Selective amnesia: routinely forgetting familiar things

Alison Beard interviews UCLA professor Alan Castel for Harvard business Review:

It would be overwhelming and maladaptive to mentally record everything we see. So subconsciously we let some things fall away. The most famous experiment on this topic showed that few people can correctly recall the placement of the features on a penny—which way Lincoln is facing or where the word “liberty” goes. It’s a familiar object, yet we don’t focus on its details.

Other work has shown that the same is true for calculator keypads, computer keyboards, elevator buttons, and aspects of road signs. My colleagues Adam Blake and Meenely Nazarian and I thought that we might get different findings with the Apple logo. It’s also extremely familiar—nowadays maybe even more so than a penny—but it’s simpler. It’s designed to be aesthetically pleasing, and for many it’s a symbol of high value. But perhaps because it’s so ubiquitous and basic, our study subjects clearly hadn’t committed its details to memory. Only one got every part of the logo right, and just seven could draw it with three or fewer errors. And when we put the actual Apple logo in a lineup with seven altered versions, only 47% of people could identify it. We all know it looks like the fruit, but most of us don’t pay attention to the bite or the leaf. And that’s natural. We don’t burden ourselves with information we don’t think we’ll need to use.

I can draw the Apple logo as if I were tracing it. Then again, I can remember how many bars are in the IBM logo. Apparently there’s some part of my mind that believes the information will be important one day.