Friday, 13 June 2008

Jokes and their relation to my unconscious, part one

My psychology degree course lasted three years. In all that time, there were just three ‘jokes’ in the lectures and reading. (As the terrriblest of students, I possibly missed a few more ‘jokes’ but I doubt it.)

I can still recall all three more than three decades later. So what were they and why do I remember them? Because they taught me something or helped me understand something significant. I call them jokes but they’re not really jokes, more witticisms. But, isolated in the oceans of aridity that make up a psychology degree, they seemed as funny as Groucho Marx or Chris Rock.

So here is the first of those three ‘jokes’ and its significance — ie why I still remember it. And why you probably will, too, now.

e one (in which we understand phone numbers)

The Magical Number Seven, Plus or Minus Two. That’s the witty title of a 1956 paper by George A Miller. Not only is it one of the very, very few wittily titled psychology papers I’ve ever seen, it’s also one of the few academic papers which has had a major effect on everyone’s daily life.

Seven is Miller’s magical number because, as he showed, it’s the limit of the number of
things we can keep in our short-term memory — plus or minus two things, that is. Short-term memory is the really brief one — two seconds. That’s how long we can easily retain a list of random letters or words or digits. The subtitle of his paper is : Some Limits on Our Capacity for Processing Information.

It’s the fact of an effective seven-thing working memory limit which took Miller’s paper to the world — and stuck it in my memory. Someone at the Bell Telephone company read it and realised that nearly everyone could stick a seven-digit phone number into their short-term memory — from which it could later be shunted into more permanent storage.

That seven-digit limit was copied round the world. Wilson Pickett sang that he could be reached on 634-5789. Scotland Yard became 944-1212. Link that seven-digit number to an area code — which we store as one chunk of information — and you still only get an eight-bit chunk, ie the magical number plus one.

It stayed that way, very happily for everyone, until telephone companies started to forget Miller’s paper. First came Paris, as far as I was concerned anyway. Sometime in the late 1980s or early 1990s, Paris numbers went to eight digits. I’d always been able to recall scores of numbers — I can still remember the number of a friend who lived in Basing Street more than thirty years ago. But even I struggled to stick these eight-digit numbers in my memory. I found it really hard to remember my friend Paul’s number.

Then London followed where Paris pioneered. Only this time, people cheated. What were meant to be eight-digit numbers, people t
urned back into seven-digit numbers, by moving the first digit of the number on to the area code. So 020 7916 4185 (an old number of mine) would become 0207 916 4185. Logically wrong, of course, but completely in accord with Mr Miller’s magical numbering system.

Nowadays, of course, we rarely bother to remember numbers. They’re either there in our speed dial or we look them up electronically faster than we can recall them. But Mr Miller’s magical number follows us there, too. Do you think it mere chance that there are seven items (Finder, File, Window, View, Go, Help) in the Apple menu? Why do you think it’s so hard to find your way across the Microsoft Word menu, which has twelve items?

Joke two (in which we learn a way to remember the basic rules of Mendelian genetics)

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