Why do most customers at my bookstore have trouble understanding my instructions to swipe their debit cards with the magnetic stripe “toward me?” Almost everyone positions their card the wrong way, then asks in confusion, “Stripe toward me?”—meaning themselves. What is causing everyone to make the same mistake?
—Michael Manchester, Aylmer, Ontario
Robert O. Duncan, a behavioral scientist at York College, the City University of New York, explains:
This debit-card mystery may seem insignificant (albeit intriguing), but it actually serves as an excellent illustration of how we store memories and why that system sometimes fails us.
In 1974 psychologists Alan Baddeley and Graham Hitch of the University of York in England proposed that we possess working memory, a space where new memories can be accessed and
manipulated. According to Baddeley and Hitch’s model, we store and alter memories through a phonological loop, which processes sound information, and through a visuospatial scratchpad, which maintains and manipulates spatial and visual information.
In the case of the debit-card stripe, the phonological loop comes into play because the cashier gives the customer verbal instructions. We use this loop all the time. For example, when trying to remember a telephone number, you probably rehearse the number in your mind by repeating the names of the numbers rather than picturing them.
Your customers are likely rehearsing the words “stripe toward me” so they can remember the command and act on it. A problem occurs, however, when the customer interprets “stripe toward me” literally. This happens because the phonological loop only serves to keep a phrase fresh in your memory—it does not help you intelligently interpret its meaning. Rehearsing the pronoun “me” over and over can alter your interpretation of the instruction, believing the “me” refers to yourself instead of the cashier.