If you have not already done so, please read Blog Posts 1 through 5 that describe how sleep is important and beneficial. I will post specific information for parents and children based on my book, “Healthy Sleep Habits, Happy Child.” Please do not be put off by my book’s length. This is a reference book. Read only the topic of interest to you.
Rúna Sif Stefánsdóttir is a sleep and health researcher in Iceland. She began her PhD studying how adolescents sleep and how sleep affects cognitive performance. Then she became a mother — and discovered that understanding sleep scientifically and implementing healthy sleep in a real household, in a real culture, with real exhaustion, are two entirely different things.
Her account spans six years, two daughters, and a gradual, honest reckoning with what it takes to prioritize sleep when everything around you — culture, schedules, the Icelandic summer sun, extended family dinner habits, and a toddler who wants to stay at the party — is working against it.
The Latest Update: Two Very Different Children
“Elísabet is 6 years old and a few months, and Natalía is turning 3 years old in just a few days. The last two years have been absolutely crazy. I never knew you could have kids, a few years apart, same parents and same household, and they would be absolutely black and white. This has been a large learning curve for my husband and me.
Elísabet has been following the early bedtime routine quite well the last few years. She likes going to bed early, and we notice that all the work regarding her sleep that we put in those early years has been beneficial. Now that she is slightly older, we moved her to her own bedroom and she reads on her own before sleep — we sit with her for a little bit and most days she goes to sleep on her own. Of course, there are days where she wants more attention, and some days her little sister is allowed to sleep in the big bed with her. She falls asleep around 7:30pm in winter, but closer to 8:30 in summer — there is just more daylight and it is harder to follow any light cues. She usually sleeps until at least 6:30, even 7:30, if her sister doesn’t wake her up.
My husband and I started dividing nights — he would put her to sleep one night and I would do the next. We found this helpful and she got into the routine quickly. It also helps with the mental load of bedtime, so it is not always the same parent. All in all, we are quite happy with how we have dealt with Elísabet’s sleep and where she is today. Even when she is allowed to play a little longer with friends or stay up later with the grandparents, she returns to routine quickly.
Our biggest headache the last two years has been Natalía, the younger one. It was a hectic time for my husband and me at work when she was born, and we never had enough time — and I think we just didn’t have enough energy or patience — to deal with her sleep. From early on it was clear that she wanted to sleep close to other people, and she did not sleep a single night in her crib. She has more or less been co-sleeping with us since birth. When she was about 18 months and I stopped breastfeeding, we moved her to Elísabet’s room, and they slept together in a bunk bed where the bottom bunk was a larger bed so we could lie with her until she fell asleep. That worked quite well, but she could never fall asleep on her own. She also wakes up every night and comes to our bed — and always has.
Another aspect we never dealt with well enough was that Natalía, regardless of age, was on Elísabet’s sleep schedule and routine. That was fine at first, but now Elísabet is older and Natalía is only 3 — she needs to be going to sleep closer to 6:30pm, not 8pm. We moved Elísabet to another room, but someone still needs to go to sleep with Natalía, and thus Elísabet feels left alone, and it just ends up being easier putting them both to sleep at the same time.
The next steps are to start following the drowsy signs for Natalía and trying to figure out how to get her to bed even though Elísabet is still awake. We tried doing that on days when my husband was home early from work, but we need to make it a routine. I have found that making sleep a priority with the second child is a lot harder than with the first, and also trying to pay attention to both of them. There are also other activities that get in the way — for instance, Elísabet has soccer practice from 5:30 to 6:30pm once a week, and then it is impossible to try and have an early routine. Natalía is also a child who likes to be included — she is the life of the party, wants to do everything the same as her sister, and she doesn’t want to miss out.
The biggest challenge will be to put them to sleep at separate times, especially since we have not worked on Natalía’s sleep at all. Now that Elísabet can fall asleep on her own, we might be able to focus more on Natalía’s sleep, even though both of us aren’t always home at bedtime.”
What This Update Illustrates
Rúna’s account is valuable precisely because it is honest about failure alongside success. Elísabet’s sleep story is, by now, a success. The early bedtime work done in those first years produced a 6-year-old who likes going to bed, returns quickly to routine after disruptions, and falls asleep independently. The investment compounded.
Natalía’s story is a different one — and a familiar one. The second child arrived when her parents were more exhausted, more professionally pressured, and already managing a toddler. The energy and patience required to work on sleep from the beginning was not there. Co-sleeping began out of necessity and became the only sleep context Natalía had ever known. She is now 3 years old and has never fallen asleep independently.
The Second-Child Problem
This pattern — healthy sleep established well for the first child, and substantially neglected for the second — appears across many consultations and many cultures. It is not a failure of love or knowledge. It is a failure of bandwidth. Parents of second children are simultaneously less rested, less resourced, and more experienced — which means they know what is happening but often lack the margin to address it in the moment it would be most effective.
The result is that by the time the second child’s sleep becomes untenable, the habits are more deeply ingrained and the correction more difficult. Natalía at 3 has three years of co-sleeping and parental presence at sleep onset behind her. The path forward is real but longer than it would have been at 4 months.
The Cultural Layer
Iceland’s late bedtime culture, the endless summer daylight, extended family dinner schedules, and a partner whose professional work falls in the afternoons and evenings — these are not excuses. They are genuine constraints that any sleep solution must account for. Rúna has navigated them by reorganizing the family’s afternoon, moving dinner earlier, letting some social occasions go, and accepting that the summer months will always be harder.
Her own conclusion, offered to other parents, is worth preserving exactly as she wrote it:
“The biggest advice I would give to other parents is that it is worth it. The mornings she sleeps longer are the ones when she goes to bed earlier, and she wakes up so much fresher, in better mood, and just more balanced. The ‘sacrifices’ of social things or activities just aren’t worth the 6am wakeup call or screaming because she is too tired.”
All families. All cultures. One biology.
— Marc Weissbluth, M.D.
