What led you to studying infant sleep?
This interest stemmed from a wish to get a better understanding of how parents contribute to the development of infant sleep. Chronic sleep disruptions in children lead to chronic sleep disruptions in parents, which affects the parent-child relationship. I wondered, to what degree are daytime behavior problems the result of sleep disruptions or the result of problems in the parent-child relationship?
Could you share some details on how you measure sleep patterns?
We've used "watches" that measure sleep and wake activity in the children (actigraphs), daily diaries completed by parents, and general questionnaires about child sleep that the parent also completes. Although there is some association between what parents say and the actiwatches, the overlap is not as strong as one might think. Parents are able to report only on infant night awakenings that they notice. They miss the many wake bouts at night that the infant resolves on her/his own, without parental intervention.
What is one finding that surprised you the most?
We've reported in several papers that families who engage in persistent co-sleeping with the infant (co-sleeping that persists beyond 6 months of age) appear to be at risk for heightened family stress along a variety of domains. I was not expecting this and we have been trying to get a better understanding of why this is the case. It appears the persistent co-sleeping is not the cause of family distress, but could be a marker of it. This may be a finding that is particular to Western industrialized cultures in which solitary infant sleep is promoted over other sleep arrangements, but it flies in the face of the Attachment Parenting movement, which argues that prolonged co-sleeping is associated with better parent-infant relations and secure infant attachment. Our data do not support that claim.
One of the most interesting findings (at least I think so) is that maternal emotional availability predicts infant sleep more than bedtime routine. I can imagine exhausted mothers feeling that they are being blamed for their challenges. It's hard to be emotionally available if you are exhausted. What do you say to that?
Well, first I want to say that we never said that emotional availability promotes sleep more than a bedtime routine. What our 2010 paper said is that emotional availability was more predictive of infant night sleep quality than any single parenting practices (book reading, nursing, etc.). Emotional available parenting at bedtime, especially when coupled with a bedtime routine, likely fosters a nurturant, predictable sleep environment, which promotes the infant's ability to settle to sleep and, over the long run, to develop self-regulated sleep.
I understand the concern that an emotionally exhausted mother may find it challenging to be emotionally available. On the other hand, high emotional availability does not equate to being a perfect parent. A parent can be emotionally available if s/he is not hostile, not intrusive, and provides some structure to the bedtime. If a parent can simply be "good enough", that's probably all that is required to promote good infant sleep. And, of course, an exhausted mother can be spelled by a helpful father or partner, so that both work together on behalf of the baby.
What has surprised you the most about parenting?
I have three kids. What surprised me the most is how different they are, and these differences were noticeable from infancy onward. What also caught me off-guard is the different kind of parenting that was "pulled" from me in parenting my daughter, compared to both of my sons. I also developed an appreciation for the potential significance that fathers hold for girls, that I think is probably different than mothers.
P.S. Seeking to learn more about the findings reported by Doug's team, and especially about co-sleeping being a marker of family distress, I pored over several of his papers. His team installed video cameras in participants' homes and took continuous recordings of what occurred at bedtime and throughout the night. It turns out that mothers with higher depressive symptoms were more likely to bed share, which in turn appeared to actually disrupt infant sleep. Further, the group found that mothers were more likely to keep infants in bed sharing arrangements when they felt that they and their partners did not work together as a child-rearing team.
To me, these findings seem to suggest that when mothers' emotional needs are unmet, they may be attributing their own emotions to a crying child or trying to protect the child from the sadness they themselves are feeling. It is also possible that mothers are seeking out closeness and contact comfort with their infants to regulate their own distress. In either case, helping mothers feel loved, cared for, and understood, coupled with availability of counseling for depression, seems to be a big part of the solution.