My seventh-grade English teacher exhorted us to study vocabulary with the following: "We think in words. The more words you know, the more thoughts you can have." This compound notion that language allows you to have ideas otherwise un-haveable, and that by extension people who own different words live in different conceptual worlds -- called "Whorfianism" after its academic evangelist, Benjamin Lee Whorf -- is so pervasive in modern thought as to be unremarkable.
Eskimos, as is commonly reported, have myriads of words for snow, affecting how they perceive frozen percipitation. A popular book on English notes that, unlike English, "French and German can distinguish between knowledge that results from recognition ... and knowledge that results from understanding." Politicians try to win the rhetorical battle ("pro-life" vs. "anti-abortion"; "estate tax" vs. "death tax") in order to gain the political advantage.
For all its social success, Whorfianism has fared less well scientifically. Careful consideration of the examples above shows why. Try calling dry snow "dax" and wet snow "blicket," and see if you notice a change in how you think about snow. I didn't. The English book's statement assumes that if you don't have a word for something, you can't talk about it ... a claim that the sentence proves false. Finally, calling the law of October 26, 2001 the "USA Patriot Act" may have done as much to stain the word "patriot" as increase enthusiasm for the law.
Oh, and Eskimos don't have all that many words for snow.
In fact, scientists have had so much difficulty demonstrating that language affects thought that in 1994 renown psychologist Steven Pinker called Whorfianism dead. Since then, Whorfianism has undergone a small resurgence. For instance, Lera Boroditsky and colleagues found that speakers of Russian, which treats light blue and dark blue as primary colors, are faster to categorize shades of blue.
While fascinating and important work, these and other similar results are a bit short of showing that "the more words you know, the more thoughts you can have." The recent study that comes closest is an investigation of number.
Although number words and counting are a fixture of life in most cultures from the time we are old enough to play hide-and-go-seek, some languages have only a handful of number words. In a paper published in 2008, MIT cognitive neuroscientist Michael Frank and colleagues demonstrated that Pirahã, a language spoken by a small Amazonian community, has no number words at all. The research team simply asked Pirahã speakers to count different numbers of batteries, nuts and other common objects. Rather than having a word consistently used to describe "one X" a different word for "two Xs" and yet another word for "three Xs," the Pirahã used hói to describe a small number of objects, hoí to describe a slightly larger number, and baágiso for an even larger number. Basically, these words mean "around one," "some" and "many."
The lack of number words had a profound and surprising effect on what the Pirahã could do. In a series of experiments, the researchers presented Pirahã participants with some number of spools of thread. The participants' task was simply to give the researcher the same number of balloons. If the participants were allowed to line up the balloons next to the spools of thread one-by-one, they did fine. But if they weren't allowed this crutch -- for instance, if the spools of thread were dropped into a bucket one at a time, and then the participant had to produce the same number of balloons -- they failed. Although they were generally able to stay in the ballpark -- if a lot of spools went into the bucket, they produced a lot of balloons; a small number of spools, a small number of balloons -- their responses were basically educated guesses.
Could it be that the Pirahã not understand the concept of "same amount"? That's unlikely. When allowed to match the balloons to spools one-by-one, they succeeded in the task. Instead, it seems that they failed to give the same number of balloons only when they had to rely on memory.
This actually makes a lot of sense. Try to imagine exactly seventeen balloons in your head, but without counting them. It's impossible. Decades of research have shown that people can tell the difference between one object and two or between three objects and four without counting, but such fine distinctions with larger numbers like seventeen versus eighteen requires counting. You wouldn't match seventeen balloons to seventeen spools by sight alone. You would count the spools and then count out the same number of balloons.
But the Pirahã can't count. They don't have number words.
This suggests a different way of thinking about the influence of language on thought: words are very handy mnemonics. We may not be able to remember what seventeen spools looks like, but we can remember the word seventeen. In his landmark The Language of Thought, philosopher Jerry Fodor argued that many words work like acronyms. French students use the acronym bans to remember which adjectives go before nouns ("Beauty, Age, Number, Goodneess, and Size"). Similarly, sometimes its easier to remember a word (calculus, Estonia) than what the word stands for. We use the word, knowing that should it becomes necessary, we can search through our minds -- or an encyclopedia -- and pull up the relevant information (how to calculate an integral; Estonia's population, capital and location on a map). Numbers, it seems, work the same way.
I don't know whether my seventh-grade English teacher would be disappointed. Do more words mean more thoughts? Probably not. But more words do make it easier to remember those thoughts -- and sometimes that's just as important.