Thank you all for your thoughtful comments and emails on the last few posts. They have me newly inspired to think about research in areas that have not been touched by developmentalists yet. For this last post about temperament (at least the last for a while), let's think more explicitly about how it may apply to sleep training. I suspect that most of you will be disappointed with the lack of firm guidelines or precise advice that I'm about to give. That's because there's NOTHING out there in terms of good research that has looked at what is the best match between particular child temperaments and particular sleep-training methods. NADA. And I suspect well-designed studies on the subject will NEVER be conducted. Let's just imagine what that would take. It's making my head explode just thinking about it. You'd have to randomly assign families with children who are more "temperamentally sensitive" to a "cry-it-out" group, or a "no-cry training approach" group or a "don't do anything" group. Then you'd have to get families with "easy" kids to be assigned to the same 3 sleep-training groups and do it all over again with "slow-to-warm" or whatever categories you're working with. What parent with a child with ANY temperament will go through with a sleep method they don't think is working for their kid? How can you force this random assignment to stick and for families to go through it. You can't, basically (or it would be very, very difficult and your sample would be horrendously biased). And of course some methods will have to be slightly modified (for ethical reasons, if nothing else) so that they're suitable for the child that cries until he throws up vs the child who doesn't even whimper when the mother leaves the room. And there are SO MANY other factors that could impinge on the "success" or "failure" of these temperament-method matches. WHOA!  But you're not here for a very bad version of a crash-course in Research Design, are you? Sorry. Let's move on.

So, we don’t have enough information from science to suggest a particular approach to sleep training based on children’s temperamental traits. But I think we can broadly consider certain social and emotional features of different types of temperaments that might be relevant to the decisions you make. A child with a "difficult" or more "anger-prone" temperament often becomes embroiled in pivotal issues towards which parent and child confront each other again and again. These emotional hot spots become difficult to navigate around in more sensitive stages in development. It’s the toddler’s JOB to be defiant, at least some of the time. But when a child is defiant most of the time, teaching ANYTHING, not only good sleep habits, can be hell. So I'd suggest dealing with the tougher sleep-training concerns early on with the more difficult kids, before they become entrenched battle zones (not that I have any data on this, but let's say, before the 18-month transition period). For every rule learned, there will be one less issue to fight about later on. This may be particularly important when it comes to bedtime. Difficult babies may have trouble developing regular sleep habits regardless of parents’ philosophies and efforts. That’s why it’s probably most important to get these kids into a regular, predictable bedtime routine as early as possible—definitely before the 18-month HUMUNGOUS cognitive and emotional stage transition (which has everything to do with NEGOTIATING rules and pushing on your boundaries). Also, I would suggest that the difficult, more rambunctious/rebellious kids are the ones you want to really make sure to sleep train during one of the stable developmental periods. You might get away with some slack with an easy kid, but difficult kids will need to take advantage of the less emotional, less challenging optimal windows for change.

Anxious-inhibited children, as described in Part II, won’t have difficulties in as many situations, but the situations that DO prove to be difficult will have a very particular flavour. These kids will have the most trouble dealing with new people and with separations. And these difficulties are likely to improve on their own with age. So, while they're still hyper-sensitive, try to keep these challenges to a minimum. This applies to a huge assortment of considerations including the types of playgroups you join, the ways you deal with daycare drop-offs, and so on. But with sleep, it means that it might be wise for the parent of an anxious-inhibited child to provide extra doses of love and nurturance when sleeping in any new or less-familiar context. This applies to all sorts of sleeping arrangements including spending the night at the grandparents' house, in hotel rooms, having cousins sleep over, napping at daycare and so on. In all these situations, the anxious child will need EXTRA emotional support, even if daily (and nightly) sleep habits at home are firmly established and are associated with no distress. These considerations will be especially important in those stages of development marked by separation distress. So I'm simply (and perhaps obviously) suggesting that you provide your anxious-inhibited child, or your highly reactive and hard-to-soothe child, with loads of familiarity and free access to his parents for protection and security, especially during the 8-11 month transition and the 18-21 month stage. Of course separation issues will create extra challenges for sleep training. So you should definitely avoid sleep training during these two stages. Instead, shoot for the stages of greatest individual autonomy and resilience: 5 – 7 months and 12 – 16 months (we give these stages specific names in the book, but I won't confuse you here). The 5- 7 month stage might be especially well-suited for sleep training these anxious children, as it comes before the child has ever experienced true separation distress. Finally, take care never to combine sleep training with prolonged parental absence or the presence of unfamiliar adults. In other words, it's probably best to not use any sleep-training method that requires you to leave the child alone, probably crying, for long periods of time. For this type of child, these extended separations from parents (often mom) can be immensely distressing and may not, ultimately, teach the child anything about healthy sleep habits. I would even go so far as to say that if you have a die-hard anxious/inhibited child, don’t even think about baby-sitters until after sleep training has settled into a stable and predictable habit.

Finally, if your child is best described as easy, emotionally resilient, less reactive, easily soothed, then relax! You’re going to have the easiest time with most social-emotional challenges, sleep training included. In fact, you might get away with deviating from the sug
gestions we gave in the book and I've given throughout this blog for the most optimal windows for sleep training. Of course, I'd still suggest sticking to our stage recommendations, but if uncontrollable events like returning to work, moving house, or dealing with another child make it difficult to schedule sleep training during a "stable" developmental phase, you’ll still have a reasonable shot at successful sleep training during non-optimal periods. And less serious consequences if things don’t work out.

Did you consider your child's temperament when you began thinking about what methods to use? Do you have an "easy" temperament child that you sleep-trained with no fuss smack-dab in the middle of one of the stages we DON'T recommend? Do you think there's one method out there to sleep-train that's appropriate for all temperament styles? Do you have any lingering questions about temperament you still want to discuss?