This article is part of a series entitled The Unlimited Mind. See also:
1. On Memory; 2. The Genius Within; 3. Coming soon
Have you ever tested your digit span?
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Read the 8-digit string above, then close your eyes and say it out loud. Were you successful? Try again with each member of this list. Better yet, get a friend to read each string out loud, and then say it back to them.
Digit span seems like a useless ability. Why would you want to test it? Well, surprisingly, digit span is highly correlative with general intelligence. And, as it turns out, 8 digits is a pretty good span. So, if you were successful at the task above, chances are you’re a pretty smart fellow.
How could a task as simple as repeating a digit string predict one’s IQ? Well, digit span tests working memory, which refers to the amount of information that can be stored in one’s brain at any given time. If someone can process more thoughts at a time—juggle more balls, so to speak—he will be able to make deeper connections and think more abstractly. Note that working memory can store all kinds of information—sounds, images, and even ideas. How did you complete the digit span task? You might have just repeated the sounds of the numbers. Or, maybe you pictured shapes of the numbers in your mind. Or maybe you used a combination of these and other techniques. It’s not too hard to imagine that one who can process many sights and sounds simultaneously will excel at activities we commonly deem as requiring intelligence.
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