. M., pp. 889–969. Handbooks in Economics 23. North-Holland/Elsevier.Google Scholar
Laham, S. M., Gonsalkorale, K. & von Hippel, W., (2005) Darwinian grandparenting: Preferential investment in more certain kin. Personality and Social Psychology Bulletin 31:63–72.CrossRefGoogle ScholarPubMed
Lahdenperä, M., Lummaa, V., Helle, S., Tremblay, M. & Russell, A. F. (2004) Fitness benefits of prolonged post-reproductive lifespan in women. Nature 428:178–81.CrossRefGoogle ScholarPubMed
Lahdenperä, M., Russell, A. F. & Lummaa, V. (2007) Selection for long lifespan in men: Benefits of grandfathering? Proceedings of the Royal Society of London B: Biological Sciences 274:2437–44.Google ScholarPubMed
Lancaster, J. B., Kaplan, H. S., Hill, K. & Hurtado, A. M. (2000) The evolution of life history, intelligence, and diet among chimpanzees and human foragers. In: Perspectives in ethology: Evolution, culture, and behavior, vol. 13, pp. 47–72. Plenum.CrossRefGoogle Scholar
Lancaster, J. B. & King, B. J. (1985) An evolutionary perspective on menopause. In: In her prime: A new view of middle-aged women, ed. Kerns, V. & Brown, J. K., pp. 13–20. Bergen and Garvey.Google Scholar
Lancaster, J. B. & Lancaster, C. S. (1983) Parental investment: The hominid adaptation. In: How humans adapt: A biocultural odyssey, ed. Ortner, D., pp. 33–66. Proceedings of the Smithsonian's Seventh International Symposium. Smithsonian Institution.Google Scholar
Lavers, C. A. & Sonuga-Barke, E. J. S. (1997) Annotation: On the grandmothers' role in the adjustment and maladjustment of grandchildren. Journal of Child Psychology and Psychiatry 38:747–53.CrossRefGoogle ScholarPubMed
Lawson, D. W. & Mace, R. (2009) Trade-offs in modern parenting: A longitudinal study of sibling competition for parental care. Evolution and Human Behavior 30:170–83.CrossRefGoogle Scholar
Lee, R. D. (1997) Intergenerational relations and the elderly. In: Between Zeus and the salmon: The biodemography of longevity, ed. Wachter, K. W. & Finch, C. E. pp. 212–33. National Academy Press.Google Scholar
Lee, R. D. (2003a) Rethinking the evolutionary theory of aging: Transfers, not births, shape senescence in social species. Proceedings of the National Academy of Sciences of the United States of America 100:9637–42.CrossRefGoogle Scholar
Lee, R. D. (2003b) The demographic transition: Three centuries of fundamental change. Journal of Economic Perspectives 17:167–90.CrossRefGoogle Scholar
Lee, R. D. (2008) Sociality, selection, and survival: Simulated evolution of mortality with intergenerational transfers and food sharing. Proceedings of the National Academy of Sciences USA 105:7124–28.CrossRefGoogle ScholarPubMed
Lee, R. D., Ensminger, M. E. & LaVeist, T. A. (2005) The responsibility continuum: Never primary, coresident and caregiver – Heterogeneity in the African-American grandmother experience. International Journal of Aging and Human Development 60:295–304.CrossRefGoogle ScholarPubMed
Lee, S., Colditz, G., Berkman, L. & Kawachi, I. (2003) Caregiving to children and grandchildren and risk of coronary heart disease in women. American Journal of Public Health 93:1939–44.CrossRefGoogle ScholarPubMed
Leek, M. & Smith, P. K. (1991) Cooperation and conflict in three-generation families. In: The psychology of grandparenthood, ed. Smith, P. K., pp. 177–94. Routledge.Google Scholar
Leonetti, D. L., Nath, D. C. & Hemam, N. S. (2007) In-law conflict. Women's reproductive lives and the roles of their mothers and husbands among the matrilineal Khasi. Current Anthropology 48:861–90.CrossRefGoogle Scholar
Leonetti, D. L., Nath, D. C., Hemam, N. S. & Neill, D. B. (2005) Kinship organization and the impact of grandmothers on reproductive success among the matrilineal Khasi and patrilineal Bengali of northeast India. In: Grandmotherhood: The evolutionary significance of the second half of female life, ed. Voland, E., Chasiotis, A. & Schiefenhövel, W., pp. 194–214. Rutgers University Press.Google Scholar
