3 ms·

The Magical Number 7 plus or minus 2

21 points by gabea 16y ago

mfukar 16y ago
Just as an anecdotal piece of info: most musicians accept that the human brain can keep track of eleven notes. Beyond that, you can change the scale progression and the transition will be (relatively) smooth to the human ear.
- gabea 16y ago
  That is really interesting.
- bryanh 16y ago
  Perhaps you could clarify or point me to some more information on this? Even as a (somewhat amateur) jazz musician, musical pivots have always eluded me.
  - mfukar 16y ago
    I've been searching for an interview with Jimmy Page, where he mentioned this and it's the first I've heard of it, but to no avail. Hence, 'anecdotal'. If I find it, I'll post it here.
- nimai 16y ago
  It's because eleven notes is the maximum that fit "nicely" into the harmonic series our eardrums pick up: http://en.wikipedia.org/wiki/Harmonic_series_(music) http://en.wikipedia.org/wiki/Harmonic_series_(music)
Jun8 16y ago
I have always been somewhat skeptical of the fact that this number coincides so nicely with the number of digits in a phone number, which the subjects (I presume to be from the US, I know, I have to track down and read the paper) are highly trained to commit to short term memory. Does anyone know of similar finding were found in experiments with diverse cultures?
- PStamatiou 16y ago
  phone numbers also play into the concept of chunking http://en.wikipedia.org/wiki/Chunking_(psychology) http://en.wikipedia.org/wiki/Chunking_(psychology)
- o_nate 16y ago
  This is kind of a chicken-and-egg problem, isn't it? Which came first: the ability to remember 7 digits, or the decision to make phone numbers 7 digits long? It seems more likely that 7-digit phone numbers became common because that was the highest number of digits that most people could remember.
  - erikano 16y ago
    I believe that there is some truth to the claim that the length of a phone number affects our ability to remember numbers of that length; in Norway, we have 8 digits in our phone numbers. A couple of years ago, I decided to try and remember as much of Pi as I could, and I found that precision to which I could remember it, was in fact 8 decimal digits. Even though I have only been asked to recite as much of Pi as I could remember once during the last year, and I seldom actively try to remember it, whenever I come to think of Pi, 3.14159265 usually pops into my mind. However, whereas I remember telephone numbers either grouped on the form 12 34 56 78 (twelwe-thirtyfour-fiftysix-seventyeight) or 123 45 678 (hundredandtwentythree-fourtyfive-sixhundredandseventyeight), I remember Pi as a sequence of digits (three-comma-one-four-one-five-nine-two-six-five). Edit: The two ways of grouping the digits in a phone number that I mention here, is the way that phone numbers are usually written here in Norway. Often, landline phone numbers are written on the form xx xx xx xx and cellphone numbers on the form xxx xx xxx. (Additionally, if I remember a phone number on one form, and someone else says the same number on the other form, I find it hard to tell whether we are speaking of the same number).

21 points by gabea 16y ago

Just as an anecdotal piece of info: most musicians accept that the human brain can keep track of eleven notes. Beyond that, you can change the scale progression and the transition will be (relatively) smooth to the human ear.

gabea 16y ago
That is really interesting.
bryanh 16y ago
Perhaps you could clarify or point me to some more information on this? Even as a (somewhat amateur) jazz musician, musical pivots have always eluded me.
- mfukar 16y ago
  I've been searching for an interview with Jimmy Page, where he mentioned this and it's the first I've heard of it, but to no avail. Hence, 'anecdotal'. If I find it, I'll post it here.
nimai 16y ago
It's because eleven notes is the maximum that fit "nicely" into the harmonic series our eardrums pick up: http://en.wikipedia.org/wiki/Harmonic_series_(music) http://en.wikipedia.org/wiki/Harmonic_series_(music)

Jun8 16y ago

I have always been somewhat skeptical of the fact that this number coincides so nicely with the number of digits in a phone number, which the subjects (I presume to be from the US, I know, I have to track down and read the paper) are highly trained to commit to short term memory. Does anyone know of similar finding were found in experiments with diverse cultures?

PStamatiou 16y ago
phone numbers also play into the concept of chunking http://en.wikipedia.org/wiki/Chunking_(psychology) http://en.wikipedia.org/wiki/Chunking_(psychology)
o_nate 16y ago
This is kind of a chicken-and-egg problem, isn't it? Which came first: the ability to remember 7 digits, or the decision to make phone numbers 7 digits long? It seems more likely that 7-digit phone numbers became common because that was the highest number of digits that most people could remember.
- erikano 16y ago
  I believe that there is some truth to the claim that the length of a phone number affects our ability to remember numbers of that length; in Norway, we have 8 digits in our phone numbers. A couple of years ago, I decided to try and remember as much of Pi as I could, and I found that precision to which I could remember it, was in fact 8 decimal digits. Even though I have only been asked to recite as much of Pi as I could remember once during the last year, and I seldom actively try to remember it, whenever I come to think of Pi, 3.14159265 usually pops into my mind. However, whereas I remember telephone numbers either grouped on the form 12 34 56 78 (twelwe-thirtyfour-fiftysix-seventyeight) or 123 45 678 (hundredandtwentythree-fourtyfive-sixhundredandseventyeight), I remember Pi as a sequence of digits (three-comma-one-four-one-five-nine-two-six-five). Edit: The two ways of grouping the digits in a phone number that I mention here, is the way that phone numbers are usually written here in Norway. Often, landline phone numbers are written on the form xx xx xx xx and cellphone numbers on the form xxx xx xxx. (Additionally, if I remember a phone number on one form, and someone else says the same number on the other form, I find it hard to tell whether we are speaking of the same number).