Raising a child doesn't take a village, research shows

Sep 09, 2011 By Diane Swanbrow

It doesn't take a village to raise a child after all, according to University of Michigan research.

"In the African villages that I study in Mali, children fare as well in nuclear families as they do in ," said U-M researcher Beverly Strassmann, professor of and faculty associate at the U-M Institute for Social Research (ISR). "There's a naïve belief that villages raise children communally, when in reality children are raised by their own families and their survival depends critically on the survival of their mothers."

Strassmann's recently published studies provide the first empirical data on two theoretical pillars of the belief that it takes a village to raise a child. One of these is the grandmother hypothesis—the idea that a child is more likely to survive if a grandmother is nearby.

This video is not supported by your browser at this time.

The other is cooperative breeding theory, based on animal behavior studies that have shown that in a wide variety of birds, including scrub jays, and many mammals, such as the mongoose, adults may delay their own reproduction to help raise the offspring of others.

"Some researchers have suggested that humans may also be a cooperatively breeding species," said Strassmann, who views human behavior from the perspective of evolutionary biology. "But the evidence I found shows that this is not always the case and there can be quite a lot of competition and coercion within families."

In a study published this summer in the Proceedings of the National Academy of Sciences, Strassmann analyzed data on child survival in various family structures from her ongoing, 25-year study of the Dogon people of Mali, West Africa, a traditional, agricultural society in which resources are scarce and mortality is high. Like many human groups in the past, Dogon society is patrilineal, with a tight-knit web of kinship established through fathers. The Dogon practice polygyny and do not use contraception; Dogon women give birth to 9 children, on average, over their lifetimes.

Strassmann's study is the only research on the subject to date that is both prospective in nature and that controls for confounding variables, such as family wealth and family structure, that could affect child survival.

In the 1,700 Dogon children she followed, Strassmann found that children were over four times more likely to die by age 5 if their mothers were dead.

"In the Dogon, it is mothers alone who are critical for getting children past the early-life bottleneck in survival," Strassmann said. "Adding an extra adult to the family did not improve a child's survival. Although it's important to note that these findings are about child survival up to age 5, they don't speak to the value of having grandparents later on.

"Children were 52 percent less likely to die if their paternal grandparents were dead. Why? Because in a patrilineal society, the paternal grandparents are likely to live with the child, competing for scarce resources."

In another study, published this summer in Human Nature, Strassmann and ISR researcher Wendy Garrard further investigated the validity of the grandmother hypothesis. This study involved a meta-analysis of published studies done over several centuries in 17 patrilineal societies in Africa, Asia, Europe and North America.

"Our analysis showed that the grandparents who actually lived with their grandchildren did not have a beneficial effect on the grandchildren's survival," Strassmann said. "Grandparents who did not live with the grandchildren sometimes did have a positive effect because they were not competing for scarce resources.

"Cooperative breeding is not the universal, evolved pattern. Instead there is huge diversity in the array of successful family systems in humans. For example, in the U.S., there are a huge proportion of nuclear families and single moms. Certainly many children of single mothers not only survive but thrive. Look at Bill Clinton and Barack Obama.

"Cooperative breeding does help to understand 19th century European societies, for example, in Ireland, where marriage was postponed to the late 20s or even 30s due to the scarcity of farms to inherit. In these societies, celibate individuals often worked on the farms of siblings as helpers and can be compared to cooperatively breeding birds that delay reproduction and act as helpers at their parents' nest when the habitat is saturated and all nest sites are taken. However, cooperative breeding does not fit many other societies, such as the one I study in Africa."

In her study of the Dogon, Strassmann found that children's risk of death is higher in polygynous than in monogamous families. This reflects the hazard of living with unrelated females whose own children are competing with the children of co-wives for limited resources.

Supporting this finding, Strassmann cites "Hamilton's Rule," established by British evolutionary biologist W.D. Hamilton in the 1960s. It is the first formal, mathematical description of kin selection theory, the idea that the degree to which we are willing to invest our resources in another person depends, in part, on the degree of genetic kinship we share with them.

But kinship cuts both ways, according to Strassmann.

"Our results also suggest that kin competition is an important aspect of human family systems," she said. "Genetic conflicts of interest occur even within the family. This competition starts before birth, with maternal genes allocating resources strategically between present and future offspring. The competition extends throughout childhood with sibling rivalry.

"At reproductive maturity, kin compete for the resources needed for mating and parental effort. And finally, in old age, net producers eventually become net consumers who compete with other family members for food and shelter.

"The grandmother hypothesis does not take into account that grandmothers may need help themselves, not just among the groups like the Dogon but in societies like our own."

Explore further: Researchers find a way of avoiding overhead aversion in charity donations

add to favorites email to friend print save as pdf

Related Stories

New research provides insight into menopause

Mar 31, 2008

Insight into why females of some species undergo menopause while others do not has proven elusive despite an understanding of the biological mechanisms behind the change.

Mothers trade child quantity for quality

Jan 23, 2008

Researchers at the University of Sheffield have shown that mothers are choosing to have fewer children in order to give their children the best start in life, but by doing so are going against millenia of human evolution. ...

Empty nest syndrome may not be bad after all, study finds

Feb 21, 2008

One day they are crawling, the next day they are driving and then suddenly they aren’t kids anymore. As children reach adulthood, the parent-child relationship changes as parents learn to adapt to newly independent children. ...

Grandparents favor genetically close grandchildren

Apr 29, 2010

(PhysOrg.com) -- New research suggests that grandparents naturally and subconsciously favor the grandchildren who are most closely related to them genetically. The phenomenon is called "sexually antagonistic ...

Recommended for you

How people respond to a catastrophe on social media

22 hours ago

When an earthquake hits, it makes more than just seismic waves. Extreme events such as earthquakes, tsunamis, and terrorist attacks also produce waves of immediate online social interactions, in the form ...

Making cities more accessible for everyone

22 hours ago

Ron Buliung's interest in urban design initially started with his travels to Europe and India where he saw how different cities dealt with issues such as space, wealth, poverty, street life, congestion and ...

Scientists show IQs on the rise

23 hours ago

(Phys.org) —Human intelligence is thought to improve with each generation and a unique study of people born and raised in Aberdeen has proved that those in north-east Scotland are getting smarter.

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

Helga
not rated yet Sep 13, 2011
This finding is interesting and logical in some ways in post-neolithic lineage-based societies under conditions of rising population or declining resources. It is not however likely to be true in mobile foragers, as there, the children tend to need grandparents who watch over them while the parents are foraging and/or to spell of the mother while she is in the early post-patrum period. Grandmothers contributed significantly to the caloric level/capita available to the families of their children and grandchildren, by being active forages and child-care attendants - something that was critical in remote camps in a landscape full of large predators.
aj_mayorga
not rated yet Sep 14, 2011
The researchers seem to miss the forest for the trees as they only refer to raising a child as ensuring survival. The proverb's wisdom still holds and is obvious when you consider a community minded group lends to a child extra assurance against physical harm, starvation, fostering in case of parental death, development of social/sexual identity,roles, norms and civic mindedness. In other words it is a proverb that explains to "raise" a child is a multifaceted complex dynamic that is made much easier for parents and to the benefit of the community and child as a group venture. This fact is nothing new and is the reason parents involve their children in Boy/Girl Scouts, 4-H, Little League, Volunteer fund-raisers, etc. These widen the range of our children's experiences and help them to become contributing members of society. In summary the study trivializes the aspects of raising of children and is hardly worthy of being lauded.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.