Levitt, M. J., Weber, R. A. & Clark, M. C. (1986) Social network relationships as sources of maternal support and well-being. Developmental Psychology 22:310–16.CrossRefGoogle Scholar
Lin, C.-H. (2003) Intergenerational parallelism of self-efficacy: Moderating variables, mediating variables, and common antecedents. Doctoral dissertation, Department of Sociology, Texas A&M University, Dissertation Abstracts International, DAI-A 65/07, p. 2783. (AAT 3141190).Google Scholar
Mace, R. (1998) The coevolution of human fertility and wealth inheritance strategies. Philosophical Transactions of the Royal Society B: Biological Sciences 353:389–97.CrossRefGoogle ScholarPubMed
Mace, R. (2000) Evolutionary ecology of human life history. Animal Behaviour 59:1–10.CrossRefGoogle ScholarPubMed
Mace, R. & Sear, R. (2005) Are humans cooperative breeders? In: Grandmotherhood: The evolutionary significance of the second half of female life, ed. Voland, E., Chasiotis, A. & Schiefenhövel, W., pp. 143–59). Rutgers University Press.Google Scholar
Madrigal, L. & Melendez-Obando, M. (2008) Grandmothers' longevity negatively affects daughters' fertility. American Journal of Physical Anthropology 136:223–29.CrossRefGoogle ScholarPubMed
Manton, K. G., Gu, X. & Lowrimore, G. R. (2008) Cohort changes in active life expectancy in the U.S. elderly population: Experience from 1982–2004 national long-term care survey. The Journals of Gerontology. Series B: Psychological Sciences and Social Sciences 63B:S269–81.CrossRefGoogle Scholar
Marks, G. N. (2006) Family size, family type and student achievement: Cross-national differences and the role of socioeconomic and school factors. Journal of Comparative Family Studies 37:1–24.CrossRefGoogle Scholar
Masvie, H. (2006) The role of Tamang mothers-in-law in promoting breast feeding in Makwanpur District, Nepal. Midwifery 22:23–31.CrossRefGoogle ScholarPubMed
Maynard Smith, J. (1964) Group selection and kin selection. Nature 201:1145–47.CrossRefGoogle Scholar
Mayr, E. (1961) Cause and effect in biology. Science 134:1501–506.CrossRefGoogle ScholarPubMed
McClellan, W. M., Stanwyck, D. J. & Anson, C. A. (1993) Social support and subsequent mortality among patients with end-stage renal disease. Journal of the American Society of Nephrology 4:1028–34.CrossRefGoogle ScholarPubMed
McHenry, H. M. (1994) Behavioral ecological implications of early hominid body size. Journal of Human Evolution 27:77–87.CrossRefGoogle Scholar
Medawar, P. B. (1952) An unsolved problem of biology. H. K. Lewis.Google Scholar
Meehan, C. L. (2005) The effects of residential locality on parental and alloparental investment among the Aka foragers of the Central African Republic. Human Nature 16:58–80.CrossRefGoogle ScholarPubMed
Mills, T. L., Wakeman, M. A. & Fea, C. B. (2001) Adult grandchildren's perceptions of emotional closeness and consensus with their maternal and paternal grandparents. Journal of Family Issues 22:427–55.CrossRefGoogle Scholar
Mitchell, W. (2007) Research review: The role of grandparents in intergenerational support for families with disabled children: A review of the literature. Child and Family Social Work 12:94–101.CrossRefGoogle Scholar
Modin, B. & Fritzell, J. (2009) The long arm of the family: Are parental and grandparental earnings related to young men's body mass index and cognitive ability? International Journal of Epidemiology 38:724–32.CrossRefGoogle Scholar
Monserud, M. A. (2008) Intergenerational relationships and affectual solidarity between grandparents and young adults. Journal of Marriage and Family 70:182–95.CrossRefGoogle Scholar
Moore, M. R. & Brooks-Gunn, J. (2002) Adolescent parenthood. In: Handbook of parenting, vol. 3: Being and becoming a parent, 2nd edition, ed. Bornstein, M. H., pp. 173–214. Erlbaum.Google Scholar
