Thank you for your fascinating question.
In any type of parenting, there are going to be many different
factions disagreeing on what to do and what not to do. There are some
studies I will present you with that have studied extinction and find
it harmless, and even find that it improves a child's emotional life,
as they get more peace and rest at night.
However, I have found some scientists who believe that the "extinction
method" is damaging to a baby's health and brain development, and
finally I have found contradicting studies that show that the
eradication of sleep problems (which would result if you put the
extinction method into place) helps the entire family, both children
and parents, to be calmer and healthier and live a more peaceful life.
Who is right?
I believe that the studies that show that there is no harm seem to be
correct-- they are controlled studies done on a scientific basis.
The studies which are used on anti-extinction websites to contradict
the practice all have a common problem.
In the studies that support the idea that babies who are allowed to
"cry it out" will later have development problems, the researchers
merely research how CRYING affects a child later in life-- in other
words, they assume that a baby who "cries it out" will spend more of
her infancy crying than a baby that is comforted when she cries.
However, as Richard Ferber and many "cry it out" experts detail, the
point of using the CIO method is to stop your baby from crying in the
future. Babies who are comforted when they cry will continue to cry
any time they feel like it and want their parents to comfort them, so
in the end they may cry more than babies under the CIO method,
resulting in more developmental damage. I could not find a
double-blind, controlled study that said that the CIO method caused
more damage than the attachment method.
I found some studies which confirm that infants who are allowed to cry
rather than be comforted immediately will end up crying less. One
could take that to mean that the arguments of the scientists who say
"crying it out" is bad because of the harsh effects that crying has on
babies' development are geared to the wrong theory-- that in fact,
"crying it out" results in an end result of crying less, so it results
in better brain development than the attachment method. Under the
attachment theory, the babies will cry more and have improper brain
development. I also found two studies that said that responding to a
baby's cries causes them to cry less, while another says they cry
more. When scientific studies contradict each other, one must go
through the articles and examine them for mistakes or inconsistencies.
One factor in these studies that are used for anti-extinction purposes
is the definition of "maternal responsiveness." Some mothers are not
responsive at all and would let their children cry all day without
being attended to. When extreme results have been found in a study--
for example, that babies with mothers with low response rates later
suffer ADHD or lower IQs-- this generally assumes that the babies'
mothers had EXTREMELY low response rates to cause the baby to suffer
an attachment disorder. (And in many cases, children who are
completely abused or neglected never even develop an attachment
disorder-- so I don't think you have anything to worry about.) Never
in any of these studies is a mother who attends to the baby during the
day and lets him/her "cry it out" at night shown to have caused an
attachment disorder. If you are a stay-at-home mother who spends most
of the time with your baby during the day, you are certainly a
responsive mother no matter what you do at night. There has not been
a study covering this particular instance. I'm not sure why, other
than that it would be difficult to have a controlled study, as babies
are all different and experience different emotions and crying levels.
There are many books and websites which claim that studies have been
conducted on these levels, but they are wrong. They will cite studies
that say that babies' stress levels cause them later damage, or the
amount of crying cause them later damage-- but as the following
studies establish, babies who are "ignored" will cry less than babies
who are not.
Here are these studies:
"Are infant crying and maternal responsiveness during the first year
related to infant-mother attachment at 15 months?"
Authors: Van Ijzendoorn M. H.; Hubbard F. O. A.
Source: Attachment & Human Development, 1 December 2000, vol. 2, no.
3, pp. 371-391(21)
"Contrary to our expectations, the more frequently mothers ignored
their infants' crying bouts in the first nine-week period, the less
frequently their infants cried in the following nine-week period, even
if intervening variables like earlier crying and synchronous
responsiveness were controlled for. 'Benign neglect' of fussing may
stimulate the emergent abilities in infants to cope with mild
"Matemal Unresponsiveness and Infant Crying Across the First 9 Months:
A Naturalistic Longitudinal Study"
FOA HUBBARD, MH VAN UZENDOORN - INFANT BEHAVIOR AND DEVELOPMENT, 1991
"More frequent delay of maternal responses reduces the number of
crying bouts during the first half year of life."
This study's results clash with those of the above studies.
