Many studies of household instability focus on how parental divorce or a mother’s romantic relationships influence how often a family relocates and who moves in or out of the home.

But new research in the journal Demography suggests parents themselves account for a relatively small proportion of the household disruptions children in the United States face. In fact, it finds that siblings and other relatives contribute more to household instability than parents do.

This new paper quantifies the amount of instability U.S. children experience over the course of their childhoods. It finds that before their 18th birthday, kids see their household composition — the people they live with — change an average of 4.8 times. They move to a new address an average of 3.4 times.

The average child experiences 1.2 parental changes such as a parent moving out or a stepparent moving in. Meanwhile, children see 1.7 changes involving siblings — for example, the birth of a younger sibling, the arrival of stepsiblings or the departure of siblings and stepsiblings, some of whom move in with other family members or leave for college.

Children, on average, will experience approximately one change related to a grandparent moving in or out of their homes and 1.3 changes involving other family members, according to the analysis, conducted by four scholars from the Population Research Center at the University of Texas at Austin. Approximately one person who isn’t a relative will join or leave the household, on average.

Another key takeaway: 19.8% of all children reside with at least one person who isn’t a relative or with at least one family member who isn’t a parent, stepparent, sibling or stepsibling.

Scholars have established that household instability can have a range of consequences for kids. Changes in family structure are widely viewed as a threat to children’s well-being and are associated with increased behavioral problems and poorer health. When students move from place to place and switch schools frequently, they can fall behind in their studies and have trouble building new relationships with peers and teachers.

While these researchers quantified the household changes children experience, it’s not yet known whether all forms of household instability are harmful to children, the lead author of the paper, R. Kelly Raley, explained. She said more research is needed to investigate whether and how various forms of household instability influence children’s development and well-being.

“A few studies by other scholars provide evidence that divorce isn’t the only form of household instability that matters for child development,” Raley told Journalist’s Resource by email. “We’ve had suggestive evidence that maternal transitions into and out of cohabiting relationships may matter as much as divorce and remarriage for some child developmental outcomes. A small number of studies have examined transition of extended kin and also find that these are associated with poorer child outcomes.”

Raley pointed out that this new study demonstrates that American youth experience significantly more household instability than previously thought — because researchers, in the past, have typically focused narrowly on the mother’s romantic relationship history.

“These findings encourage us to broaden our view of children’s family lives to incorporate a larger variety of kin,” Raley said. “The reality is that many children live with a broad array of kin (and non-kin), albeit often briefly. Even though these experiences are common, we know little about how they contribute to child development.”

Household instability by race, education level

For this study, researchers examined data collected from a nationally representative sample of households that were interviewed every four months over five years as part of the U.S. Census Bureau’s Survey of Income and Program Participation. The SIPP provides a range of data on topics such as family dynamics, education, assets and childcare. This study focuses on 15 waves of data gathered from more than 130,000 people from September 2008 to August 2013.

Raley and her colleagues also learned that household instability tends to vary according to a family’s race and ethnicity and the mother’s education level. Kids whose mothers graduated college move an average of 1.9 times during the course of their childhoods. Their household composition changes an average of 2.7 times. But children with less educated mothers move much more often and have people moving into and out of their homes more often.

Kids whose mothers went to college but did not complete a degree move twice as often as kids with moms who finished college. On average, their household composition changes 4.8 times. Children whose mothers did not get through high school encounter the most disruption, changing addresses an average of 4.3 times and experiencing an average 6.6 shifts in household composition.

Household instability also is higher for black and Hispanic children than for white, non-Hispanic children and Asian children. Black and Hispanic children are most likely to live with “nonnuclear household members.” These household members are not parents or siblings and often don’t stay long, but they likely provide emotional support and other help during times of change, according to the paper, “Estimating Children’s Household Instability Between Birth and Age 18 Using Longitudinal Household Roster Data.”

With additional study, researchers can gauge how the presence of these individuals impact the youngest members of the household.

“Living with nonnuclear kin is common, but we know relatively little about the consequences of this experience for child development,” the authors write in the paper. “Importantly, new dimensions of household instability have the potential to provide researchers with more tools to identify why household instability contributes to child development.”

Want more research on U.S. households. Check out our write-ups on working mothers, housing eviction and the effects of family separation.

This image was obtained from the Flickr account of Wesley Fryer and is being used under a Creative Commons license. No changes were made.

This article first appeared on Journalist’s Resource and is republished here under a Creative Commons license.