Murphy, M. J. & Grundy, E. (2003) Mothers with living children and children with living mothers: The role of fertility and mortality in the period 1911–2050. Population Trends 112:36–44.Google Scholar
Murray, C. J. L. & Lopez, A. D. (1997) Alternative projections of mortality and disability by cause, 1990–2020: Global Burden of Disease Study. The Lancet 349:1498–504.CrossRefGoogle ScholarPubMed
Myrskylä, M., Kohler, H.-P. & Billari, F. C. (2009) Advances in development reverse fertility declines. Nature 460:741–43.CrossRefGoogle ScholarPubMed
Oakley, L., Doyle, P. & Maconochie, N. (2008) Lifetime prevalence of infertility and infertility treatment in the UK: Results from a population-based survey of reproduction. Human Reproduction 23:447–50.CrossRefGoogle ScholarPubMed
Oburu, P. O. (2005) Caregiving stress and adjustment problems of Kenyan orphans raised by grandmothers. Infant and Child Development 14:199–210.CrossRefGoogle Scholar
Oburu, P. O. & Palmerus, K. (2005) Stress related factors among primary and part-time caregiving grandmothers of Kenyan grandchildren. International Journal of Aging and Human Development 60:273–82.CrossRefGoogle ScholarPubMed
O'Hara, M. W. & Swain, A. M. (1996) Rates and risk of postpartum depression: A meta-analysis. International Review of Psychiatry 8:37–54.CrossRefGoogle Scholar
Okabayashi, H., Liang, J., Krause, N., Akiyama, H. & Sugisawa, H. (2004) Mental health among older adults in Japan: Do sources of social support and negative interaction make a difference? Social Science and Medicine 59:2259–70.CrossRefGoogle Scholar
Oyserman, D., Radin, N. & Benn, R. (1993) Dynamics in a three-generational family: Teens, grandparents, and babies. Developmental Psychology 29:564–72.CrossRefGoogle Scholar
Packer, C., Tatar, M. & Collins, A. (1998) Reproductive cessation in female mammals. Nature 392:807–11.CrossRefGoogle ScholarPubMed
Pallock, L. L. & Lamborn, S. D. (2006) Beyond parenting practices: Extended kinship support and the academic adjustment of African-American and European-American teens. Journal of Adolescence 29:813–28.CrossRefGoogle ScholarPubMed
Pashos, A. (2000) Does parental uncertainty explain discriminative grandparental solicitude? A cross-cultural study in Greece and Germany. Evolution and Human Behavior 21:97–109.CrossRefGoogle Scholar
Pashos, A. & McBurney, D. H. (2008) Kin relationships and the caregiving biases of grandparents, aunts and uncles: A two-generational questionnaire study. Human Nature 19:311–30.CrossRefGoogle ScholarPubMed
Patterson, C. J., Hurt, S. & Mason, C. D. (1998) Families of the lesbian baby boom: Children's contact with grandparents and other adults. American Journal of Orthopsychiatry 68:390–99.CrossRefGoogle ScholarPubMed
Paul, A. (2005) Primate predispositions for human grandmaternal behavior. In: Grandmotherhood: The evolutionary significance of the second half of female life, ed. Voland, E., Chasiotis, A. & Schiefenhövel, W., pp. 21–37. Rutgers University Press.Google Scholar
Pavard, S., Koons, D. N. & Heyer, E. (2007) The influence of maternal care in shaping human survival and fertility. Evolution 61:2801–10.CrossRefGoogle ScholarPubMed
Pavelka, M. S. M. & Fedigan, L. M. (1991) Menopause: A comparative life history perspective. Yearbook of Physical Anthropology 34:13–38.CrossRefGoogle Scholar
Peccei, J. S. (1995) The origin and evolution of menopause: The altriciality-lifespan hypothesis. Ethology and Sociobiology 16:425–49.CrossRefGoogle Scholar
Peccei, J. S. (2001a) A critique of the grandmother hypotheses: Old and new. American Journal of Human Biology 13:434–52.CrossRefGoogle ScholarPubMed
Peccei, J. S. (2001b) Menopause: Adaptation or epiphenomenon? Evolutionary Anthropology 10:43–57.CrossRefGoogle Scholar
Penn, D. J. & Smith, K. R. (2007) Differential fitness costs of reproduction between the sexes. Proceedings of the National Academy of Sciences USA 104:553–58.CrossRefGoogle ScholarPubMed
