Does it matter if you have a limited vocabulary?
Yes it does, according to this magnificent piece by E D Hirsch Jr:
Why should vocabulary size be related to achieved intelligence and real-world competence? Though the intricate details of cognitive abilities are under constant study and refinement, it’s possible to give a rough answer. The space where we solve our problems is called “working memory.” For everyone, even geniuses, it’s a small space that can hold only a few items in suspension for only a few seconds. If one doesn’t make the right connections within that space, one has to start over again.
Hence, one method for coping and problem solving is to reduce the number of items that one has to make sense of at any moment. The psychologist George A. Miller called that process “chunking.” Telephone numbers and Social Security numbers are good examples. The number (212) 374-5278, written in three chunks, is a lot easier to cope with than 2123745278.
Words are fantastically effective chunking devices. Suppose you put a single item into your working memory—say, “Pasteur.” So long as you hold in your long-term memory a lot of associations with that name, you don’t need to dredge them up and try to cram them into your working memory. The name serves as a brief proxy for whatever aspects will turn out to be needed to cope with your problem.
The more readily available such proxies are for you, the better you will be at dealing with various problems. Extend this example to whole spheres of knowledge and experience, and you’ll realize that a large vocabulary is a powerful coping device that enhances one’s general cognitive ability.
... it’s important to grasp the extreme difficulty of narrowing the verbal gap between advantaged and disadvantaged students. The problem has been called the Matthew Effect, an allusion to Matthew 25:29: “For unto every one that hath shall be given, and he shall have abundance: but from him that hath not shall be taken away even that which he hath.”
Advantaged students who arrive in the classroom with background knowledge and vocabulary will understand what a textbook or teacher is saying and will therefore learn more; disadvantaged students who lack such prior knowledge will fail to understand and thus fall even further behind, relative to their fellow students. This explains why schooling often fails to narrow the gap and may even widen it.
... How-to-ism has failed because of its fundamental misconception of skills, which considers them analogous to automated processes, such as making a free throw in basketball. In English class, young children are now practicing soul-deadening how-to exercises like “finding the main idea” in a passage and “questioning the author.”
These exercises usurp students’ mental capacity for understanding what is written by forcing them to think self-consciously about the reading process itself. The exercises also waste time that ought to be spent gaining knowledge and vocabulary. The increasingly desperate pursuit of this empty, formalistic misconception of reading explains why our schools’ intense focus on reading skills has produced students who, by grade 12, can’t read well enough to flourish at college or take a good job.
Read the whole thing to grasp the breadth and intelligence of the arguments that demolish vast chunks of modern education theory.
Oddly enough the author takes an apparently unfamiliar 'difficult' word - excrescence - and uses it to make a point about how you might work out from different contexts what it means. He does not mention that if you know Latin it's easy: cresco (to grow) and ex (out from).
Reading one's Wodehouse also does the trick.
All of which goes to explain just how far we face a civilisational disaster from the sheer scale of illiteracy among people who have been through our expensive education system and can still barely read:
According to the Trust, more than 5.2 million adults in England are categorised as functionally illiterate, meaning that they have literacy levels lower than those expected of an 11-year-old. Furthermore, the trust found that 17% of children say they would be highly embarrassed if their friends saw them with a book; more than half of the children questioned prefer watching TV than reading; and one in three children do not own any books at all.
The policy drama here is simple. In its efforts to give all children a decent start in life through madatory education, the state has standardised learning methods across the country and unerringly hit upon methods that for tens of thousands of children simply do not work. Add to that the formidable problems created by our having to organize classrooms to cope with thousands of immigrant children who may scarcely speak English at all, and you create all the conditions for a terrible mess.
When parents opt out of this state-controlled squalour by 'going private' (if they can afford it) they get denounced as snobs or elitists or whatever. But if I not unreasonably want my daughter to learn some French and Latin and Greek and to write well in English by the time she is 13 (as I do), what options do I have? Am I not infringing her human rights by putting her into a state system that can not even guarantee to get her to a modestly respectable reading level?
As I have written before, it's all a clear-cut case of something never seen before in human history: Suilinguicide.