Extinction: Why Cry It Out is Extinct

I have argued before that no modern sleep expert recommends pure “cry-it-out” (CIO) sleep training. Here I want to explain in more depth where CIO stands currently. In order to simplify the discussion, I’ll call it by its more technical name, extinction. Some versions of this method are widely recommended today. One kind, unmodified extinction, has all but disappeared, or become extinct. That’s a shame, because it is highly effective, as I’ll explain below.

When it comes to any kind of human or animal behavior, “extinction” refers to the disappearance of a behavior in the presence of a stimulus. Pavlov famously could make his dogs salivate when he rang a bell (the stimulus). The dogs had learned that the bell meant Dr. Pavlov was about to feed them. That was only the first part of the experiment. In the second part, the dogs stopped salivating after a while. In other words, the salivating behavior “extinguished” with time.

Extinction in Sleep Training

When it comes to sleep training, the behavior we are trying to extinguish is crying. In sleep training, there are now three versions: Extinction with parental presence, graduated extinction, and unmodified extinction.

Extinction with parental presence is a version of CIO where the parent stays in the baby’s room, but does not respond to cries. With time, the caregiver moves farther away from the crib. Finally, the baby sleeps alone. This method has been championed by Kim West. She renamed the method “The Sleep Lady Shuffle”.  The terms get even more confusing because West’s followers refer to her method as “bedtime fading”. This is very different from true fading techniques.

The graduated variety is today better known as “Ferberization“. The method involves answering the baby’s cries, but doing so at longer intervals every night until the baby goes to sleep on her own.

Finally, we come to the true dinosaur, the unmodified CIO technique, sometimes called “cold turkey”. The villain of the CIO story is a late-19th century pediatrician named Luther Emmett Holt. The first time we see the words “cry it out”, they appear in Holt’s 1894 catechism “The Care and Feeding of Children.”

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Holt’s book is not a “sleep book”. In fact, there is no section on bedtime routines such as the kind we’ve grown used to. There is, however, a section on the types of infant cries and what to do about them. The section that follows is really about “problem crying”.

What should be done if a baby cries at night?

One should get up and see that the child is comfortable—the clothing smooth under the body, the hands and feet warm, and the napkin [diaper] not wet or soiled. If all these matters are properly adjusted and the child simply crying to be taken up, it should not be further interfered with. If the night cry is habitual some other cause should be sought.

How is an infant to be managed that cries from temper, habit, or to be indulged?

It should simply be allowed to “cry it out.” This often requires an hour, and in extreme cases, two or three hours. A second struggle will seldom last more than ten or fifteen minutes, and a third will rarely be necessary. Such discipline is not to be carried out unless one is sure as to the cause of the habitual crying.

Holt is describing a particular kind of crying here. This is crying born of habit. These are babies who have learned that crying can draw her parents’ attention. I suspect he is referring to babies who’ve acquired “object permanence“. That is, the baby knows that mom or dad is still there when they leave the room, and she can induce them to come back.

Dr. Holt is not describing a way to get a baby to fall asleep. He is describing a solution to a problem. That sleep problem is “bad sleep associations“. For example, the baby won’t sleep unless she has physical contact with a parent, or if she has a binky in her mouth. Likewise, sleep books that discuss “cold turkey” or any other CIO technique are aimed at families that already have developed bad sleep associations and want to reverse them.extinction 3

The Moa is Extinct. So is the Cold Turkey

Of the three types of extinction methods, only unmodified extinction, or cold turkey, has disappeared. It has ceased to be (see video below). And yet, cold turkey has been tested experimentally and found to be extremely effective. Several arguments agains cold turkey have been raised, not least that the method stresses the baby and caregivers. These objections have also been tested and so far have proven to be false. Even the most-cited article arguing for the negative effects of CIO  failed to show that the stress hormone cortisol goes up in crying babies!

The main reason cold turkey has gone extinct is that it is really difficult to listen to a child cry. Most parents can’t handle it. I know I couldn’t (the boys’ mother was the stronger partner). Listening to crying becomes even more difficult because of a thing called the “extinction burst”. This is an increase in crying as the sleep training process proceeds. Sometimes the burst happens after it appears that you’ve succeeded and the baby is sleeping through the night. In either case, the stress for parents becomes too much.

A second reason, perhaps more important, is that many parents believe cold turkey CIO will psychologically damage the baby. There is absolutely no evidence for this. To the contrary, the evidence suggests that babies sleep trained with unmodified extinction get good quality sleep. Parents report better sleep for themselves and their children. Overall there are only positive results for the family.

extinction 2
The reasons for the disappearance of a perfectly good sleep training method appear to be cultural, rather than scientific.

One more cultural factor deserves mention: consistency. Probably the number one reason why any of the extinction methods fails is that parents cannot or will not stick to the plan consistently. Consistency is the number one most important feature of any sleep training method, whether you are doing scheduled awakenings, bedtime fading, or the “Sleep Lady Shuffle” (which is, to repeat, extinction with parental presence).

To Extinguish This Line of Argument

  • The bottom line is that extinction methods are effective.
  • Extinction methods do not harm your baby or your bonding with her
  • Consistency, consistency, consistency. This is the essential piece of solving any sleep problem

Finally, let us explore the true meaning of life extinction with the help of our panel of experts, John Cleese and Michael Palin.