Chapter 4 — Sensitive Periods:
the the crucial K-12 insight

A serializing of Growing Sustainable Children; and, Schools Worthy of Our Affection. This is my best guess how, in the next 100 years, whole-child K-12 schooling can evolve worldwide.

Bruce Dickson
17 min readNov 26, 2021


“Give children the right experience, at the right time, for the right reasons” ~ Adapted from Socrates, Plato, Aristotle

dg-pattern of sensitive periods (not exact) adapted from

I like to define “The Land of Childhood” as Nature’s programmed sequence of Sensitive Periods, for each child’s journey, birth to age 18. Each Sensitive Period opens like a blossom, at a particular time, for a particular period; after which, the blossom fades and retreats to a much less accessible state.

If you think about it, this was the original intuition for educating K-12 children. If you have enuf kids to separate into classes by age, do it. Multi-age classrooms, even small ones, are notoriously more work for teachers to facilitate.

It’s natural for young developing humans to organize themselves around their common developmental stages, their more intense receptivity to certain input and stimuli, their Sensitive Periods.

Consider the alternative, the full range of human capacities coming “online” all at once. This would necessitate educating be done oneo-n-one for every child, one teacher for every one child, K-12. How efficient would this be?

Sensitive Periods is the biggest, invisible, Unconscious Pattern, for teachers to know about. Period. They are relevant to every levels, pre-K-12.

A horse colt learns to walk within hours, a survival mechanism. A human child ideally learns to crawl first. Muscles are ready for walking around 18 months. No awareness in a physical-material body has a longer childhood. The first 18 years enable the sequence of Sensitive Periods to be laid out linearly, sequentially, rather than all occurring at once.

In this way, human children worldwide can adapt to 200 or more different cultures-languages. If all Sensitive Periods were present at birth, languages would be very different in ways hard to imagine.

Consider a flower gardener. When planning a large flower garden, the Gardener wants to see as much color for as many months of the year as possible. Therefore she deliberately selects and arranges plants who bloom at different times of the year, so the garden can appear colorful for more of the year. The Garden of Childhood is commonly imagined as the period between birth and puberty.

I also like the idea the above Plan for Sensitive Periods is by Angelic Design. The enduring coherency and workability of this Plan appears way beyond human design.

K-5 elementary Grades teachers are especially in the position of the flower gardener: What nourishment do my flowers need to thrill at this time, so when puberty comes, a magnificent blossom forms?

This brings us close to the Waldorf conception of Real Work for teachers, adapting curriculum content and methods to keep up with, engage and draw out, the calendar of each new Sensitive Period emerging in children.

Awareness of Sensitive Periods is not unique to Waldorf. Even Team Machine factory-style schools know something about this by way of Piaget. However, factory-style schools are characterized by only a cold, skeletal and abstract appreciation of children’s journey thru Sensitive Periods.

What’s needed prior to puberty is WARM appreciation of these periods, WARM facilitation of curriculum content and methods.

The more a school faculty tries to be aware of, arranges curriculum around; and, “dances with” children’s’ Sensitive Periods, the more you have a Team Human school.

We know more about Sensitive Periods. Many are crowded into birth and the first three years. This has to do with the brain’s “pruning” of “unused” — ”unstimulated” is likely more accurate — neural capacity. Later in childhood, the spacing of Sensitive Periods are more drawn out.

Sensitive Periods continue significantly beyond puberty; yet, less prominently, too subtle to be obvious to most people, except astrologers. What takes over? Personal choice becomes far more significant.

An expanding spiral of behaviors

Have you ever watched squirrel behaviors in a park? As cute as squirrels are, after a while you notice how limited their behaviors are. Their repertoire of behaviors is circumscribed to a small range of behaviors they repeat, repeat, repeat. This is one reason they make very poor pets. They can’t learn your fingers, which smell good, are not food for them to chew on to larn if they are edible.

The Habit Body

Many readers will likely be interested in Your Habit Body; An Owner’s Manual: Gut-brain Axis 2.0 (2nd ed). Briefly, all learned behavior is learned thru repetition. Our habits are memories of behavior, conditioned to repeat. In adults, 95% of our psyche is well-described as habits on five levels: physical-metabolic, imaginal, emotional, mental and mythological. What balances this 95% of our psyche is 5% of free choice. Our conscious waking Self has the roles and tasks of Habit Editor, Habit Manager, New Habit Initiator; and, Habit Deleter.

