A Child's Intelligence Begins with Japanese Language Ability.

When we look at young children's language development, it is easy to focus on speech. If a child talks a lot, we tend to feel that their language is developing quickly. If they do not talk much, we may assume they are behind.

But language ability includes the perceptual side of understanding what is heard, the thinking side of working with that information in the mind, and the speech that appears outwardly. Some children are quiet even though they have strong comprehension, rich vocabulary, and deep thinking. Others can read textbooks and talk a great deal, yet their ideas may lack clarity or structure. Reading and speaking alone do not tell us enough to judge a child's comprehension or thinking ability.

When we look at a child's language, we need to pay attention not only to whether they can read things like kanji or how much they talk, but also to what they understand and how finely they are able to perceive the world. Language ability is far larger than the amount of words that come out of a child's mouth.

Vocabulary plays a major role in language ability. Words are not merely strings of sounds or letters. They are connected to the concepts we use to recognize the world.

If a child knows only a few concepts, something may be right in front of them and still not be extracted as meaningful information. On the other hand, as vocabulary and knowledge grow richer, children can perceive finer differences and relationships even when looking at the exact same thing.

This can be compared to a computer operating system. Children first acquire language as a basic system, and then continue enriching it with more vocabulary and concepts. As they do, the "resolution" with which they perceive the world becomes higher. Richer language is not simply a matter of knowing more words. It also means being able to draw richer information from the world.

Knowing words alone does not necessarily mean a child can understand a text. The words they read or hear need to come together in the mind as meaning not just at the level of individual words, but at the level of sentences and full passages.

The foundation of Japanese language ability is vocabulary and comprehension. Rich vocabulary expands the range of what a child can understand, and as their understanding grows, it becomes easier for them to acquire still more new words and concepts. Through this cycle, language ability becomes richer and richer.

Once children can understand the meaning of a single sentence, the next ability they need is understanding the relationships between sentences and between concepts.

With “however,” what comes before and after is contrasted. With “therefore,” there is a cause before it and a result after it. In “if you do this, this happens,” there is a conditional relationship. Logic is what allows children to work with these relationships between pieces of information.

Vocabulary helps children perceive concepts, comprehension helps them grasp the meaning of sentences, and logic helps them think about the relationships among multiple pieces of information. To build Japanese language ability from early childhood, two essential pillars are enriching vocabulary and nurturing the ability to think about relationships between pieces of information. Picture books and stories, conversations between parent and child, and a wide range of experiences all become input for that growth.

Math, science, and social studies each deal with different kinds of knowledge. But in most cases, the tool children use to learn that knowledge is language.

In social studies, children read text and understand the meaning of events and systems. In science, they read explanations of phenomena and organize cause-and-effect relationships. Even in arithmetic and mathematics, they need to understand the conditions presented in words and translate those relationships into equations.

In other words, to acquire knowledge in any subject, children need the language ability to understand the explanations being given. That is why Japanese language ability does not remain limited to one subject alone. The ability to receive information through the mother tongue, understand its meaning, and think about relationships continues to be used across all other school subjects as well.

Children acquire their mother tongue in everyday life. They talk with family, play with friends, and gradually become able to express their needs and feelings.

As they grow, they begin handling ideas that go beyond the concrete situations right in front of them. To read textbooks, understand abstract concepts, explain reasons, and hold discussions, children need a level of language ability that is more advanced than everyday conversation.

The framework that describes this difference is BICS and CALP. BICS refers to the everyday language used in ordinary interactions with family and friends, while CALP refers to the academic language used to understand textbooks and to think and discuss abstract content. It is important to help the Japanese skills children acquire in early childhood grow, as they mature, into CALP-level Japanese language ability. To do that, they need richer vocabulary along with stronger comprehension and logic.

When children can understand a passage, they can organize the information in it as meaning and relationships. Because they can see structures such as cause and effect, similarities and differences, and whole and part, they no longer need to memorize everything one piece at a time. In other words, the cognitive load becomes lighter.

On the other hand, if learning continues without sufficient understanding of meaning, memory becomes the final fallback. Children memorize formulas without understanding how the formulas work. They memorize answers without understanding the meaning of the text. Even if they can read aloud, the sentences pass by as sound alone, never becoming meaning.

Part of the achievement gap that cannot be explained by study time alone comes from this difference. Before children try to memorize information, they need to be able to understand its meaning. They need to be able to organize information through language. That ability changes the quality of learning.

When children speak Japanese, they are not consciously thinking about grammar in everyday life. Even so, as they grow, they become able to use particles and inflections with remarkable accuracy.

Once they reach school age, they begin using Japanese to think about Japanese itself. They step back and examine the language they use every day from one level above: “What does this word mean?” “What is this sentence expressing?” “Is this expression correct?”

When language is used to explain or analyze the meaning and grammar of language itself, the language used for that explanation is called metalanguage. The language children use to understand and organize subject content such as “What is the shogunate?” or “How is addition different from multiplication?” is Japanese language ability functioning as metalanguage (that is, academic language).

Well-developed Japanese language ability becomes more than a tool for everyday communication. It begins to function as the language children use to understand a subject and think about it.