your big sister may help buffer the effects of stress

a new study found that having older brothers or sisters may protect children against the effects of high stress levels in their mothers.

by maija kappler

published jun 02, 2022

3 minute read

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3 minute read

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there are health benefits to having older siblings

solid relationships with older siblings has a "protective" effect against some of the damage caused by parental stress. getty

maternal stress has a significant impact on childhood development, according to a new study — but older siblings can have such a positive impact that they offset some of that damage. the study, from scientists from several universities and research institutions based in leipzig, germany, tested 373 pairs of mothers and their children, from pregnancy until the child turned 10. the mothers were asked to rate both their stress levels and their child’s behaviour, which researchers then examined to determine patterns.

socio-environmental conditions play a role in stress

they found that socio-environmental conditions, such as a lack of facilities like playgrounds or places where children could play or socialize, had a big part in the stress experienced by pregnant women. people worried about their income or ability to provide for their family were more likely than people who felt secure in their financial future to feel anxious — and that anxiety during pregnancy had tangible effects on their child’s development, even if those results don’t show up for several years. in fact, a 2019 study found that that a mother’s stress level can negatively impact a child in utero even before that child is conceived, via stress hormones and inflammation of the placenta, among other physical impacts.

researchers found that mothers whose stress levels were high while pregnant, and who experienced frequent worry, tension and loss of joy, were more likely to report behavioural problems when their children were seven, eight or 10. surprisingly, bad relationships with neighbours wasn’t a particularly harmful stressor, and neither was having many children. the link between a parent’s stress and their child’s behaviour is “complex,” the study says, and can become a negative cycle, where a child’s social or behavioural problems can exacerbate their parents’ stress level, which may in turn worsen the child’s problems.

“these results confirm previous findings about the negative impact that even mild forms of prenatal stress might have on child behaviour, even after several years,” said federica amici from leipzig university and the max planck institute for evolutionary anthropology, one of the study’s co-authors. the research, she said, also “highlights the importance of early intervention policies that increase maternal wellbeing and reduce the risks of maternal stress already during pregnancy,”

the ‘buffering’ function of older siblings

the good news, though, is that solid relationships with older siblings has a “protective” effect against some of the damage caused by parental stress. “the presence of older siblings overall reduced the likelihood that younger siblings developed behaviour problems during childhood,” the researchers found.

having a positive relationship with older siblings appears to decrease the risk of children “internalizing problems after experiencing stressful events.” this is especially true for children growing up in adverse conditions. researchers still aren’t sure exactly why this is — it may be that older siblings provide a distraction from external stress, or that those positive relationships simply provide comfort and support.

“siblings may learn to understand each other’s thoughts, emotions and intentions from early on, facilitating the development of social, emotional and cognitive skills,” the study found. “moreover, siblings may serve an important promotive or protective function during child development, reducing the occurrence of child behaviour problems and/or mitigating the negative consequences of stressful events.”

older sisters seem to provide the most “protective” function against the impacts of stress, researchers suggest, as previous studies have found that they’re more likely to engage in caretaking behaviour towards their younger siblings than older brothers. boys, too, were more likely to have behavioural problems than girls.

the study authors suggested that future studies should look at cultural differences to see if children from cultures where siblings spend more time together experience even more positive impacts, perhaps looking specifically at families with an increased stress risk, like those with lower income and education levels.