When we are born, we have had time to learn few habits. Gradually over 18 years, our range of “composted” learned behaviors expands, extends, deepens. We can say, to introduce the right new behaviors, with the right children, at the right time, is the goal of Sensitive Periods wisdom.

In developmental psychology and developmental biology, a sensitive period is a maturational stage in an organism, during which the etheric body (the pre-nervous system) is especially sensitive and receptive to certain environmental stimuli and input — Adapted from

Starting in-utero, children pass through developmental phases-stages where a predisposition or sensitivity to learning comes to the fore.

“Skills” are a fictitious abstraction

“Skills” has utility for teens and adults in vocational education and designing competency evaluations. “Skills” are an intellectual observation and summation of specific observed behavior. In this, “skills” is a strictly one-sided, left-brain-only, label for a set of behaviors.

What’s happening in the brain? Neural pathways in the 3D hologram of our brain either are sufficiently — or insufficiently — myelinated thru repeated practice. This is how memory and habits form.

For children prior to puberty, “skills” has no reality. What is real is adequate and sufficient practice of healthy habits. This is what children prior to puberty want to do.

For individual children unable to form a habit pattern after the rest of the class has mastered the habit, we do Child Study to explore possible unconscious blocks and obstacles and remedial strategies.

Steiner’s word “capacity” is better than “skill” for children before puberty. “Habit” is even more clear than “capacity.”

What do we observe in healthy infants and children? They appear ready, willing, able and wanting to form new habits. Why? They intuit they are “blank slates” upon which repeated experiences and stimuli will be written. Infants smile, reach out, imitate sounds and so on.

More esoterically, the very young child has an empty, unconditioned etheric body. It’s “hungry” for input and stimulation.

How long does a Sensitive Period last?

This varies. This graph is useful:

dg-sensitive period

Learning a language is our best example here. Research of decades ago confirmed a peak period of receptivity to learning language exists in the first few years of human life. Once this blossom fades, learning a language, takes more time, effort and attention. Why? The task has to be done cognitively. During the Sensitive Period language can be learned and “installed” simply by repeated imitation. Sensitive periods are periods of readiness for forming a new set of habits.

Q: Would you go so far as to suggest the very young child’s “hunger” for certain stimulation at certain times is similar to a female cat in heat?

A: This is closer to the truth than most people want to imagine. Children do indeed long for certain instruction, at certain critical time periods; yet, are inarticulate about their needs. Like a cat in heat, their longing for instruction exists primarily in unconscious firmware, the sequence of Sensitive Periods.

Yes, the very young child is as hungry as a female cat in heat for certain stimuli. Yet, the young child, especially after two years of age, begins to have more choice and awareness of socially appropriate behavior. A female cat in heat has only hard-wired instinct driving her relentlessly, she is a slave to her instincts, this is less so in humans. Our mandate is to develop and master free choice.

Q: What’s the difference between a child repeating certain actions over and over again and Sensitive Periods?

A: “Perseveration” is the word for “repeating certain actions over and over again.” This has more to do with the unconscious trying to myelinate neural pathway in our hologram of our neurons. In autistic kids, sometimes they cannot myelinate the pathway, and so, may perseverate for years.

A less severe form of this is sometimes called OCD, if not due to trauma.

Healthy Sensitive Periods in neuro-typical children are neither of these. SPs appear in young children as willingness to do an activity over and over again until some level of self-mastery is satisfied. SPs can also appear as inarticulate longing for certain instruction and parental behaviors.

Michael Jordan and Tiger Woods were not only compelled to practice their sport at four years old; they were willing to practice their sport. Over time, out of repetition, their habit repertoire and awareness of behaviors in their sport became expanded, become more nuanced and more masterful.

Q: My young child likes to hear and sing the same song over and over again. Why is this?

A: Repetition is essential for habit formation. Organically, when the same thing is done repeatedly, the same certain set of neurons, in a pathway, are reinforced with lecithin This is called myelination. Clearly the young child is practicing, rehearsing, ordering, habiting, something internally, according to their preferences.

No need to over-think this. It could be joy of learning. It could be practice of auditory processing. It could be a break from more taxing, more tiring hand-eye coordination practice. It could be one of few ways the young child has to express her joy in song. It could be healthy liver or spleen expression. What if it’s a combination of these factors?

Unless the young child has already self-identified with singing as an activity and possible future career, we err calling this “skill development.”

