Introduction: A wise friend has told me more than once that “child development is not a linear process.” For example, teeth come in batches, often in fours separated by a few months of non-teething. As another example, just because Minnow is sleeping peacefully in her crib as I started to type this doesn’t mean that she will be a peaceful sleeper the next night. As a matter of fact, our journey toward the mythical sleeping through the night* has been anything but peaceful…and anything but linear.
Null Hypothesis: Child development, specifically duration of night-time sleep, is not a linear process.
Methods: The experiments consist of a time-series of observations on a single female infant, born January 26th, 2007. Treatments have consisted of co-sleeping, the no-cry sleep solution, an elimination diet to reduce allergens, and alternating periods of father and mother trying to put the infant to sleep, but never allowing the infant to “cry it out.” The infant has been exposed to an irregular series of changes associated with normal child development, a cross-country move, and her mother’s return to full-time work. There is no control infant, but meta-analysis of parenting literature and qualitative polling of other parents was conducted. (In non-technical terms: We’ve been co-sleeping with Minnow since birth, and we’ve generally been pretty happy with it, although it does have it’s occasional down-sides. But with my work demands and desire to to stay up past 8 pm most nights, we’ve been trying to get Minnow to go to bed for the night in her crib. Then when she wakes up I generally bring her to bed with me.)
Results: After a period of 10 months, the infant still wakes up fairly quickly, and sometimes refuses to be put down at all.
Figure 1. Day-time and night-time sleep of a single infant, excluding motion-induced car-seat sleep and sleep with a parent. Notice the non-linear progression.
For a while this fall, we were making progress. I could actually get most of a lecture written while she was asleep on her own. But in the last few weeks we’ve experienced a reversal of fortunes for reasons that aren’t all together clear to us (it’s not teething). Naps have also gone downhill, and we’ve become increasingly dependent on her falling asleep in the car on the way home from daycare, just so she gets one nap per day. (Those car-induced naps are not included in the figure.)
Discussion: An meta-analysis of the literature and informal polling of other parents suggests that the infant should be capable of sleeping much longer periods. Some other researchers suggest that infants as young as 3 months are sleeping through the night. We’re not entirely sure how to get future night-time data to have a consistently upward slope, but we hope that the end of the semester will provide me with some additional energy to focus on the problem. In the meantime, I’ve had 75 minutes of free night-time time in the past 3 days. 45 minutes were spent on housework and 30 minutes were spent reading email.
Conclusions: The study infant differs statistically signficantly from the average infant in her age group in terms of sleep duration, and has not exhibited consistent progress in lengthening sleep duration. Something has to change in the infant’s environment/stimuli for progress to be made and her mother to survive next semester. The null hypothesis is supported, child development is not a linear process.
*For those of you not in the know, “sleeping through the night” is defined as 5 hours.