Most of the world's languages are spoken languages; that is, their speakers use acoustic signals produced by the vocal tract to represent meanings. Different groups of humans use different vocal signals. For instance, among English speakers in America, the vocal signal for the concept the child in our example has in mind sounds roughly like /kuki/; among English speakers in Europe, roughly like /biskit/; among German speakers, roughly like /keks/. In general, the association between the vocal signal and the concept is arbitrary; in other words, nothing in the form suggests the associated meaning. For instance, the concept of silence is not expressed by a period of silence, nor are 'whisper' or 'shout' necessarily expressed in a whisper or a shout, or even quietly or loudly. There are some exceptions to the arbitrary character of morphemes. For instance, if the concepts to be encoded are a sneeze or the characteristic sound of a cat, the vocal signals /etSu/ or /miao/ mimic real-world instances of those concepts. But such examples of sound mimicry (also known as onomatopoeia) are fairly narrowly restricted, and they are not central to spoken languages.
Acquiring spoken language depends not only on the ability to produce vocal signals, but on the ability to perceive them as well. There are visual and other sensory cues associated with at least some vocal signals (notably the ones produced towards the front of the mouth), but the most reliable cues are acoustic. Therefore, if a child has trouble perceiving or otherwise interpreting the acoustic cues for vocal signals, the acquisition of spoken language is difficult, if not impossible. However, like biological instincts in many other species (for instance, the imprinting in the geese described by Konrad Lorenz), the human language instinct is abstract and therefore superficially malleable. In particular, the encoding ability (the ability to pair forms with meanings) does not require the linguistic forms to be audible signals produced by movements of articulators in the vocal tract. Instead, the forms can be visible signals produced by movements of other articulators, notably of the hands and face. Languages that use such visible signals are known as sign languages. For people with neither sight nor hearing, there are even languages that use tactile signals.
As mentioned earlier, the form-meaning association for morphemes in spoken languages is generally arbitrary, and any non-arbitrary origins are lost in the proverbial mists of time. Sign languages are more recent, and the form-meaning associations are often more accessible to us. This is because signers, faced with the communicative problem of encoding mental concepts by means of visual signals, naturally tend to choose signals whose visual form suggests the intended meaning. Such signs are called iconic (because the form-meaning relation is reminiscent of the relation between an icon and what the icon represents) or motivated (because the form-meaning relation is motivated by analogy).
It is worth examining in a bit more detail how iconic signs might emerge. We begin by considering an apparently unrelated problem - a classic problem in game theory. The point of the game is to meet someone you don't know tomorrow in New York City. You and your partner (let's call him Jim) need to coordinate a time and place to meet, but you are not able to communicate before you meet. If you meet, you both win the game; if not, you lose. What time and place do you choose? What are your considerations?
Here is Jim's solution. Jim has been to New York once in his life. This was on the occasion of his engagement to his significant other a few years back, which took place at a little restaurant in Greenwich Village at 6 p.m. He fondly recalls that dinner as one of the high points of his life, and so he chooses the restaurant and 6 p.m. as his meeting coordinates.
Your solution is probably not as foolish as Jim's. Clearly, in choosing your coordinates, you need to make choices that are salient, but not just to you. You need to also take into account your partner's state of mind, including that person's expectations about your own state of mind. Jim is completely unrealistic to expect a complete stranger to know details about his engagement. As it turns out, most people are not like Jim and are instead quite successful at finding points of convergence even in the absence of communication. Thomas Schelling, the originator of the "meet me in New York" game and a central figure in the history of game theory (Schelling 1960), called such points focal points; they are also called Schelling points in his honor.
Schelling points are not necessarily unique. Indeed, if they were, the "meet me in New York" game would be pointless. Instead, it does have and make a point - namely, that given the vast number of times and places available to meet in principle, people are able to severely restrict the set of possible options based on what they think another person might be thinking.
Now imagine another coordination game. Here, the meeting point is not in physical space, but in conceptual space. The point of the game is to get your partner to meet you at a concept of your choice. In other words, you think of a concept and try to get your partner to think of the same concept. How would you do this for "candle"? Or "pig"? Or "three"? Or "trash"? All sorts of variants of the game are possible. The game is trivial if you get to use a language you share with your partner. But imagine that you are playing with a partner with whom you don't share a language, or that neither you nor your partner have any language at all. Imagine that the rules of the game don't permit you to draw. This last variant would virtually force you to use iconic gestures as Schelling points.
Now consider what would happen in a community of players who are repeatedly playing the "meet me at my concept" game with many different partners over time. The players in the community might be expected to converge on particular forms for the various concepts that they wish to convey, especially if they get bonus points for how quickly they can get their partner to home in on their concept. In other words, a community playing "meet me at my concept" will develop symbols that are conventional.
