The acquisition of vocabulary:

"People don’t acquire vocabulary by rote learning. They don’t memorize word lists and definitions by drill and repetition. Virtually all of one’s vocabulary is acquired by hearing or reading words in a context from which one can infer their meaning. One might have to en­counter a word used in several different contexts to be able to infer its complete meaning and its subtle difference from some similar word (e.g., charitable and generous). Brighter persons infer more of a word’s meaning from any given context and don’t need as many encounters with it in different contexts to grasp its distinctive meaning. Given similar amounts of exposure to the language, therefore, a more in­telligent person acquires a larger, qualitatively richer, and more subtle vocabulary than a less intelligent person."

Straight Talk About Mental Tests

Arthur R. Jensen (1981)

[See also: 1,2,3,X]