Poehlmann, J. (2005) Children's family environments and intellectual outcomes during maternal incarceration. Journal of Marriage and Family 67:1275–85.CrossRefGoogle Scholar
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 41:355–79.CrossRefGoogle ScholarPubMed
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 4:203–13.CrossRefGoogle Scholar
Pope, S. K., Whiteside, I., Brooks-Gunn, J., Kelleher, K. J., Rickert, V. I., Bradley, R. H. & Casey, P. H. (1993) Low-birth-weight infants born to adolescent mothers. Effects of coresidency with grandmother on child-development. Journal of the American Medical Association 269:1396–400.CrossRefGoogle ScholarPubMed
Post, S. G. (2005) Altruism, happiness, and health: It's good to be good. International Journal of Behavioral Medicine 12:66–77.CrossRefGoogle Scholar
Presser, H. B. (1989) Some economic complexities of child care provided by grandmothers. Journal of Marriage and Family 51:581–91.CrossRefGoogle Scholar
Preston, S. O. & de Waal, F. B. M. (2002) Empathy: Its ultimate and proximate bases. Behavioral and Brain Sciences 25:1–72.CrossRefGoogle ScholarPubMed
Reitzes, D. C. & Mutran, E. J. (2004) Grandparenthood: Factors influencing frequency of grandparent–grandchildren contact and grandparent role satisfaction. The Journals of Gerontology. Series B: Psychological Sciences and Social Sciences 59B:S9–S16.CrossRefGoogle Scholar
Robbins, M. S., Briones, E., Schwartz, S. J., Dillon, F. R. & Mitrani, V. B. (2006) Differences in family functioning in grandparent and parent-headed households in a clinical sample of drug-using African American adolescents. Cultural Diversity and Ethnic Minority Psychology 12:84–100.CrossRefGoogle Scholar
Rogers, A. R. (1993) Why menopause? Evolutionary Ecology 7:406–20.CrossRefGoogle Scholar
Rose, H. & Rose, S. (2001) Alas poor Darwin: Arguments against evolutionary psychology. Vintage.Google Scholar
Ross, M. E. T. & Aday, L. A. (2006) Stress and coping in African American grandparents who are raising their grandchildren. Journal of Family Issues 27:912–32.CrossRefGoogle Scholar
Rossi, A. S. & Rossi, P. H. (1990) Of human bonding: Parent–child relations across the life course. Aldine de Gruyter.Google Scholar
Runyan, D. K., Hunter, W. M., Socolar, R. R., Amaya-Jackson, L., English, D., Landsverk, J., Dubowitz, H., Browne, D. H., Bangdiwala, S. I. & Mathew, R. M. (1998) Children who prosper in unfavorable environments: The relationship to social capital. Pediatrics 101:12–18.CrossRefGoogle ScholarPubMed
Salmon, C. A. & Daly, M. (1998) Birth order and familial sentiment: Middleborns are different. Evolution and Human Behavior 19:299–312.CrossRefGoogle Scholar
Sanfey, A. G., Rilling, J. K., Aronson, J. A., Nystrom, L. E. & Cohen, J. D. (2003) The neural basis of economic decision-making in the ultimatum game. Science 300:1755–1758.CrossRefGoogle ScholarPubMed
Scholl Perry, K. (1996) Relationships among adolescents' ego development, their academic achievement, and the amount of their contact with and social distance from grandparents. Doctoral dissertation, Department of Psychology, Pace University, New York. Dissertation Abstracts International, DAI-B 57/08, p. 5391. (AAT 9701161)Google Scholar
Schölmerich, A., Leyendecker, B., Citlak, B., Miller, A. & Harwood, R. (2005) Variability of grandmother's roles. In: Grandmotherhood: The evolutionary significance of the second half of female life, ed. Voland, E., Chasiotis, A. & Schiefenhövel, W., pp. 277–92. Rutgers University Press.Google Scholar
Schröder-Butterfill, E. (2004) Inter-generational family support provided by older people in Indonesia. Ageing and Society 24:497–530.CrossRefGoogle ScholarPubMed
Schultz, N. W. (1980) A cognitive-developmental study of the grandchild–grandparent bond. Child Study Journal 10:7–26.Google Scholar