… In Casa de Bambini, Montessori observed the [sequencing of] sensitive periods was not strictly linear. They do not follow each other. Some run parallel and some overlap. It was obvious to her, sensitive periods the child passed through, were not only an aid to the development of his physical body development. They were also an important aspect of his learning process. …

Maria Montessori and her ‘Sensitive Periods’ — https://Montessori/blogs/news/17958864-maria-montessori-and-her-sensitive-periods

Not “Critical Periods”

In animal psychology, in 1935, Konrad Lorenz described learning behavior in young ducklings and goslings (ducks and geese). See article in To Learn More at end of this Chapter.

Many male-thinking science researchers restrict “critical periods” to “hard-wired” instinct, as in ducklings who imprint to a mother duck. They ignore — or at least can’t prove — human Sensitive Periods are less rigid, more fluid-flexible; yet, still time-limited.

The problem? Critical periods can be studied objectively-academically without empathy: call them “skills” and be done with it.

In contrast, study of, and “dancing with,” Sensitive Periods in human children, absolutely requires empathy and the values of iNtuitive Feelers (terms from MBTI since Kiersey-Bates in the 1970s).

The superpower of iNtuitive Feelers is “empathy.” With it, they are able to take another’s Sensitive Periods seriously. This suggests why since 1970 all of K-12 education is shifting away from Thinking-only and towards a BALANCE between rational Thinking and rational Feeling.

Team Machine factory-style schools are characterized by little or no interest in a child’s journey, thru the Sensitive Periods. “Teach to the textbook: is their mantra.

If we wish a future more organized around Caring Economy jobs and Commons Stewardship jobs (first) and technology (second), K-12 schools teaching a balance of healthy empathy alongside STEM are needed.

Waldorf-methods whole-child schools, informed by Team Human, are our hope for growing sustainable children; and, K-12 schools worthy of our affection.

Multiple versions of Sensitive Periods

Believe it or not, each of the following has a different conception of Sensitive Periods:

- Montessori

- Waldorf

- Attachment theory, John Bowlby, Mary Ainsworth

- Arnold Gesell

- Pam Levin Seasons of Change

- Gail Sheehy Passages (1974)

Any additional variations?

Of all of these I find Waldorf’s scheme of Sensitive Periods simpler; therefore, easier to perceive and administrate.

While the earliest explorers of “sensitive periods” in children were probably Froebel and Steiner, the exact phrase comes from Maria Montessori. The earliest incidence I find is 1966:

The child has a creative aptitude, a potential energy enabling it to build up a mental world from the world about it. He makes numerous acquisitions during the sensitive periods, which put him in relation to the other [probably “outer”] world in an exceptionally intense manner ~ From The Secret of Childhood (1966) by Dr. Maria Montessori.

“Sensitive period” appears 25 times in this book. However by 1966, Montessori and Waldorf were competing for the same market of private school parents. How her phrase simply improves on a basic Waldorf idea is worth considering.

A complete exposition of all point of view on Sensitive Periods is not needed here. What is needed is comparison between the two groups of Sensitive Period models:

- Classic Waldorf model of seven year cycles, with no leapfrogging of “parallel” periods,

- Montessori, modern Gesell, Pam Levin models, without any seven year cycle but with much smaller “leapfrogging” periods of parallel development.

For only the above, some baseline of understanding will be useful.

Child capacities by grade level, a list

Grade. K — Moods of magic and rhythm. When the sprouted plant is seeking the sun, there is little need for adult conversation from the neck-up. Let’s awaken children’s senses to healthy perceptions, to perceptions of a healthy, safe world. Let’s gently awaken enthusiasm and love for worthy adult teachers. For ‘old’ five year old boys and children in their third year of K, make sure sufficiently dynamic activities are available.

Gr. 1 — Mood of quiet priestly group rituals. Ear training: lyre, tone blocks and blindfold games (see Else Gottgens PDF on blindfold games online). Auditory discrimination of tones: What do you hear? Phonics competency: rhyming and alliteration (‘beginning rhyme’).

Remedial work for all: body geography, crossing the midline, drawing with feet. Active Arithmetic (AWSNA 1995), using kids as counters before ‘heap counting.’ Child Study teacher meetings about children not keeping up.

William Glasser’s Quality Discussions of posted teacher and student work: What do you see? What do you appreciate? What makes it beautiful? Yet nothing too cognitive nor critical. Focus on appreciating what is beautiful, how and why it’s beautiful. Inspire by example and demonstration, inspire students to imitate. This is how they improve their performance.

