Encyclopedia of Evolutionary Psychological Science

Living Edition
| Editors: Todd K. Shackelford, Viviana A. Weekes-Shackelford

Alloparenting and Grandparenting

  • Katrina LippoltEmail author
  • Vania Rolon
Living reference work entry
DOI: https://doi.org/10.1007/978-3-319-16999-6_327-1


A system of parenting where people other than the parents act in a parental role and help raise children that are not necessarily their own.


As the social animals we are, we have evolved in ways that promote cooperation because individuals who help each other are more likely to survive in threatening environments than those who do not cooperate. Additionally, because the end goal of evolution is not necessarily to survive but to reproduce and pass one’s genes on to future generations, we have evolved mechanisms that will increase the chances of survival of our offspring. One such mechanism involves having other members of the group aid in the rearing of a child, a term that is known as alloparenting. The following section describes how alloparenting works, and why people may willingly help raise a child that is not theirs.


According to Bentley and Mace (2009), alloparenting is when children are cared after by individuals who are not their biological parents. This includes uncles, aunts, grandparents, siblings, or even other members of the community that are not necessarily immediately genetically related to the children. Because females in general tend to have higher parental investment, it should not come off as a surprise that other females of the group are more likely to help a mother with her child than are men. Additionally, because offspring are the future of one’s genes, an individual female engaging in alloparenting would have to make sure her child will not incur any harm while in the care of other members. As a result, individuals whom the mothers believe will give the child back without injury are more likely to be trusted by the mother (Hrdy 2009). Non kin members may engage in alloparenting behaviors, but it is typically individuals who are blood-related to the child who are more likely to do so, which supports kin selection theory. An aunt helping raise her nieces and nephews shares more genetic makeup with them than a random member of the community, and thus getting them into the future allows some of her genes to survive as well. Meanwhile, non kin members may also provide help, but the reasons and mechanisms for it may differ from those of family members. While kin selection theory explains why uncles, sibling, and grandparents engage in alloparenting, reciprocal altruism theory may shed light on why non kin will also help rear a child. A female may agree to care after a child that is not hers because she knows that the child’s mother may be more likely to return the favor and care after her own offspring if the need ever arises.


A very common form of alloparenting is grandparenting. Grandparents have an influence over the development of their grandchildren (Szinovácz 1998) and can affect a grandchild’s behavior in both direct and indirect ways, such as directly interacting with them and offering advice. It is not uncommon for the older members of a society to help care after the young. Additionally, when it comes to grandparents, it is the mother’s parents who typically invest more in grandchildren than the father’s parents. This may be due to differences in paternal certainty; the mother’s mother can be absolutely sure that her grandchildren are hers, and although the mother’s father has a chance that his daughter is not his, which would mean the grandchildren share no genetic makeup with him, he can at least know the children are the mother’s. Grandparents from the father’s side, however, have no way of knowing if his son has been cuckolded and if any grandchildren are theirs. As a result, the maternal grandmother tends to invest more than the paternal grandmother, and the same goes for the grandfathers.

A prevailing question in evolutionary psychology is why women stop being fertile at a given age. After all, if the end goal is the further reproduction of one’s gene, shouldn’t natural selection favor longer reproductive periods? Hrdy’s (2009) grandmother hypothesis offers a possible explanation of why women experience menopause. This hypothesis suggests that women become infertile at a certain point in their life to stop focusing on having children and to start focusing on taking care of the children and grandchildren they already have. Infertile women in hunter-gatherer societies still collect as much food and work as much as they did during their reproductive years. This means they can provide for any kin they may have, and because grandchildren share a portion of their genes with their grandmothers, investing in the survival of the young would have benefits for the grandmothers’ genes. By staying active in caring for her children and grandchildren, an elderly female can help her daughter eat and stay healthy so that the daughter can focus on bearing more children and provide extra resources to ensure the children’s survival. To support this idea, women with a strong relationship with their mothers are more likely to have more children themselves and to start having them at a younger age than women who do not have close relationships with their mothers. Additionally, grandchildren of grandmothers who did not live long enough to help their daughter reproduce are less likely to survive past infancy.


Alloparenting is an effective strategy to increase the likelihood that one’s offspring survive. Members who are not genetically related to a child may still help raise him or her, but perhaps because of an unspoken expectation that the favor be returned (reciprocal altruism), whereas other kin members such as uncles, aunts, siblings, and grandparents may aid in the rearing of a child because the child is still a vehicle of some of the kin member’s genes. Additionally, grandparents, particularly grandmothers, seem particularly prone to invest time in their grandchildren.



  1. Bentley, G. R., & Mace, R. (2009). Substitute parents: Biological and social perspective on alloparenting across human societies. New York: Berghahn Books.Google Scholar
  2. Hrdy, S. B. (2009). Mothers and others: The evolutionary origins of mutual understanding. Cambridge, MA: Belknap Press of Harvard University Press.Google Scholar
  3. Szinovácz, M. (1998). Handbook on grandparenthood. Westport: Greenwood Press.Google Scholar

Copyright information

© Springer International Publishing AG, part of Springer Nature 2018

Authors and Affiliations

  1. 1.State University of New York at New PaltzNew PaltzUSA

Section editors and affiliations

  • Haley Dillon
    • 1
  1. 1.Dominican CollegeOrangeburgUSA