Schwartz, J. & Waldrop, J. (1992) The growing importance of grandparents if you're marketing products and services for children and young adults. American Demographics 14:10–11.Google Scholar
Sear, R. (2008) Kin and child survival in rural Malawi: Are matrilineal kin always beneficial in a matrilineal society? Human Nature 19:277–93.CrossRefGoogle Scholar
Sear, R. & Mace, R. (2008) Who keeps children alive? A review of the effects of kin on child survival. Evolution and Human Behavior 29:1–18.CrossRefGoogle Scholar
Sear, R., Mace, R. & McGregor, I. A. (2000) Maternal grandmothers improve nutritional status and survival of children in rural Gambia. Proceedings of the Royal Society B: Biological Sciences 267:1641–47.CrossRefGoogle ScholarPubMed
Shanley, D. P. & Kirkwood, T. B. L. (2001) Evolution of the human menopause. BioEssays 23:282–87.3.0.CO;2-9>CrossRefGoogle ScholarPubMed
Shanley, D. P., Sear, R., Mace, R. & Kirkwood, T. B. L. (2007) Testing evolutionary theories of menopause. Proceedings of the Royal Society of London B: Biological Sciences 274:2943–49.Google ScholarPubMed
Shanok, A. F. & Miller, L. (2007) Stepping up to motherhood among inner-city teens. Psychology of Women Quarterly 31:252–61.CrossRefGoogle Scholar
Sherman, P. W. (1998) The evolution of menopause. Nature 392:759–60.CrossRefGoogle ScholarPubMed
Silk, J. B., Brosnan, S. F., Vonk, J., Henrich, J., Povinelli, D. J., Richardson, A. S., Lambeth, S. P., Mascaro, J. & Schapiro, S. J. (2005) Chimpanzees are indifferent to the welfare of unrelated group members. Nature 437:1357–59.CrossRefGoogle Scholar
Silverstein, M. & Ruiz, S. (2006) Breaking the chain: How grandparents moderate the transmission of maternal depression to their grandchildren. Family Relations 55:601–12.CrossRefGoogle Scholar
Skaznik-Wikiel, M., Tilly, J. C., Lee, H.-J., Niikura, Y., Kaneko-Tarui, T., Johnson, J. & Tilly, J. L. (2007) Serious doubts over “eggs forever?”. Differentiation 75:93–99.CrossRefGoogle Scholar
Smith, M. S. (1987) Evolution and developmental psychology: Toward a sociobiology of human development. In: Sociobiology and psychology: Ideas, issues, and applications, ed. Crawford, C., Smith, M. & Krebs, D. pp. 225–52. Erlbaum.Google Scholar
Smith, M. S. (1988) Research in developmental sociobiology: Parenting and family behavior. In: Sociobiological perspectives on human development, ed. MacDonald, K. B., pp. 271–92. Springer.CrossRefGoogle Scholar
Smith, M. S. (1991) An evolutionary perspective on grandparent–grandchild relationships. In: The psychology of grandparenthood, ed. Smith, P. K., pp. 155–75. Routledge.Google Scholar
Smith, M. S., Kish, B. J. & Crawford, C. B. (1987) Inheritance of wealth as human kin investment. Ethology and Sociobiology 8:171–82.CrossRefGoogle Scholar
Smith, P. K. & Drew, L. (2002) Grandparenthood. In: Handbook of parenting: Vol. 3. Being and becoming a parent, 2nd edition, ed. Bornstein, M. H., pp. 141–72. Erlbaum.Google Scholar
Smith, P. K. & Drew, L. (2004) Grandparenting and extended support networks. In: Sage handbook of parenting, ed. Hohhughi, M. & Long, N., pp. 146–59. Sage.Google Scholar
Spieker, S. J. & Bensley, L. (1994) Roles of living arrangements and grandmother social support in adolescent mothering and infant attachment. Developmental Psychology 30:102–11.CrossRefGoogle Scholar
Stack, C. B. (1975) All our kin: Strategies for survival in a Black community. Harper & Row.Google Scholar
Steinbach, I. & Henke, W. (1998) Grosselterninvestment – eine empirische interkulturelle Vergleichsstudie [Grandparental investment – An empirical cross-cultural comparative study]. Anthropologie 36:293–301.Google Scholar
Stevens, J. H. (1988) Social support, locus of control, and parenting in three low-income groups of mothers: Black teenagers, black adults, and white adults. Child Development 59:635–42.CrossRefGoogle ScholarPubMed