"Infant Crying and Maternal Responsiveness"
Silvia M. Bell, Mary D. Salter Ainsworth
Child Development, Vol. 43, No. 4 (Dec., 1972), pp. 1171-1190
"Nevertheless, maternal effectiveness in terminating crying was found
to be less powerful than promptness of response in reducing crying in
A critique of the above Bell/Ainsworth study was published, finding
their conclusions to be unsupported by their data.
"Does Maternal Responding Imply Reduced Infant Crying? A Critique of
the 1972 Bell and Ainsworth Report"
Jacob L. Gewirtz, Elizabeth F. Boyd
Child Development, Vol. 48, No. 4 (Dec., 1977), pp. 1200-1207
"It was concluded that Bell and Ainsworth's main conclusion, that
maternal responding implied a reduction in infant crying, was not
supported by their data."
There is a book by Margot Sutherland called "The Science of Parenting"
in which she claims that leaving a baby to cry will cause harm in
their brain's development process. She also claims that all children
should sleep with their parents until the age of five. What she does
not account for, however, is the concept that co-sleeping and other
such activities (such as comforting the baby multiple times in the
night) can cause damage in the child's parents' marriage, which could
eventually contribute to divorce or marital difficulty. There are many
studies on how divorce affects children in a negative way and most
people are very familiar with that idea. So in a way, this seems to be
a no-win situation. While I couldn't get a copy of Sutherland's book,
from the online reviews of it, while she claims to base her ideas
wholly on science, she doesn't always do so. For instance, she cites
a study which indicates that traumas in a young life can cause babies
to develop smaller brains than those who do not have trauma as a
reason to comfort your baby when they cry at night. But is a baby that
suffers trauma for a few weeks by "crying it out" any less traumatized
than a baby that suffers for months or longer when he/she tries to go
to sleep by him/herself and can't because Mom is not right there? Is
the five-year-old duly traumatized when he has never slept alone and
is suddenly expected to? Her claims do not seem to me to be backed by
solid scientific evidence.
When the researchers authored these studies citing trauma in a baby's
life as causing smaller brain development, they studied babies who had
been continuously traumatized by abuse and neglect, not babies who had
simply spent a few nights in the crib alone.
I don't find any scientists or supporters of these specific theories
other than Margot Sutherland herself. There are many scientists and
researchers who approve the attachment theory over the Ferber method
(and I have linked to some of their websites in the "Sources" section)
but none of them could present a study that contradicted the findings
that other studies found, that extinction does not cause harm but in
fact is good for the baby's well-being. Many of them cite studies on
the two factors I mentioned above: amount of crying and level of
maternal responsiveness, which do not truly deal with the issue at
This study concludes that the extinction method works better than
non-extinction for the baby.
"Behavior Characteristics and Security in Sleep-Disturbed Infants
Treated with Extinction"
Karyn G. France
University of Canterbury
Journal of Pediatric Psychology 17(4) pp. 467-475, 1992
"Measured and compared the behavior characteristics and security
scores of 35 infants (6?24 months) treated with extinction for sleep
disturbance with those of 13 untreated and 15 normal sleep controls.
There was no evidence of detrimental effects on the treated infants
whose security, emotionality/tension, and likeability scores improved.
The findings are congruent with those from a previous study with
preschoolers and have important implications for the prevention of
later behavior problems in sleep-disturbed children."
This study finds that higher cortisol (a hormone which is released
when a baby is stressed) level results when infants have low
attachment levels with their parents. I link to it because it is often
cited by anti-extinction proponents as proving that extinction causes
higher levels of cortisol. But this study does not prove in any way
that extinction itself causes low levels of attachment, so the study
is misrepresented on most of those sites.
"Stress reactivity and attachment security"
Megan R. Gunnar 1 *, Laurie Brodersen 1, Melissa Nachmias 1, Kristin
Buss 2, Joseph Rigatuso 3
1Institute of Child Development, University of Minnesota, Minneapolis, Minnesota
2Department of Psychology, University of Wisconsin, Madison, Madison, Wisconsin
3Department of Pediatrics, University of Minnesota Medical School and
Health Partners, Inc., Minneapolis, Minnesota
"... Salivary cortisol, behavioral distress, and maternal
responsiveness measures obtained during these clinic visits were
examined in relation to attachment classifications... In the 2nd year,
the combination of high fearfulness and insecure versus secure
attachment was associated with higher cortisol responses to both the
clinic exam-inoculation situation and the Strange Situation. Thus,
attachment security moderates the physiological consequences of
fearful, inhibited temperament. Regarding the 2-, 4-, and 6-month
data, later attachment security was related to greater maternal
responsiveness and lower cortisol baselines. Neither cortisol nor
behavioral reactivity to the inoculations predicted later attachment
classifications. There was some suggestion, however, that at their
2-month checkup, infants who would later be classified as insecurely
attached exhibited larger dissociations between the magnitude of their
behavioral and hormonal response to the inoculations, Greater
differences between internal (hormonal) and external (crying)
responses were also negatively correlated with maternal responsiveness
and positively correlated with pretest cortisol levels during these
early months of life."
