Skip to main content

Articles

How many words do you need to learn?

An analysis of English vocabulary* has found that the first 1000 words account for 84.3% of the words used in conversation, 82.3% of the words encountered in fiction, 75.6% of the words in newspapers, and 73.5% of the words in academic texts. The second 1000 accounts for about another 5% (specifically, 6% of conversation, 5.1% of fiction, 4.7% of newspapers, 4.6% of academic texts).

The conventional view of brain development has been that most of this takes place in utero and in the first three years, with the further development continuing until the brain is fully mature at around 10-12 years of age. The turbulence of adolescent behavior has been deemed to be mostly caused by hormonal changes. Piaget, who identified four stages of cognitive development, assessed that his highest stage — that of formal, abstract reasoning — occurred around 13-14 years (although not everyone reaches this level, which requires appropriate education).

To use a strategy effectively, you need to understand why it works, how it works, when it works and when it doesn’t.

For example, all students take notes — not everyone knows how to do it well. Research into the effectiveness of note-taking has found — surprise, surprise — that sometimes note-taking helps you remember information, and sometimes it doesn’t1.

I recently reported on a finding that memories are stronger when the pattern of brain activity is more closely matched on each repetition, a finding that might appear to challenge the long-standing belief that it’s better to learn in different contexts. Because these two theories are very important for effective learning and remembering, I want to talk more about this question of encoding variability, and how both theories can be true.

On my walk today, I listened to a downloaded interview from the On Being website. The interview was with ‘vocal magician and conductor’ Bobby McFerrin, and something he said early on in the interview really caught my attention.

Research has found that people are most likely to successfully apply appropriate learning and remembering strategies when they have also been taught general information about how the mind works.
The more you understand about how memory works, the more likely you are to benefit from instruction in particular memory skills.
When you have a good general understanding of how memory works, different learning strategies make much more sense.

Consider our facts about blood:

  • arteries are thick and elastic and carry blood that is rich in oxygen from the heart.
  • veins are thinner, less elastic, and carry blood rich in carbon dioxide back to the heart.

We could, as is often advised, simply turn these into why questions. And we can answer these on the basis of the connections we’ve already made:

Why are arteries elastic?

Because they need to accommodate changes in pressure

Why are arteries thick?

Because they need to accommodate high pressure

The Proto-Indo-European language (PIE) is the ultimate ancestor of many European and Indian languages. The word "proto" indicates it was spoken thousands of years in the past and we have no direct record of it. What we do have is the clear evidence in its descendant languages, from the consistent patterns in the way their words vary, that there was such an ancestor. Following these patterns, scholars have deduced a quite extensive vocabulary — but they are still reconstructed, not ‘real’ words. We can never know exactly how these words were pronounced, or precisely how they were used.

Genes

Several genes have been implicated in Alzheimer's, but the big one is the e4 allele of the ApoE gene (on chromosome 19). This variant is found in about a quarter of the population.

Having it doesn't mean you are foreordained to develop Alzheimer's, but it certainly increases the risk substantially. The risk goes up considerably more if both of your genes are the e4 variant (remember you inherit two: one from each parent).

In a 1987 experiment (1), readers were presented with a text that included one or other of these sentences:

or

Both texts went on to say: