Surprisingly, our inability to remember events from our first two or three years of life clarifies the basis for durable learning of anything.

The following is an approximate transcript of the podcast on childhood amnesia.

We’ve talked previously on this podcast about Beginner’s Mind and the way the very young child’s mind is optimally tuned for learning. The mastery of language by children between the ages of 2 and 4 is an incredible accomplishment. There is, however, one way in which this stage of Beginner’s Mind is not worthy of emulation and that is in its relative inability to generate long-term memories. Most psychologists maintain that the earliest memory for most children is between their 3rd and 4th year of life. There are continuing losses of these early memories until about 7 yrs. old when long-term memory of what’s left seems to stabilize. This well-known phenomenon called childhood amnesia can shed some light on how adult minds learn best. Join me today as we explore how we can produce durable learning—learning that lasts.

The memories recalled by small children are called episodic memories—memories of events that they experienced. Episodic memories are a subset of a larger category of memories that psychologists call declarative memories. Declarative memories can be declared—that is they can be verbalized. In addition to episodic memories, the declarative category includes semantic memories. Semantic memories are what education is designed to produce: knowledge of concepts and the way they connect to other concepts to answer important questions. It appears that semantic memories are stored differently in the brain from episodic memories. Episodic memories, however, are much easier for psychologists to study and they may give us some insight into semantic memories.

The earliest memories of childhood episodes are most often coupled with strong emotion—from the child’s perspective at least. The emotions may be positive or negative. One of my early memories was of my mother sending me to kindergarten with a broken handle on my lunchbox. I was very distressed with being expected to manage an unwieldy metal box with a breakable glass-lined thermos bottle inside. Trivial as it turned out, but not to me at 4!

One attractive explanation for the failure of young children to remember most of their early childhood is that their brains are insufficiently developed to remember much long-term. That turns out to be a gross oversimplification.

Children at the age of three have a demonstrated ability to remember events that happened when they were two. 4-year-olds may recall some of these same two-year-old events but forget others that they remembered when they were three. Memory of these early events continues to deteriorate throughout early childhood so that most early events are no longer recalled by the time the child is seven. What this tells us is the very young children do have the necessary brain structures to construct episodic memories that last for months or years, but something accompanying brain maturation erodes all but a handful of these early memories. While children are losing early episodic memories, they are improving in their ability to formulate and build enduring conceptual frameworks—semantic memory.

There are various theories about what causes childhood amnesia. This podcast is not meant to be an exhaustive and definitive discussion of the phenomenon. I do have links that go into more detail in my blog post that accompanies this podcast. You can find links to papers and videos by some of the experts in the field at deepanddurable.com.

The structures of the brain that are known to collaborate to produce long-term memory are the amygdala, the hippocampus, and the pre-frontal cortex. All of these undergo significant development during early childhood and the early elementary grades. Along with this development, verbal abilities improve, and the child can express their ideas with increasing clarity. Memories from the first few years of life are preverbal. The child at the time of the event didn’t have the vocabulary needed to encode the event in the form of named concepts even if they did understand what was going on. Necessarily then, memories of early episodes involve sensory impressions more than a narrative of what happened.

When my young grandchildren occasionally burst into tears with frustration, my wife and I frequently say, “use your words,” “tell us what happened.” This is sometimes successful with three-year-olds, but often successful with four-year-olds. Being preverbal isn’t just a language problem. It is a conceptual problem. Noam Chomsky’s thesis that our brains are wired for language has been accepted by most linguists and neuroscientists. I submit that language is the currency of ideas. Language gives voice to concepts. Most fundamentally our minds are wired to seek patterns. Patterns are regularities and these regularities are concepts. To work with concepts in our own minds and to communicate them to others requires labels and those labels are fundamental to language.

Two-year-olds have very simple conceptual frameworks that closely correspond to their limited vocabulary. Their concepts are mostly nouns. They are physical things. Actions and chains of causation are largely mysterious unknowns to children this young. Emotions are experienced and elicit smiles or crying from the youngster but are not yet formulated into concepts. Concepts are the basic elements of thought. Experience from encounters must be encoded into concepts if they are to be remembered accurately. The brain transacts its business using concepts. Preverbal and nonverbal memories are not encoded into concepts identified with language labels. As a consequence, such memories are eventually purged.

If you listened to this podcast last season you encountered the idea of consolidation. This was the last of the 7 C’s of Cognition. Consolidation happens primarily as we adults sleep. Most of what our brains paid attention to during the day is flushed away during consolidation. Only what is useful to the brain survives this nightly purging. This generally means concepts and their connections which help to answer questions or solve problems we care about. This is why so much factual information is lost. Variously called dead facts or inert information these items fail to justify their existence over the long haul and they are purged.

There is evidence that something similar, but much more extensive happens in the years from 0-7 and to a lesser extent, during puberty and adolescence. In both periods of life there is a proliferation of neurons in specific brain regions (such as in the hippocampus associated with memory in 3-7-year-olds). These neurons disrupt existing neuronal structures and neurons are selectively pruned over time. Pruning may involve removal of certain synapses (where neurons communicate with each other) or it may involve selective removal of neurons due to apoptosis (programmed cell death). Pruning is designed to increase efficiency. In the young child this looks like an overall improvement in encoding of concepts and long-term memory. In adolescents this pruning results in an improvement in executive functions which can improve self-control and result in better decision-making.