Strassman, B. I. & Dunbar, R. I. (1999) Human evolution and disease: Putting the Stone Age in perspective. In: Evolution in health and disease, ed. Stearns, S. C., pp. 91–101). Oxford University Press.Google Scholar
Streib, G. F. (1958) Family patterns in retirement. Journal of Social Issues 14:46–60.CrossRefGoogle Scholar
Sugiyama, L. S. (2004) Illness, injury, and disability among Shiwiar forager-horticulturalists: Implications of health-risk buffering for the evolution of human life history. American Journal of Physical Anthropology 123:371–89.CrossRefGoogle ScholarPubMed
Surkan, P. J., Ryan, L. M., Carvalho Vieira, L. M., Berkman, L. F. & Peterson, K. E. (2007) Maternal social and psychological conditions and physical growth in low-income children in Piauí, Northeast Brazil. Social Science and Medicine 64:375–88.CrossRefGoogle Scholar
Szinovacz, M. E. (1998a) Grandparents today: A demographic profile. The Gerontologist 38:37–52.CrossRefGoogle ScholarPubMed
Szinovacz, M. E. (1998b) Research on grandparenting: Needed refinements in concepts, theories, and methods. In: Handbook on grandparenthood, ed. Szinovacz, M. E., pp. 257–88. Greenwood Press.Google Scholar
Thomas, M. & Avery, V. (1997) Infant feeding in Asian families: Early feeding practices and growth. The Stationery Office, London.Google Scholar
Thompson, R. A., Tinsley, B. R., Scalora, M. J. & Parke, R. D. (1989) Grandparents' visitation rights: Legalizing the ties that bind. American Psychologist 44:1217–22.CrossRefGoogle Scholar
Tinsley, B. R. & Parke, R. D. (1984) Grandparents as support and socialization agents. In: Beyond the dyad, ed. Lewis, M., pp. 161–94. Plenum.CrossRefGoogle Scholar
Tinsley, B. J. & Parke, R. D. (1987) Grandparents as interactive and social support agents for families with young infants. International Journal of Aging and Human Development 25:259–77.CrossRefGoogle ScholarPubMed
Tolson, T. F. J. & Wilson, M. N. (1990) The impact of two- and three-generational black family structure on perceived family climate. Child Development 61:416–28.CrossRefGoogle Scholar
Tomlin, A. M. (1998) Grandparents' influences on grandchildren. In: Handbook on grandparenthood, ed. Szinovacz, M. E., pp. 159–70. Greenwood Press.Google Scholar
Trivers, R. L. (1972) Parental investment and sexual selection. In: Sexual selection and the descent of man 1871–1971, ed. Campbell, B. G., pp. 136–79. Aldine.Google Scholar
Trivers, R. L. & Willard, D. E. (1973) Natural selection of parental ability to vary the sex ratio of offspring. Science 179:90–92.CrossRefGoogle ScholarPubMed
Turke, P. W. (1988) Helpers at the nest: Childcare networks on Ifaluk. In: Human reproductive behaviour: A Darwinian perspective, ed. Betzig, L., Borgerhoff Mulder, M. & Turke, P., pp. 173–88. Cambridge University Press.Google Scholar
Turke, P. W. (1997) Hypothesis: Menopause discourages infanticide and encourages continued investment by Agnates. Evolution and Human Behavior 18:3–13.CrossRefGoogle Scholar
Uhlenberg, P. (1996) Mortality decline in the twentieth century and supply of kin over the life course. The Gerontologist 36:681–85.CrossRefGoogle ScholarPubMed
Uhlenberg, P. (2009) Children in an aging society. The Journals of Gerontology. Series B: Psychological Sciences and Social Sciences 64B:489–96.CrossRefGoogle Scholar
Uhlenberg, P. & Hammill, B. G. (1998) Frequency of grandparental contact with grandchild sets: Six factors that make a difference. The Gerontologist 38:276–85.CrossRefGoogle Scholar
Van Bavel, J. (2006) The effect of fertility limitation on intergenerational social mobility: The quality-quantity trade-off during the demographic transition. Journal of Biosocial Science 38:553–69.CrossRefGoogle ScholarPubMed
Victora, C. G. & WHO Collaborative Study Team (2000) Effect of breastfeeding on infant and child mortality due to infectious diseases in less developed countries. A pooled analysis. WHO Collaborative Study Team on the Role of Breastfeeding on the Prevention of Infant Mortality. The Lancet 355:451–55.Google Scholar