This study found no relation between levels of attachment and levels
of stress and levels of cortisol.
"Attachment, Temperament, and Adrenocortical Activity in Infancy. A
Study of Psychoendocrine Regulation."
Authors: Gunnar, Megan R.; And Others
Descriptors: Age Differences; Attachment Behavior; Infants;
Journal/Source Name: Developmental Psychology
Journal Citation: v25 n3 p355-63 May 1989
"Examined relations among adrenocortical stress reactivity, infant
emotional or proneness-to-distress temperament, and quality of
attachment in 66 infants tested at 9 and 13 months. Adrenocortical
activity was not associated with attachment classifications.
Significant only at 9 months, elevations in cortisol were small."
This study found that babies (and parents) were happier and healthier
after an ignoring treatment, and the babies cried much less than their
"Treatment of Young Children's Bedtime Refusal and Nighttime Wakings:
A Comparison of ?Standard? and Graduated Ignoring Procedures"
Journal of Abnormal Child Psychology
"Following treatment, only positive side effects were observed. When
compared to the wait-list group, mothers in the standard ignoring
group reported less verbose discipline and decreased stress in
parenting, while mothers in the graduated ignoring group reported
improved parent?child relationships. Treatment gains were maintained
over a 2-month follow-up period."
Here is a good study that may shed more light on your topic. It
doesn't go into complete detail in the abstract, so you'll have to
read through the full text to comprehend the results. The study found
that ignoring had better results after one week but both methods had
the same results after two weeks (conflicting with the above study).
"Reducing Nocturnal Awakening and Crying Episodes in Infants and Young
Children: A Comparison Between Scheduled Awakenings and Systematic
PEDIATRICS Vol. 81 No. 2 February 1988, pp. 203-212
Vaughn I. Rickert PsyD and C. Merle Johnson PhD1
"Empirically supported treatments in pediatric psychology: bedtime
refusal and night wakings..."
J Mindell - Journal of Pediatric Psychology, 1999 - us.oup.com
Harvard University Gazette
"Children Need Touching and Attention, Harvard Researchers Say"
'"Parents should recognize that having their babies cry unnecessarily
harms the baby permanently," Commons said. "It changes the nervous
system so they're overly sensitive to future trauma."'
Here is the "study," which is not really a research study but a
comparison of two cultures. As far as I can see, no proof is given
that American children are worse off than the Kenyan children they're
compared to. These Harvard researchers may have a point, but they do
not prove it and they never conducted a comprehensive study to prove
it (I don't know why not) and so their results can only be taken as
advice, not science. I really see no backing for their conclusions.
Here is their paper so you can judge for yourself.
"Emotional Learning in Infants: A Cross-Cultural Examination"
This study finds that levels of cortisol are raised in stressful
situations, such as a parent leaving.
"Urinary cortisol excretion rates and anxiety in normal 1-year-old infants"
K Tennes, K Downey and A Vernadakis
Psychosomatic Medicine, Vol 39, Issue 3 178-187, Copyright © 1977 by
American Psychosomatic Society
This study found that crying actually created an amnesiac effect, in
which babies over the long-term forgot what they were crying about in
the first place.