Gr. 2 — Start of DAILY mental math, through eighth grade, in the mood of game, with adequate and sufficient variety.

Grade 1–3: Mood of self-control, priestly performance of heartfelt rituals.

Gr. 4 — Wean them off copying stories from the board to composing their own stories, with guidance. See Arthur Pittis’ article in Fall/winter 1995 “Renewal.”

Gr. 4–8 Glasser Quality Discussions of student work: What makes this piece successful? Now we explore our faculty of discernment — and speaking kind words about other’s efforts.

Adequate and sufficient academic rigor. Those dads will yank their kids if they don’t see progress in math-reading comparable to what is happening in corresponding public school grades. Child Study teacher meetings are needed about children not keeping up. Investment in remediation is needed.

A sensitive period for verbal imitation of spoken language DOES NOT EQUATE with a sensitive period for learning to read

The insight of Sensitive Periods can be distorted to sell SuperBaby commercial products and even whole philosophies of education. In 2018 Mr. Google had 1.3 million pages for: superbaby

The top-rated result is a book: SuperBaby: 12 Ways to Give Your Child a Head Start in the First 3 Years: “At the age of 3, children enter sensitive periods related to reading and writing.”

Human children have a sensitive period for imitating spoken language (“language acquisition”). This is entirely distinct and separate from apitude for reading printed words.

Equating learning spoken language with reading printed words is first-order Super-Baby nonsense. As any attentive parent learns, if an an infant loves you, they love to imitate you — including making the sounds you do and making the connections between words and meanings you authorize. They are imitating you, NOT expressing an interest in learning to read.

To Learn More

Sensitive Periods in Attachment theory

… many researchers claim the first six months of life are crucial for emotional and social development; and, for the development of healthy attachment (bonding).

Children who do not receive or accept warm nurturance during this time period, have greater emotional difficulties; such as, being fearful, distressed and avoiding contact with other people.

If emotional neglect [or refusal of care] continues, infants may find it difficult to form stable relationships later in life.

[Originally more of a “critical period” concept, attachment theory] was later modified in favor of a “sensitive period.”

The first six months remain ideal for experiencing healthy attachment. However researchers say children can recover from the absence of healthy attachment even beyond the first six months, if they are given a loving and nurturing environment which they do accept and receive into themselves.

Researchers found children in orphanages adopted before the age of one year, were better emotionally adjusted, than those adopted later. However, if warm nurturance was given to children adopted even later than a year, early deprivation can be compensated for to a large extent.

… This discussion helps us reflect on the degree to which early childhood experiences mould individuals. It also sheds light on possible pathways of development in the face of early deprivation and neglect.

Excerpted and revised for clarity from Critical and Sensitive periods in Child Development By Priyanka Padhy (2013) —

SuperBaby can compensate for developmental delays

While the above seems exactly right to me for under-privileged (under-stimulated) children, to remediate developmental delays, I see no convincing evidence accelerating the sequence of Sensitive Periods for Language Arts benefits neuro-typical children.

In fact, I saw the opposite. In the period 1975–1990, if you were a parent and your child did not fit into public school, Waldorf schools were often the “school of last resort” for parents, where children with atypical habits could get much more specialized, usually but not always, more effective remedial attention.

In my experience, this worked more often than not. Still, it was also stressful on schools and teachers involved.

The two most common categories of cases I saw were like this. The child is usually four years old. He or she has already been conditioned to read and often do arithmetic as well. Sometimes this comes with the adultified Little Professor affect, sometimes not (worse if it does). When we got these children at schools I was connected with or visiting, we understood the need for — and the difficulty of — re-orienting them OUT of Adult Nation and back into the Land of Childhood stages, appropriate to their age.

What often worked best here was removing parental and teacher anxiety about student performance. Provide the child with uninterrupted experience of safety and protection. In adult speak we might say, “safe to be yourself” and “safe to act your age.” To heal, these children have to UN-learn lessons they learned prematurely, lessons we hope they do embrace — after puberty.

What works best here — which Waldorf schools were often not optimal at providing — was social-emotional learning not about other children but towards self-empathy. They can’t take it in cognitively much. If adults model it they can learn it.

Improving a healthy social life for these children, gives them the best chance of re-norming to their age group. Then the child comes to school for their friends, not because school subjects are engaging. If successful, after a couple years, puberty does catch up to them.

Q: Aren’t your two examples above the same child at two different ages?