What does it mean for a symbol to be conventional? It means that the association between the symbol's form and its meaning is fixed; individual language users cannot change the associations at their pleasure, or even for good reason. In this respect, there is no difference between an iconic symbol that has become conventional and a purely arbitrary symbol. It is clear that in an effective system of communication, arbitrary symbols must be conventional - a point humorously illustrated in the passage from Lewis Carroll's Through the looking-glass where Humpty Dumpty assumes the right to associate ordinary forms like glory with non-conventional meanings like 'nice knock-down argument', much to Alice's puzzlement. What we are saying here is that something like the converse is also true - that with respect to a language user's freedom to associate form and content, conventionality is tantamount to arbitrariness. Before an iconic symbol becomes conventional, its symbolic force derives from the iconic character of the form-meaning association. In the emergence of a large-scale system of conventional iconic symbols, the relation among the various symbols becomes increasingly important. Specifically, the particular form of two symbols becomes less important than the fact that they are in contrast (= formally distinct from one another). We might therefore expect conventional iconic symbols to become subject to the same kinds of linguistic pressures of production and perception as are arbitrary symbols. Recall further that children are masters at acquiring large numbers of arbitrary symbols. The fact that humans are extremely comfortable with arbitrary symbols is underscored by the likely prevalence of multilingualism throughout most of human history. For instance, Jared Diamond describes the Papua New Guinean companions on his expeditions as speaking an average of five languages (Diamond 2012). So once a language acquires native speakers, the role of iconicity is weakened yet further.
Iconicity can weaken in two basic ways. First, a once-iconic feature
(such as a sign's handshape or location) may undergo change, in some
cases to the point of complete deletion. A case in point is the ASL
sign for HOME, a compound formed from EAT and SLEEP. SLEEP, originally
a B handshape at the ear, has assimilated to the flat O handshape of
EAT. (See
here
for ASL handshapes.) This type of loss of iconicity is described
extensively in The relatively weak role of iconicity for native signers is
illustrated by anecdotal evidence from our own
experience.2 One of us (Jami) is a
right-dominant native signer who learned ASL before English; the other
(Beatrice) is a left-dominant very late learner of ASL. Learning the
sign for JOT, Beatrice was struck by its iconicity: PUT (flat O hand) is
directed towards the classifier for FLAT-SURFACE (B hand). This was
news to Jami, who had never realized that the sign was a compound. Her
realization is exactly analogous to Beatrice's realization as an adult
that always is a compound of all and ways. Another
example concerns signs related to clocks and calendars. HOUR is
produced with a dominant G hand moving in a circle against an upright B
hand. For right-dominant signers, the dominant hand's index finger
moves outward from the speaker, and the tip of the index finger traces
the path of the hour hand of an analog clock. What happens for
left-dominant speakers? If iconicity trumps outward movement, the index
finger should move inward; if outward movement trumps iconicity, the
sign is no longer iconic. When Beatrice (using her rudimentary ASL)
asked Jami how to produce the sign as a left-dominant signer, it took a
while to get across the point of the question. To a native speaker like
Jami, the only feature of the sign that was salient was the articulatory
feature 'outward'; the fact that outward movement combined with left
dominance results in a countericonic sign was completely irrelevant to
Jami. The same issue arises in connection with a sign like WEEK,
produced by moving a dominant G hand across the upward-facing palm of a
nondominant B hand from the base of the palm to fingertips. Assuming a
conventional calendar layout, the sign is iconic for right-dominant
signers in that the dominant hand moves from early days of the week to
later ones. For left-dominant signers, the sign is once again
countericonic, since the dominant hand moves from right (late) to left
(early). In EVERY-MONDAY (M moves straight down) followed by
EVERY-TUESDAY (T moves straight down), EVERY-TUESDAY is signed slightly
outside of EVERY-MONDAY. As in the previous examples, the sequence is
iconic for right-dominant signers and countericonic for left-dominant
signers.
We have just seen that the articulatory feature 'outward movement'
trumps iconic considerations in the case of clock and calendar signs.
It is worth noting that these signs are relatively weakly iconic. What
we mean is that the layout of calendars and the direction of writing
more generally is not necessarily left to right. Neither is it
logically necessary for the hands of a clock to move in a clockwise
direction. The reason they do is that a clock's hour hand represents
the gnomon of a sundial, whose shadow moves in a clockwise direction
because of the direction that the sun appears to move in as a result of
the direction that the earth happens to spin in. Some signs, though,
are strongly iconic. For instance, in the signs for UP and DOWN, the
tip of the index finger points up and down, respectively. In principle,
it would be possible for the sign for UP to point down, and vice versa,
but this would be confusing at a very basic level. One might be tempted
to conclude from this that UP and DOWN are purely iconic signs, but that
conclusion would not be well-founded. In this connection,
consider
| Table 1: The Stroop effect with congruent and incongruent colors | ||
|---|---|---|
| blue | green | red |
| blue | green | red |
Both rows contain the arbitrary symbols blue, green,
and red. There is no question whether the forms of the words are
iconically related to the color they represent; they aren't. However,
in the first row, the color of the symbol's written form
is congruent with its meaning; in the second row, that is not the
case. A classic experiment (Jaensch 1929, Stroop 1935) shows that
people are faster and more accurate at reading color words and naming
their colors in the congruent condition, an effect known as
the Stroop
effect. The original reports of the Stroop effect involved color,
as in
At one time, it was thought that arbitrariness was a necessary property of human language (Hockett 1960). If this were true, the iconic aspects of signs like UP and DOWN would compromise the status of sign languages as true human languages. Among sign language linguists, one strategy in response to this threat has been to emphasize the role of onomatopoeia in spoken languages. We consider this a weak strategy, since onomatopoeia in spoken languages is marginal. In the discussion above, we have outlined what we consider a stronger strategy - one that relies on iconic symbols becoming structurally equivalent to arbitrary symbols in the emergence of a large-scale system of conventional symbols.
2. We are perfectly willing to grant iconicity an important role in the non-native acquisition of ASL. Such a role is consistent with the anecdotal evidence we present. It is suppported by the fact that ASL learning sites like Signing Savvy charge a premium for giving users memory aids for the signs on the site, which make reference to iconic properties.