Let's dive into some of the theoretical approaches to temperament in psychology. This may seem boring to some of you, overly-simplistic to others (I'm often in this camp), or just plain irrelevant to those of you suffering through intense sleep deprivation. All fair criticisms, I think. But I'd like to just get a few ideas out about the broad temperament styles before we all start to concretely speculate about their implications for children's sleep. If nothing else, this post will make you thankful that you skipped that application to grad school in developmental psychology.
I mentioned in Part I of this series of posts on temperament that there are many ways to divide the pie of temperament, and many books have been written on the subject. One of the original systems for delineating temperament styles in infants and young children was developed by Thomas & Chess in the 60s and 70s. It's what I like to call the "three little bears" approach (too hot, too cold, juuuuuust right kinda thing). Here's a reasonable summary of their research approach, the methods they used to categorize kids, and some of the conclusions they came up with. (It's more complex than I can give credit to in a blog post.) According to these researchers, of the children who could be classified, about two-thirds were labeled “easy” and the remainder were divided almost equally into “difficult” and “slow to warm up.” The easy child adapted smoothly to new experiences, was generally happy, and had few difficulties eating or sleeping. Difficult babies were irritable, fussy, and reactive, they generally cried a lot, and they tended to have irregular eating and sleeping habits. Babies who were slow to warm up would often withdraw from new experiences or people, and they adapted to these experiences only slowly, after repeated exposure. The first groups of children, easy and difficult, probably bring clear images to mind for anyone who’s spent time with children. Indeed, some babies seem to take challenges and novel experiences in stride, whereas others fuss and cry when they are challenged, when their expectations aren’t met, or when they are tired, or hungry, or just plain moody. The "easy" group grow into toddlers who, though rambunctious and defiant to some degree, generally end up cooperating with parents and accepting most situations. Difficult toddlers, on the other hand, can be extremely challenging. They are the ones for whom nothing seems to work, for whom every choice is intolerable, and who fight or resist many parental directives, from putting on their socks to eating what’s in front of them (or eating anything at all except jellybeans and olives). They're also often the ones who are "overly" sensitive to certain foods and to unfamiliar textures, and so on.
The final group, "slow to warm up", seems to apply to children who were more precisely described by Jerome Kagan’s research in the 80s (he's recognized as one of the most prominent developmentalists in the field; he's controversial and damn interesting to boot). Kagan delineated a group of babies who would freeze or withdraw when faced with loud noises, novel sights, and new people. He described these babies as anxious or inhibited. These anxious/inhibited children generally showed a high, regular heart-rate and they would startle very easily and quickly. If we compare “difficult” babies’ and these anxious/inhibited ones, the difficult babies' temperaments seem to revolve around the emotion of anger — they react to many of their challenges by throwing fits of rage or they are often in an angry huff when things don't go their way. But inhibited babies’ predominant emotion is anxiety or fear. They react to strangers with intense shyness, they are often afraid of anything remotely risky (dipping a toe in the water, loud traffic, crawling too far, but especially interacting with new people).
Now remember, I'm referring to infants and young children (we tend to think about temperament as "personality" after early childhood). So what happened to the anxious/inhibited kids when they grew up? A certain proportion of these babies would grow into inhibited, overly-cautious teenagers and adults, a few would develop full-blown anxiety disorders, but the VAST MAJORITY would end up just like most other children, with no real emotional problems at all. So let's be clear here: No one is suggesting that early, biologically-based temperaments do not or cannot change with particular types of EXPERIENCES and exposure to particular environments. Nature and nurture are inseparable and suggesting one trumps the other is silly (it's my blog so I get to say these kinds of sweeping generalizations. And you can — and SHOULD — tell me I'm wrong if you think so).
So these are some of the VERY basic ways that the temperament pie has been sliced. MANY other systems of classification have been put forward as well, of course, but a surprising number don't differ significantly from these basic types. So how does this all relate to sleep? Well, that's the trouble: I don’t have enough information/data/research to suggest a particular approach to sleep training based on children’s temperamental traits. There’s simply no empirical research that has tried to identify the best match between different temperamental styles and different sleep training approaches, nevermind matching these different styles to the best TIME to sleep train. However, we can speculate, (and Marc and I did, in the book) why certain children with various temperaments might respond better or worse to some sleep training strategies administered at certain periods in development.
What are some of your best guesses? How do you think your chid's temperament has influenced his sleep habits? Did you change your mind about the methods or the timing of sleep training when you understood your child's temperament better? Do you think that one particular method or one particular stage to sleep train is most appropriate for all kids, no matter their temperamental style?