Words are our greatest tools. They allow us to guide, warn, praise and admonish each other and to cooperate in complex tasks. Even restricting ourselves to oral traditions, we can pass down stories which preserve some of the wisdom of our ancestors. Once we master the art of reading and writing we can supersede the restrictions of memory and draw on the wisdom of successive generations. Knowledge is power, and the accumulated knowledge of many centuries is the most powerful of all.
Vocabulary acquisition is an enthralling process to study, as children learn the rules of grammar, and sometimes apply them with greater consistency than the idiosyncrasies of actual spoken adult language would deem correct, if you have gotted the point. Children may refer to little rodents as “mouses” because children have noticed a language rule, and applied it correctly. The English language is not always correct, for idiosyncratic and historical reasons. The English who goed West on the Mayflower were full of reformist zeal, and managed to improve the unwritten constitution by writing it down, and improved writing by removing some of the colourful miss-spellings of the English language and by making spelling more logical and less colorful, but they did not get round to a full purging of languistic errors and exceptions, or at the very least they have not gotten round to it yet (this is a recondite joke, because all English speakers at that time said “gotten” and then with time the English moved to “got” for the past tense, no doubt just to aggravate the colonials).
Some people have the simplistic notion that vocabulary must be determined by mere exposure to spoken language. That is necessary, but far from sufficient, as even children work out. They notice patterns, informal rules, and the contexts in which communication takes place. “The acquisition of meaning is based on the eduction of meaning from the contexts in which the words are encountered”. (So, even if the word “eduction” in the quotation from page 146 of Jensen’s “Bias in mental Testing” is unfamiliar, you will not be surprised to deduce that it means “To assume or work out from given facts; deduce”). The meaning of a word is acquired in some contexts which permits at least some partial inference as to its meaning. By hearing or reading the word in different contexts, through a process of generalization, discrimination and eduction one can guess at the essence of the meaning of the word, so as to use it (experimentally) oneself the next time a similar context presents itself. Words move from being unfamiliar to familiar, from familiar but not really understood to being familiar and partly understood (at which stage the explanations given about the meaning of the word are threadbare and inaccurate), and from there to being explained by use of synonyms (though those can range from partial to full understanding as shown by power of the explanations and definitions).
Testing vocabulary precisely is quite complicated, because you have to test how well subjects really understand the words in question. It is a bit like trying to find out whether people can really handle heavy machinery, as opposed to boasting about it. Typically vocabulary tests work up from common to rare words, and specify what sorts of definitions and explanations will get full points. On multiple choice questions, the use of distractor items often reveals that many people have misunderstood the meanings of words that are new to them. For example, some people who think they know how to define FATUOUS are distracted by the option large. An argument may be witless, silly and pointless, but not obese.
A very short vocabulary test, which correlates 0.71 with IQ, is the ten word test in the General Social Survey (US). Can something so crude yield interesting results? Yes. Razib Khan has a very informative post on this. In my view, no survey should be conducted without including a test like this, which provides a very good estimate of intelligence.
A stab at using this test to calculate the intellectual demands of particular jobs is provided by The Audacious Epigone. Note the low score for academics.
Nonetheless, long vocabulary tests, or dynamic computer—administered tests which adapt quickly to your difficulty level provide reasonable estimates of your total word store. In that sense, intelligence ranges from 0 to 45,000 words (the real upper limit if one avoids technical jargon), and one can put a single number on it, on a proper ratio scale. Rating people by the size of their word stores makes sense. Although 3000 words will provide a great deal of cost-effective and very useful communication, additional words bring conceptual benefits. Knowledge of the 3000 most frequent words in the English language will probably result in your understanding 95% of what is said to you, and knowledge of 5000 “word families” (the main word and its variants, like quick: quickly, quicker, quickest) should mean that you would be able to understand 99.9%. Why have more? The answer is that much of good thinking depends on a powerful vocabulary. Carpentry can be done with a standard tool set, cabinet making requires finer, more specialised tools.
As a rough guide, teenagers have about 12,000 words and college students 17,000. Older adults have 17,000 to 21,000 words, and a minority have many more. Some conceited person referred to 20,000 words as being “the incoherence boundary”. I eschew such contemptuous judgements.
Bright children acquire vocabulary faster than duller children, and thus brighter adults have larger vocabularies, because they require fewer contexts to work out word meanings, and make more subtle discriminations in meanings between similar words. In 1962 Alice Heim, to whom a statue should be raised somewhere, designed a new test of verbal reasoning called “The word in context”. Charming and intriguing, it featured an unfamiliar foreign word in a descriptive paragraph. Subsequent paragraphs gave more descriptive context, until the elusive meaning was potentially resolved. A brilliant idea, but the test took too long for it to be used in psychometry.
Most crucially, bright people often observe things and have thoughts about things before they learn the words they need to express them. They have the need before the word, so that when the word comes into view they seize on it with pleasure, and relief. Such words are treasured, and stick in the mind because of their elegant utility. Words for which we have no need are shapeless, and never stick in the mind.
So, a word is not just something we have heard, like a bird-song. A word is a cog in a meaning machine. To learn a word is to mine the essence of a context, to condense a cloud of implications into the condensate of definition.
You may wish to discuss this post with someone you love. Be warned: even in autochthonous pairings, discrepancies in terpsichorean accomplishments can lead to uxoricide.
Do not be captious after reading this post.