"The Effect of Crying on Long-Term Memory in Infancy"
Jeffrey W. Fagen, Phyllis S. Ohr, Lori K. Fleckenstein, Dena R. Ribner
Child Development, Vol. 56, No. 6 (Dec., 1985), pp. 1584-1592
"The influence of crying on infants' long-term memory for a learned
response was investigated in 3 experiments. In each, infants were
trained to move a crib mobile containing 10 identical objects by means
of kicking and were then exposed to a reinforcer containing only 2 of
these components. This shift in component numerosity produced crying
in 53% of the infants. Infants who cried in response to the reward
shift evidenced no retention of the contingency 1 week later
(Experiment 1) but did have excellent retention at 1 day (Experiment
2). In Experiment 3, a brief reactivation treatment alleviated
forgetting at 3 weeks regardless of the presence of crying in response
to the change in mobiles. An unexpected recency effect characterized
the efficacy of the reactivation treatment. The results indicate that
crying in response to the violation of a reward-expectation habit
functions as an amnesic agent to produce accelerated forgetting."
According to this study, the well-being of families (both parents and
children) improves after using the extinction method.
"Treatment of sleep problems in families with young children: effects
of treatment on family well-being."
* Eckerberg B.
Department of Paediatrics, Falun Hospital, Falun, Sweden.
"CONCLUSION: If parents experience young children's night awakenings
as a problem, teaching the children to fall asleep by themselves
usually solves this problem quickly. According to parental ratings,
family well-being and negative daytime behaviour are also improved."
This article recommends early intervention in sleep problems and that
children whose sleep problems are not dealt with will most likely
continue to have sleep problems in ongoing years.
Journal of Pediatrics
* Kataria S,
* Swanson MS,
* Trevathan GE.
Allen Schore's research focuses on cortisol levels and how they raise
in the event of trauma, such as crying. He says that the caregiver
coming in to soothe crying reduces the levels of cortisol. (A
counter-argument to this would be that if overall crying is reduced by
"crying it out" as some studies show, cortisol levels would be low in
the first place and there would be no need for the caregiver to soothe
in order to lower them.)
"Brain Development, Attachment and Impact on Psychic Vulnerability"
"By regulating affect, the caregiver is also regulating the release of
neurohormones in the infant's brain. High levels of cortisol, a stress
hormone that may well be released in the brain during states of
distress, has been shown in some animal studies to destroy synapses.
In the inevitable event of distress states in the infant, the
caregiver's moving in to repair the connection and comfort the infant
reduces the levels of cortisol and related stress hormones. As a
result, the frontal cortex develops a greater concentration of
glucocorticoid receptors that can modulate stress responses (Schore,
When there is no interactive repair; when the caregiver is abusive,
neglectful or continually misattuned, infants may remain in
chronically negative states, their corticosteroid levels chronically
elevated. This results in a reduction in the number of synapses, even
the death of neurons, according to Schore's hypothesis."
"The effects of early relational trauma on right brain development,
affect regulation, and infant mental health"
Allan N. Schore *
Department of Psychiatry and Biobehavioral Sciences, University of
California at Los Angeles School of Medicine
email: Allan N. Schore (email@example.com)
"In the following, I offer thoughts on the negative impact of
traumatic attachments on brain development and infant mental health,
the neurobiology of infant trauma, the neuropsychology of a
disorganized/disoriented attachment pattern associated with abuse and
neglect, trauma-induced impairments of a regulatory system in the
orbitofrontal cortex, the links between orbitofrontal dysfunction and
a predisposition to posttraumatic stress disorders, the neurobiology
of the dissociative defense, the etiology of dissociation and
body-mind psychopathology, the effects of early relational trauma on
enduring right hemispheric function, and some implications for models
of early intervention."
Dr. Schore mentions that abuse and neglect harm a child, but he does
not mention a normal "crying it out" method in his abstract.
Here is another source on Schore, that again mentions abuse and
neglect (not normal parenting) as a direct catalyst in infant
Our Baby Forum
"Dr. Allan Schore of the UCLA School of Medicine has demonstrated that
the stress hormone cortisol (which floods the brain during intense
crying and other stressful events) actually destroys nerve connections
in critical portions of an infant's developing brain. In addition,
when the portions of the brain responsible for attachment and
emotional control are not stimulated during infancy (as may occur when
a baby is repeatedly neglected) these sections of the brain will not
develop. The result is a violent, impulsive, emotionally unattached
child. He concludes that the sensitivity and responsiveness of a
parent stimulates and shapes the nerve connections in key sections of
the brain responsible for attachment and emotional well-being."
Another link from the Our Baby Forum is this study by Michael Lewis.
