Seeing Seven

I finished listening to The Tipping Point by Malcolm Gladwell today. It was one of the most thought-provoking books I have ever read. Here is something that he talked about that was pretty amazing.

Have you ever wondered how many items you can see without counting? I mean, when you look at three apples, you know there are three apples without having to count, "One--two--three!" But if you have fifteen apples, you probably would have to count the apples to know how many there are (unless you're an autistic savant or something like that). It turns out that the average person can see six or seven things without having to count. That's why dice are so effective. We can see the six dots without having to count each dot. That's why 12 or 20 sided die use numerals instead of dots. Imagine if we had to count each dot to figure out if we rolled a 17 or an 18. This is also why phone numbers are seven digits long. Alexander Graham Bell wanted to have a phone numbers long enough to have as many phone numbers as possible, but after about 9 or 10 numbers people began making more mistakes.

This idea of our brain having a limit for processing information also applies to our emotions. If you think about how many people you are really close to (meaning how many people you feel close enough to that you would be truly devastated if they passed away), the number is roughly 12. We usually have about 150 acquaintances. Crazy, huh? We have these natural groups that we are wired for.