A memory trace in the brain is termed an engram and was so named in 1904. One authoritative source defines it this way, “An engram . . . is formed by a group of neurons that (1) become activated by a specific learning experience, (2) are modified by this experience, and (3) are reactivated by re-exposure to the same experience, inducing a change in the behavior of the animal.” This definition appears in a 2021 review in the Journal of Biological Chemistry and it also summarized our knowledge of engrams this way: “questions surrounding the molecular and cellular mechanisms of how information is encoded, stored, and recalled remain largely unanswered.” We know we construct concepts as we recognize patterns in objects and events. We know we can have long-term memory of those ideas and can apply those we understand to solving problems. How the brain pulls off these marvels is NOT understood. Neuroscientists describe events surrounding the construction of a brain engram in more detail and with longer chains of causation every year. Description and correlation are not causation and explanation, however. Can the brain understand the brain? I think not. The human brain is a testament to the inscrutable wisdom of its Creator.

Childhood amnesia gives us a glimpse of the importance of concepts to understanding and memory. Enduring memory can only be built on a logical foundation of concepts. Children without an adequate conceptual framework cannot long remember most events they experienced. Take as an illustration a two-year-old child in Indonesia who does not have the concept of an earthquake. (Earthquakes are frequent in Indonesia). They may experience an earthquake with their family as an emotional event. They may remember adults being confused and perhaps structural damage to their home. As a three-year-old they may not remember the event. It is even less likely when they are four. The caveat is that the parents may remind the child of the event later in life when they are able to understand the concept of an earthquake and that can modify, justify, and explain the child’s early sensory impressions. Coupled with photographs this kind of repeatedly rehearsed family memory may convince the child that they personally remember the event.

Semantic learning especially is premised on the development of robust conceptual frameworks. Deep and durable learning is the result of constant remodeling of your conceptual networks. You create new conceptual categories through exploration, and you work to create a logical home for them within your existing network. You find new ways to link old concepts to those new concepts. But you also prune your frameworks. Pruning occurs to root out contradiction or explanatory failure. You can prune a connection, but you can also prune a concept—remove it as illegitimate.

Faulty conceptualization occurs when one’s personal concepts include items or actions that should not have been bundled together. The individual has a misconception and may come to all sorts of unjustified conclusions as a result. Classic studies of misconceptions in science were captured in two Annenberg video series. In Private Universe Harvard graduates chosen at random including some who had taken physics at Harvard showed they retained early elementary school distortions of how the seasons on earth are produced as well as a flawed understanding of what causes the phases of the moon. The title, Private Universe, is intended to communicate that the flawed physics of these individuals made sense to them even if their misconceptions failed to pass scientific muster in the real world. Indeed, misconceptions are very difficult to unseat. Unlearning feels traumatic because we are compelled to release our cherished, but wrong, ideas.

 In the second Annenberg video series, Minds of Our Own, there is an episode called “Lessons from Thin Air.” In it randomly selected Harvard graduates showed profound misunderstanding about how trees grow. The organic material in a tree comes from carbon dioxide in the air through a process that is powered by sunlight.  We call this photosynthesis. Many Harvard graduates maintained that the mass of the tree was created primarily from materials extracted from the soil by the roots.

It is as though the concept of photosynthesis did not exist to these adults. To be fair, some shriveled version of photosynthesis was probably improperly assigned to a different silo in their brains. Think of what it would mean if you didn’t really have a concept of photosynthesis. There would be gaping holes in your understanding of the biological world, but you probably wouldn’t see them. You would attempt improbable explanations to account for what photosynthesis actually does. Cognitive failures can be due to actual concept blindness. Failure to see a pattern and construct the relevant concept leaves an individual groping and confused when faced with questions the missing concept would answer.

As I bring this episode to a close, I hope you are beginning to see that nothing less than an intentional focus on concepts and their connections can produce deep and durable learning. Conceptual sparseness in early childhood is at the root of our inability to create and retain memories of our early years. Misconceptions and concept blindness in adults explain some of the incredulity and inability to listen to and respectfully engage with the views of those with whom we disagree. Reflect on today’s tribal pattern-making minds gone berserk in creating elaborate preposterous conspiracies which are communicated with arrogant ignorance.

Philippians 4:5 (KJV) commands us that we are to let our moderation be known to all [because] the Lord is at hand. Moderation is an endangered species. Perhaps we have lost the concept itself. Is this an example of concept blindness? What is moderation? Moderation can also be translated as gentleness or graciousness. Ouch! That’s what God expects in our conversations.

If you are interested in exploring the phenomenon of childhood amnesia further, I suggest that you sample the lifetime output of one the most thorough researchers of the phenomenon, Carole Peterson of Memorial University of Newfoundland.

Here are some links to her work:

A 2021 review that challenges the 3-4 year limit for earliest memory.

A fascinating video summarizing her work.

A bibliography of her papers on childhood amnesia.