"Infant, Mother, and Mother-Infant Interaction Behavior and Subsequent Attachment"
Michael Lewis, Candice Feiring
Child Development, Vol. 60, No. 4 (Aug., 1989), pp. 831-837
Here is the description from the forum:
"Infant developmental specialist Dr. Michael Lewis presented research
findings at an American Academy of Pediatrics meeting, concluding that
the single most important influence of a child's intellectual
development is the responsiveness of the mother to the cues of her
I don't see anything involving that in the abstract, but you may want
to get this study and read it yourself.
"Modifications of Systematic Ignoring in the Management of Infant
Sleep Disturbance: Efficacy and Infant Distress"
Karyn G France, Neville M Blampied. Child & Family Behavior Therapy.
New York: 2005.Vol.27, Iss. 1; pg. 1
"Systematic ignoring and two modifications of it (systematic ignoring
with minimal parental check and systematic ignoring with parental
presence) were evaluated for treatment of Infant Sleep Disturbance
(ISD). Fifteen infants (6-15 months of age) participated in a study
utilising a multiple-baseline design across the three treatment
programs. Frequency of awakening and duration of crying were measured
in order to evaluate treatment efficacy and infant distress. All
programs led to decreases in night waking but infants treated with
systematic ignoring with minimal check woke and cried more over the
treatment period. Given our present knowledge, the parental presence
program appears to be the treatment of choice. This result needs
further investigation, as do those of other programs commonly used to
treat Infant Sleep Disturbance (ISD) in infants. [PUBLICATION
Natural Child Project
"Emotional Learning in Infants: A Cross-Cultural Examination"
Almost all of the papers cited in this bibliography are not available
on either Google Scholar or other journal search engines, so most of
them can't be accessed to see what they say and if the claims are
National Child Traumatic Stress Network reading list
DeBellis M, Baum AS, Birmaher B, Keshavan M, Eccard CH, Boring, AM,
Jenkins FJ, Ryan N.
(1999) Developmental Traumatology Part I and II: Biological Stress Systems.
45:1259-1270 (Part I) 1271-1284 (Part II)
"The Science of Parenting"
by Margot Sutherland
"Becoming Attached: First Relationships and How They Shape Our
Capacity to Love (Paperback)"
by Robert Karen
This BabyCenter article mentions taking an approach that involves
coming in to comfort the baby, but not co-sleeping and not comforting
them for extended times, but simply every once in a while so that they
know you're there for them.
"Ask the Experts:
Are we damaging our baby by letting him cry himself to sleep?"
"Children 'should sleep with parents until they're five'"
"Science shows up Supernanny"
Controlled Crying Position Paper
"Mothering Matters: Throw Away Your Cry-It-Out Manuals"
"The Crying Child~ Resources about CIO"
Partners in Parenting blog
Anything but "Good for Their Lungs""
"Stress in Infancy"
by Linda Folden Palmer, D.C.
University of Michigan Pediatrics
"The Ferber Method Helps Some Children Sleep Longer"
"Behavioural and cognitive-behavioural interventions for sleep
disorders in infants and children"
JL Owens, KG France, L Wiggs - Sleep Med Rev, 1999 - tau.ac.il
(on Google Scholar, scholar.google.com)
extinction method infants
"no-cry sleep solution"
fagen ohr fleckenstein
miller commons kenya
crying it out attachment
michael lewis responsiveness
cry it out cortisol
site:amazon.com science of parenting
m debellis biological psychiatry
margot sunderland crying it out
site:amazon.com becoming attached
cortisol crying it out
"infant sleep disturbance"
There are studies which prove that the extinction method makes a baby
happier, with more rest, and does not create an attachment disorder.
This is despite the many websites that proliferate on the attachment
method and saying that the Ferber method has been proven wrong by
studies. I never saw one conclusive study that was put forth by any of
these sites and most are simply based on either pseudoscience or on a
false premise-- the idea that Ferberization results in more crying,
when studies show that it results in less crying in the long run.
Many of these sites promote the idea that extinction is bad for a
baby's health because crying, trauma and stress prevent the baby's
brain from proper development. However, it is actually the attachment
method which causes babies to cry the most and from which they would
experience these symptoms of improper brain development. I would try
the extinction method if you can and see if it makes your family's
lives better. If it doesn't work, you can try the attachment method.
If you need any additional clarification, let me know and I'll be glad
to assist you.