Voland, E. & Beise, J. (2002) Opposite effects of maternal and paternal grandmothers on infant survival in historical Krummhörn. Behavioral Ecology and Sociobiology 52:435–43.CrossRefGoogle Scholar
Voland, E. & Beise, J. (2005) “The husband's mother is the devil in house”: Data on the impact of the mother-in-law on stillbirth mortality in historical Krummhörn (1750–1874) and some thoughts on the evolution of postgenerative female life. In: Grandmotherhood: The evolutionary significance of the second half of female life, ed. Voland, E., Chasiotis, A. & Schiefenhövel, W., pp. 239–55. Rutgers University Press.Google Scholar
Voland, E., Chasiotis, A. & Schiefenhövel, W. (2005) Grandmotherhood: A short overview of three fields of research on the evolutionary significance of postgenerative female life. In: Grandmotherhood: The evolutionary significance of the second half of female life, ed. Voland, E., Chasiotis, A. & Schiefenhövel, W., pp. 1–17. Rutgers University Press.Google Scholar
Vonk, J., Brosnan, S. F., Silk, J. B., Henrich, J., Richardson, A. S., Lambeth, S. P., Schapiro, S. J. & Povinelli, D. J. (2007) Chimpanzees do not take advantage of very low cost opportunities to deliver food to unrelated group members. Animal Behaviour 75:1757–70.CrossRefGoogle Scholar
Walker, R. S, Gurven, M., Burger, O. & Hamilton, M. J. (2008) The trade-off between number and size of offspring in humans and other primates. Proceedings of the Royal Society of London B: Biological Sciences 275:827–34.Google ScholarPubMed
Warneken, F., Hare, B., Melis, A. P., Hanus, D. & Tomasello, M. (2007) Spontaneous altruism by chimpanzees and young children. PLoS Biology 5:e184.CrossRefGoogle ScholarPubMed
Watson, J. A., Rudolph, S. M. & Lyons, J. L. (2005) African-American grandmothers as health educators in the family. International Journal of Aging and Human Development 60:343–56.CrossRefGoogle ScholarPubMed
Weiss, K. M. (1981) Evolutionary perspectives on human aging. In: Other ways of growing old: Anthropological perspectives, ed. Amoss, P. T. & Harrell, S., pp. 25–58. Stanford University Press.CrossRefGoogle Scholar
Weissman, M. M., Wickramaratne, P., Nomura, Y., Warner, V., Pilowsky, D. & Verdeli, H. (2006) Offspring of depressed parents: 20 years later. American Journal of Psychiatry 163:1001–1008.CrossRefGoogle ScholarPubMed
Werner, P., Lowenstein, A. & Katz, R. (1998) The meaning of grandparenthood: A critical review and research agenda. Aging Clinical and Experimental Research 10:431–39.CrossRefGoogle ScholarPubMed
WHO/UNICEF (1990) The Innocenti declaration on the protection, promotion and support of breastfeeding. Florence, Italy, August 1, 1990. Retrieved December 17, 2007 from: http://www.unicef.org/nutrition/index_24807.html Google Scholar
Williams, G. C. (1957) Pleiotropy, natural selection, and the evolution of senescence. Evolution 11:398–411.CrossRefGoogle Scholar
Wilson, D. S. & Wilson, E. O. (2007) Rethinking the theoretical foundation of sociobiology. Quarterly Review of Biology 82:327–48.CrossRefGoogle ScholarPubMed
Wolff, F. C. (2000) Transferts et redistribution familiale collective. Revue Économique 51:143–62.Google Scholar
Wood, S. & Liossis, P. (2007) Potentially stressful life events and emotional closeness between grandparents and adult grandchildren. Journal of Family Issues 28:380–98.CrossRefGoogle Scholar
Yong, F. (2006) Structural factors, types of grandparenting, and grandparents' well-being: Building causal mechanisms of grandparenting in an aging society. Doctoral dissertation, School of Social Welfare, State University of New York at Albany. Dissertation Abstracts International, DAI-A 67/10, p. 3935. (AAT 3239165).Google Scholar
Zervas, L. J. & Sherman, M. F. (1994) The relationship between perceived parental favoritism and self-esteem. Journal of Genetic Psychology 169:281–88.Google Scholar