A: As a pattern, yes. Healing is still the tone of discussion. This is only thing that really works. If you take them to a psychologist, they get diagnosed but they get no or too little empathy and re-integration into the organic quality of their own childhood. The Little Professor has been removed from childhood. Can you put Humpty Dumpty back together again?

The second most common category of disturbed child I saw was usually a third grader who is already burned out on school — they have had it. They learned to read early, they did math when they were two, at nine years old they have already read all the Narnia books. They feel like there is nothing left for them. ‘What am I supposed to do? just sit around and wait for puberty and adulthood to catch up with me?’ This too is sad to see.

What works best here was social-emotional learning:

- About other children, “When you talk like a teenager around your classmates, they judge themselves as failures and draw away from you. Is this your intention?

- Towards self-empathy, When you said that unkind remark (about yourself or another child) were you feeling hurts? Distressed? Lonely? Oh, you were feeling lonely! I get it. You wanted friends, companions. Well, what else could you have done to meet your need?” Improving the child’s EQ and walking them thru explicit interpersonal competencies, gives them a good chance of re-norming to their age group. Then they come to school for them friends, not because school itself is engaging. If successful, after a couple years, puberty does catch up to them.

I saw first-hand both old and new Waldorf schools struggle to provide such social-emotional learning (SEL). In 1919 concepts and language for SEL was weak to non-existent. Hiring an outside consultant, often an experienced, successful Kindergarten teacher, was often tried and can work.

Even in 2018 I’d like to have even one school to point to with consistent success in conveying -imparting SEL to children. I hope they exist. Consequently, SEL results in schools is often clumsiness with SEL problems. Is it still too early for these schools? The methods, training and curriculum either don’t exist yet; or, investment in staff trained in these methods is still too weak. If you know exceptions please email or call me. I want to learn what’s working.

Paradoxically, the USA is the birthplace of most explicit social-emotional learning and curriculum.

Q: Aren’t your two examples above the same child at two different ages?

A: If you heal the Adultified Child when they are four, and they stay in a Waldorf or Team Human school, you do not have to it again at age 9–10. Notice the theme in both is individualized healing in the area of SEL.

Explicit SEL training is only thing I’ve seen which really works with kids thru middle school. If you take them to a psychologist, the child gets diagnosed; yet, they get no or too little empathy and re-integration into the organic quality of the Land of Childhood. The Little Professor has been removed from childhood. Can you put Humpty Dumpty back together again? It takes a village.

In the 1980s-1990s David Elkind spoke frequently at Classic Waldorf schools. His books, Miseducation (1987), The Hurried Child (1993), The Power of Play (2007?) informed early childhood education professionals of the potential dangers of:

- SuperBaby ambitions in parents,

- Pushing down, also dumbing down, topics like biology for consumption by kindergarteners.

Other versions of Sensitive Periods

Acknowledging and cooperating with Sensitive Periods is the biggest Unconscious Pattern in successful K-12 education I can find. Wherever you first encounter this is likely to make a deep impression. It’s important to avoid the Holy Man’s disease, imagining only Montessori or only Classic Waldorf enjoys this wisdom.

In the next 100 years of K-12, awareness of this wisdom and its corollary will increase. Lip service only paid to Sensitive Periods is what I saw in factory-style schools. If parents wish to know how Team Human your school is, please arrange to get a close-up view of WHERE and HOW your school employs this wisdom.

Why? The Devil is in the details.

Superbaby in Asia

The insight “sensitive periods” benefits from being discussed in an NF (empathetic) framework-context. This insight has even made its way into Chinese K-12 education literature:

What are the secrets hidden behind the behaviors not understood by parents? Opening the book, you can walk into the inner world of children and understand all sorts of seemingly inexplicable behavior motivations and be familiar with one problem you have never realized or ignored — sensitive period. After you read the book page by page, you can use the golden key in the book to crack the secrets of children in the sensitive period and accompany them to spend the sensitive period successfully. In this way, your child can grow up to be confident, caring and outstanding and have a sense of security and creativity. — Walk Through the Sensitive Period from Age 3 to 6 with Your Kids (Chinese Edition) (Chinese) Paperback — February 1, 2017 —

Perhaps every new generation has to go thru the SuperBaby dream.

NEXT ~ Chapter 5 — K-12 education as a 3D hologram viewable from multiple angles



Bruce Dickson

Health Intuitive, author in Los Angeles, CA