Read this shopping list, and then cover it with your hand:
Now, how many of the items can you remember without peeking? Give yourself a moment to recall as many of them as you can.
If you left out an item (or several), chances are good it wasn’t the bread or the gum, but rather something in the middle. And if that’s the case, congratulations, you have something in common with 19th century psychologist and memory pioneer Hermann Ebbinghaus.
At the time, the prevailing thought held that memory was impossible to study in any scientific fashion; it was simply too nebulous, too mysterious. Ebbinghaus disagreed. But since every single mind is different, how in the world would he eliminate confounding variables? His imperfect yet deeply elegant solution: to study only a single experimental subject—himself.
To collect his data, Ebbinghaus tested his own ability to memorize “nonsense syllables”, three-letter sequences which were technically pronounceable, but carefully chosen to convey no special meaning.
What he found resonates today.
For instance, have you ever wondered who first discovered the learning curve? (It’s not just an expression but a real, observed scientific concept: averaged over many trials, when you chart proficiency at a task against experience, the result is a rising curve, which then levels out.) The term doesn’t come from Ebbinghaus, but the careful graphs charting his progress were probably the first to clearly illustrate this phenomenon.
Ebbinghaus also brought us the slightly less memorable “forgetting curve,” which holds that we tend to lose recently-acquired information in a sort of exponential pattern—at first discarding great swaths of information which gradually levels out into a modest yet steady amount retained.
And finally, he also observed the serial positioning effect, aka the reason you likely remembered bread and gum but maybe tripped up over the yogurt or pickles. Basically, he found that when trying to recall items on a list, accuracy overall is largely a function of that item’s place within the list.
When attempting to remember his strings of nonsense words later, Ebbinghaus found he tended to lead with the beginning of the series and then secondly go for the end, while the middle of the sequence was most likely to be neglected by his memory. One theory suggests this is because by the conclusion of the list, we’ve had time to commit Item One to long-term memory, while that final item is still the freshest in our short-term memory.
While clearly, there are some issues with only studying a lone test subject, let alone choosing yourself, Ebbinghaus’s learning curve, forgetting curve, and serial positioning effect still hold true, whether you’re trying to recall nonsense syllables, that movie you saw last week, a conversation you had three days ago, or yes, even a grocery list.
It’s just something to keep in mind—if you can.