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The Spongey Brain: Why Children are So Good at Learning

Published on Psychology Today

My son Charlie just turned 3. By this time, we would have liked to put Charlie in preschool, at least part-time, so that he could play with other kids his age and maybe even start learning some numbers and letters. Unfortunately, the COVID-19 pandemic got in the way of those plans, and we’re finding ourselves in a position where Charlie has spent over 1/3 of his life at least partially quarantined at home. But despite the fact that he’s never really seen the inside of a classroom, Charlie is an incredible learner. I thought he needed to be in preschool to learn letters and numbers, but somehow he’s already learned them on his own. In fact, he doesn’t just know the names of the letters, but he also knows the sounds they all make, and he’s even stringing together a few of them to read short words. How on earth did he learn all of this? Charlie does have an older brother who’s learning these things in remote kindergarten, and Charlie plays with several spelling apps on a tablet a few days a week, which could have done the trick. But he’s had no formal schooling. Even as an expert in child development, I’m beside myself: What makes him such a good learner?

You might have heard the phrase “Children are sponges” to describe the propensity for learning that children seem to have. They pick up new words and phrases all the time (even the ones you don’t want them to), and even learn to apply them in appropriate situations. Before he even turned 3, Charlie could look at me during a particularly stressful moment and ask, “Mommy, are you frustrated?” I mean, it sounded more like “fwua-stu-ated,” but you get the idea. And Charlie isn’t unique: Between the ages of 1 and 2, children can learn between 8 and 10 new words a day. Can you imagine having to do that as an adult?

Although you don’t have to be a neuroscientist to notice that children are amazing learners, actual neuroscientists have confirmed what we have always suspected. Infants’ are born with brains that have an overabundance of what we call synapses, or connections between neurons, which are the most fundamental parts of our brains. These connections make it so that infants’ brains are incredibly flexible to adapt and change based on what they experience in the world and the specific challenges they face. This flexibility is what researchers refer to as plasticity. It’s no coincidence that the word plasticity has “plastic” in it, reminding us of substances that can bend and flex when you need them to.

Because of this plasticity, infants have a propensity to learn that we just don’t have as adults. For example, infants are born with the ability to distinguish between the sounds from any language in the world. Researchers discovered this by presenting 7-month-old infants with sets of English sounds and Hindi sounds that are not part of the English language. They found that 7-month-old infants were easily able to discriminate between both English and Hindi speech sounds, while native English-speaking adults couldn’t even hear the difference between many of the Hindi sounds (Werker, Gilbert, Humphrey, & Tees, 1981).

The same is true for the ability to distinguish between all different kinds of faces—regardless of species. For example, if you were to show a 6-month-old and an adult two photographs of faces and asked them to decide whether the photographs were of the same person or of two different people, both the 6-month-old infants and the adult would be equally good at the task. But, if you show the 6-month-old infants and adults pairs of faces of other animals (e.g., chimpanzees), only the 6-month-old infants would get more than half of them right (Pascalis, de Haan, & Nelson, 2002).

This phenomenon is called perceptual narrowing. It refers to the fact that when we are born, our brains are flexible enough to distinguish between a variety of faces, and between the sounds in a variety of languages; but as we gain more experience with the faces we see most often and our own native language, we become experts at those particular faces and that particular language, and we lose the ability to distinguish between the things we don’t often encounter. In terms of what’s happening in the brain, as infants gain more experience with the world, that abundance of synapses that they’re born with gets pruned down, leaving only the ones they use. This has been called the “use it or lose it” phenomenon, and it is part of why our brains start out like sponges, but then become more efficient at processing the most important information over time. For some areas of learning, this happens quickly, and by the time infants are around 9 months of age, their ability to distinguish between all different kinds of speech sounds and faces declines and starts to look more like adults’.

For other areas of learning, there’s more time to soak up the important information. For example, because of children’s amazing propensity for learning language, many scientists believe that there is a special window of time—known as a critical or sensitive period—where a child’s brain is especially receptive to learning language-related information. Research supports this. In one classic study, researchers looked at immigrants who came to the United States sometime between the ages of 3 and 39. After giving them a variety of language fluency tests, the researchers found that performance on the tests was not related to how many years the immigrants had been in the United States. Instead, what mattered for English fluency was when they had first come to the US: The younger they were, the better they performed. Gains in performance increased until about puberty, but after that age, it didn’t seem to matter when the adults came to the US or how many years of experience they had with English—they performed poorly across the board—suggesting that learning a language during those critical early childhood years is important for mastery (Johnson & Newport, 1989).

So far, this all sounds great for kids, but terrible if you’re an adult. But don’t worry—there’s a lot that adults are better at too, and although there’s less room for flexibility as we get older, our brains are still quite adaptable, especially when we most need them to be. For example, adult women’s brains undergo important changes before and after pregnancy to help prepare them for motherhood (Kim, Strathearn, & Swain, 2016). For example, a group of researchers collected brain scans from mothers before and after they gave birth and found that the structure of mothers’ brains—specifically the areas that were active when the mothers were looking at pictures of their own babies—did in fact undergo significant change for at least two years after the women gave birth. The researchers think that these changes might help women to be more empathetic, and extra attentive to the emotional needs of their newborns (Hoekzema et al., 2017).

The moral of the story here is that children (and sometimes, adults) are such amazing learners because their brains are designed to absorb information. There is a slight downside to this—namely, that since children are always learning, they might learn things you don’t want them to, like how to drop a curse word in public if you’re not careful about what you say (and I speak from experience here). But the major upside is that even if your kids have been locked up in the house for a while, there is still a lot that they can learn. After all, while Charlie might be bright, he’s not a genius—he’s just a sponge—and even though he isn’t in a formal classroom yet, he’s still soaking up quite a bit.

Photo by nickelbabe/pixabay


Hoekzema, E., Barba-Müller, E., Pozzobon, C., Picado, M., Lucco, F., García-García, D., ... & Vilarroya, O. (2017). Pregnancy leads to long-lasting changes in human brain structure. Nature neuroscience, 20(2), 287-296.

Johnson, J. S., & Newport, E. L. (1989). Critical period effects in second language learning: The influence of maturational state on the acquisition of English as a second language. Cognitive psychology, 21(1), 60-99.

Kim, P., Strathearn, L., & Swain, J. E. (2016). The maternal brain and its plasticity in humans. Hormones and behavior, 77, 113-123.

Pascalis, O., De Haan, M., & Nelson, C. A. (2002). Is face processing species-specific during the first year of life?. Science, 296(5571), 1321-1323.

Werker, J. F., Gilbert, J. H., Humphrey, K., & Tees, R. C. (1981). Developmental aspects of cross-language speech perception. Child development, 349-355.


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