Red Light, Green Light

"What would happen if red means "go"?" Tommy asked me at age 3. We were stopped at a red stoplight, and he was pondering the issue. "Good question," I responded. "What would happen? Do you think everyone would run into each other?" "Maybe, if they didn't know that red means go."

While answering his question, what my mind was really thinking was "Aha! Arbitrariness of the sign!" He recognized that the fact that "red" means "stop" and "green" means "go" is an arbitrary convention, agreed upon by members of society. There's no real reason that red has to mean stop. We could indicate "stop" with purple, or orange, or brown. Red could mean "go" or "slow down" or "speed up". We've linked "red" with "stop" through convention. By asking what would happen if this were changed, Tommy was indicating that he recognized this as a convention, or as Ferdinand de Saussure (1857–1913) phrased it he recognized the arbitrariness of the sign.

Depebo, arbre, baum, tree - what do these words have in common? Nothing other than the fact that they mean the same thing in different languages. Each language has chosen its own set of sounds to link to that meaning. Thus the 'sign' (in this case the word) is an arbitrary link to the meaning. This arbitrariness of the sign is a crucial design feature of human language. With a few exceptions (onomatopoeia and sound symbolism), there is no relationship between a word's meaning and its sound. It just is. And that lack of relationship has given us the freedom to link many meanings to sound -- our language need not be grounded in reality. We can talk about ideas, fantasy or even the impossible. The arbitrariness of the sign has also made it possible for many different languages to come into being, each with their own unique links to concept and meaning.

Yet, the concept of arbitrariness of the sign isn't self-evident. 2 year olds, when asked what happens if you call a 'cat' a 'dog' will often respond with 'it'll bark' or something similar, suggesting that they think the cat becomes a dog. For them, word and the thing appear to be one in the same. A 4 year old, however, will say "that'd be silly" or "no one would understand you." They've begun to learn that words and things are separate. A word is just a label. And if it's a label, you can manipulate it. You can change it. You can represent it with sound. Or with letters. Or with a sign. Tommy's recognition that this relationship between red light and the meaning 'stop' is just a convention of society was an indication of growing metalinguistic awareness. Metalinguistic awareness is the ability to recognize the arbitrary and systematic nature of language, to be able to reflect on language and manipulate it, rather than just use the parts to communicate. And metalinguistic awareness turns out to be a crucial component of sophisticated language use – from everything to the ability to make jokes and puns to using metaphorical language to learning to read.

None of this thinking about metalinguistic skills, however, helped me to answer the next questions:

T: "Why does red mean stop?"
M: Well, it just does. It's a rule that everyone agrees upon so we don't run into each other. (Trying to phrase 'arbitrariness of the sign in 3 year old terms).
T: Who made the rule?
M: Umm.. I don't know.
pause
T: I think the stoplight guys made it.

Sounds good to me.