Babies may get a bad rap for keeping their parents up all night, but a new study suggests that parental behavior might wreak havoc on their kids' sleep patterns as well.
More specifically, parental marital instability -- and all the stress and strife that goes with it -- when a baby is nine months old is linked to poor sleep behavior even nine months later. These new findings suggest babies are able to internalize parental discord before they are able to cognitively understand its implications.
The Huffington Post spoke to head researcher Anne Mannering, faculty at Oregon State University, about the implications of this study.
Of 357 participating families in this study, all of the babies were adopted. Why did you choose to focus on adopted children?
For this study, being able to work with the adoptive families was beneficial because it allowed us to rule out the possibility that any associations we might find between the parents' behavior and the children's behavior would be due to shared genes.
How exactly did you determine whether parents' marriages were volatile or not?
We specifically focused on marital instability, which is not the same as looking at things like conflict or arguing or something like that. The types of questions we asked were whether or not each partner had considered separating or considered divorce. And we looked at that over time, so, [we asked] have you considered this over the past year or within the last three months, for example. Based on their answers to five questions like that, we came up with a measure of their instability.
Are their degrees of volatility in a marriage, and did you see that play out in the sleep patterns -- i.e. the more volatile the marriage is, the worse the effect on sleep?
First, just for our study, what we did find was that higher levels of instability in the marriage predicted higher levels of sleep problems later on. So marital instability at nine months predicted poorer sleep at 18 months for the toddlers.
Other studies have looked at the level of conflict in the marriage, and what it suggests is that the more intense the conflict it is, the more frequent it is, particularly if it is unresolved, that is associated with more negative outcomes for children that can be associated with sleep, that can also be associated to emotional or behavioral problems.
Another thing that is unique about our study is that we looked at these issues for instability in the marriage and child sleep pretty early in development compared to some other research. We already know that the marital relationship can predict sleep problems for older kids.
Why did you choose to compare babies at 9 months and 18 months instead of, say, 6 months and 12 months? Is there something significant about those months in terms of a baby's development?
Well, part of it has to do with the periods of time in which we had information from the families. So we measured marital instability at 9 and 18 months.
Part of it also had to do with looking at a nice window of time where we know that sleep patterns are getting more regular for infants and toddlers. So they should be able to sleep for longer periods and have fewer transitions that require a parent to come and help comfort them. So that's a good period to look at whether stress in the family impacts sleep regulation.
You did not find that kids' poor sleep led to increased marital instability. That seems to run counter to research about babies affect on marriages. Were you surprised?
We were somewhat surprised. We were expecting potentially to find a reciprocal relationship there so that marital instability could impact child sleep, and that child sleep might also relate to marital instability. And in our sample for the families we looked at and the time period we looked at, we did not find that child sleep problems at nine months predicted marital instability at 18 months. That could be again due to the particular time we looked at or maybe something about the particular families—I agree, that definitely other studies have shown that especially during that transition to parenthood the sleep deprivation that parents often experience can be related to changes in marital satisfaction.
What are the implications of poor sleep patterns -- falling asleep, staying asleep or frequent night waking -- on a child’s development?
In our particular study we can't talk to longitudinal effects of most children at this point. Other researchers have looked at this question and several studies have shown that poor quality of sleep over time can predict problems academically, behavior problems and emotional problems. Sleep problems that develop early tend to persist over time and are particularly related to these particular outcomes.
Most of the families that participated were white, middle class and affluent. How might this have skewed the data?
We know that it's important to take into account other factors. Socioeconomic status, cultural factors related to routines around childhood sleep and bedtimes, all of those things we were not able to look at specifically in our study. We do know that our sample is similar to other studies that have looked at adopted families, but absolutely we wouldn't want to try to generalize beyond the particular families in our studies. More research would need to be done.
What can parents who are having marital problems during their kids' early years take from this research? If they have to fight, should they do it out of earshot of their kids? Or would that even matter?
Well I think part of it is just a more general statement of being aware that stress within the marital relationship may be impacting children earlier than parents would expect. So, for example, being able to understand cognitively that your parents are having an argument may not be necessary for a child to be effected by that level of stress in the environment.