My dad speaks with a German accent. Or so I am told. I can't hear it. Nothing unusual about that. But this is an instance of a very important, yet poorly understand, human phenomenon: the Variation Effect (as I'll call it).
To bring the Variation Effect into focus, consider some examples:
How does one pronounce the word "thursday?" Well, they do it one way in London's cockney East End, and a different way in afro-caribbean Brixton. Different pronunciations abound in Brisbane, Brooklyn, Ashville, and British Columbia. There is no one way to say "thursday," or any other word for that matter.
Variety occurs not only at the level of regions and populations. The next time you are at a table with friends, or sitting at a bar, or in a shop, pay attention to the way people talk. You'll notice surprising variation in inflection, emphasis, contraction, rhythm, melody, volume, timbre, etc.
In fact, it's variation all the way down, even at the level of the individual. You choose your words and articulate your speech one way when you're talking to an elderly man in the nursing home, and another way when you're addressing students from the podium, or when you're discussing the quarterback's performance with other fans at the stadium. What counts as stylish, thoughtful, polite, sensitive, respectful, funny, generous varies from one setting to another, depending on, among other things, to whom you are talking, whether the conversation is professional, and so on. It is mark either of stupidity or arrogance to be unable or unwilling to accommodate one's manner of speech to the circumstances in which one finds oneself.
As variation plays a central role in biological evolution, it also plays a fascinating role in the evolution of languages, as Guy Deutscher tells in his delightful book The Unfolding of Language.
Consider: The French say pied, whereas we say foot. They say pere, where we say father. To our for, they have pour, and where we say first, they say premier. Systematically there is a correspondence between words with p sounds in French and words with f sounds in English. What explains this, say historians of language, is that the French and English languages descend from a common ancestor. For various reasons the French, but not the English, preserves the more ancient p-sound pronunciations that would have been used in this ancestral tongue. At some point in the last four hundred years or so, speakers of languages such as English, German and Danish, but not speakers of French, Italian and Spanish, started to say f whereas earlier we said p.
How did this transition from happen? What's remarkable is that the change goes unmentioned in the historical record. How can this be? First, how can people have failed to notice and remark on a steady systematic change in the way people talk? And second, how could they have failed to shut it down. Speakers love to criticize mispronunciation, and surely that's what saying f for p would have sounded like, a big error!
One hypothesis is that the change was imperceptible because it was gradual. As Deutscher explains, leading linguists as recently as the middle of the last century thought this gradual-change thesis was plausible. But it isn't. It's ludicrous. As Deutscher remarks, there's p, there's pf, and there's f. How is gradual change supposed to mask those contrasts? You can hear the difference, can't you?
Some ideas are beautiful and the explanation Deutscher offers is a very beautiful indeed. The very question — why didn't people notice the sound change when it happened? — relies on the tacit assumption that there was ever a single way people pronounced the words in question. But there is no one way to pronounce these words or any other. The ground of linguistic reality is comprehensible variation. And so there never was a single or unified sound change.
Then what happened? All there is and ever was is variation, but what does change, over time, is the frequency of different forms or pronunciations across the field of variations. People didn't change the way they talked. What changed was the number of people who talked one way relative to those who talked another.
And this explains why we didn't notice the sound change. This is an example of the Variation Effect. We have great facility adapting to, accommodating and ignoring variation.
Did you notice when "bad," in the mouths of certain speakers, starting meaning "good," or, to go back in time, when "cool" started to mean stylish and positive? I hear my student describe a book as sweet and I know he means something very different from what my mother would mean if she were to describe the very same book as sweet. We are fluent and adaptable when it comes to different ways of talking here and now, and so, with all the more reason, we are not nonplussed by changes in the frequency distribution of different ways of talking. Meaning changes are not one-off occurrences, like heart attacks. They are gradual shifts in the behavior of lots of people against a background of unceasing variation.
Or consider a visual example: What does this tomato look like? Well, it looks one way from up close, when I hold it in my hand. It looks entirely differently when I look at it from across the room, or when it is sitting on a pile of two hundred tomatoes in the grocery store. And so likewise, its color looks one way under the store's fluorescent overheads and entirely differently in day light, or in the yellow tungsten lighting in the kitchen at home.
How does it really look? There's no such thing.
The point is not that the tomato isn't really red, or that there isn't in fact a single word thursday. It's that to perceive entities or properties such as these is to be knowledgeably or skillfully sensitive to patterns or stuctures of variation — to the ways how things look, or how words sound, predictably changes as circumstances change.
To perceive a word is to perceive something that is, of its basic nature, open to varieties of ways of showing up. A word that could only be pronounced one way (by one person? on a single occasion?) would not be a word at all. And to perceive a colored object is to understand — practically, not intellectually — that how it looks would vary in reliable ways were the lighting, or one's angle of viewing, to change. That's just what it is to have a certain color. It's to be a locus of possible visual variation of a certain style.
To perceive or cognize the world at all is to be sensitive the way patterns of variation allow for invariance to show up for us. We achieve access to that which is invariant (the color, the word) not because we are blind to variation, but because we are so fluent in our mastery of variation that we can let it recede for us and rest in the background.
And this fluent mastery of ever-present variation — the Variation Effect — is the hallmark of understanding.