Interestingly, we're quicker at comparing numbers that are further apart, which seems to imply some intuitive sense of "number line" -- and our number line perhaps has some sort of strange metric (not the usual one) in which the distance between 2 and 3 is longer than the distance between 7 and 8, since we're faster at saying 3 is larger than 2 than we are at saying 8 is larger than 7. (See, for example, yesterday's post on hyperbolic discounting which exploits a similar phenomenon with respect to timelines.)
And here's an interesting fact:
Because Chinese number words are so brief—they take less than a quarter of a second to say, on average, compared with a third of a second for English—the average Chinese speaker has a memory span of nine digits, versus seven digits for English speakers. (Speakers of the marvellously efficient Cantonese dialect, common in Hong Kong, can juggle ten digits in active memory.)
I wonder if this sort of thing is true in general -- does this correlation extend beyond just a pair of languages? Wikipedia's article on the "seven plus or minus two" phenomenon backs this up -- the actual limit is something like two seconds of speech -- although unfortunately there's no citation to follow.
(Via Seed's Daily Zeitgeist.)