Human behavior: What's bugging you?

Annoyance captures elements of other emotions but belongs exclusively to none.

May 29, 2011 | By Joe Palca and Flora Lichtman

What annoys you? Traffic jams, car alarms, flight delays, phone trees, junk mail? People who cut in line? People who talk loudly on cellphones? People who eat noisily and clip their nails in public? You're not alone. These are just some of the irksome things we confront daily.

Since annoyances are ubiquitous, and so many people are annoyed so much of the time, you might think that science could offer some insights about why we find certain things so annoying and what we can do about them. In fact, science can. But don't ask a scientist. As a group, they have almost completely dropped the ball on this topic. In fact, if you talk to scientists, you might get the idea that there is no such thing as annoyance at all.

"From my perspective, annoyance is mild anger," says James Gross, a psychologist at Stanford University. Paul Rozin, a psychologist at the University of Pennsylvania, warns, "You have to be careful to distinguish annoyance from aversion." And University of Florida psychologist Clive Wynne says, "It's hard to distinguish annoyance from frustration."

It's true that annoyance shares qualities with anger, aversion and frustration. There is also some overlap with disgust, irritation, even ennui. But annoyance, as we who've felt it can attest, is its own thing. It captures elements of other emotions but belongs exclusively to none.

So it fell to us, two science journalists, to probe the findings of science for clues to what annoyance is all about. After talking with researchers in a variety of disciplines including (but not limited to) psychology, physics, acoustics, chemistry, molecular genetics, animal behavior and neuroscience, we have come up with a formula for what makes something annoying.

First, to be annoying, something must be unpredictable. This may be the heart of why cellphone conversations are so grating. Research shows that when we listen to speech, our brains try to predict the words that will come next. But it's hard to predict the next words out of someone's mouth when you're only hearing one side of a conversation. Research on this topic indicates you get drawn in more; you get more distracted from what you'd rather be doing or thinking about; the annoyance level rises.

Next, it must be unpleasant. This is a giant category, and often subjective. Some people are annoyed when someone picks a piece of lint off a garment they are wearing; others are grateful. Some are annoyed when radio announcers leave the "g" off words such "going" and "rolling"; others hardly notice.

While there's no accounting for taste, there may be a way to account for aversion. Detecting something unpleasant is among the first things that biological organisms learned to do. Thanks to a receptor that evolved half a billion years ago, certain chemical irritants — like the active ingredient in tear gas or the compound that makes up wasabi — have been annoying life on Earth since before the dinosaurs.

Some smells and sounds also seem to be intrinsically unpleasant. For instance, the annoying component in skunk smell is a sulfur-based compound. Sulfur-rich environments tend to be oxygen-poor environments, so it makes sense for creatures that need oxygen to avoid them. There may also be a biological component to why most of us can't abide the sound of fingernails on a blackboard. Some researchers suggest the fingernail noise resembles the acoustic signature of a primate warning call; others liken it to a human scream. We may be pre-programmed to register that sound as a danger signal.

The final ingredient in the annoyance recipe is that it must be of uncertain duration. A cellphone call will end eventually; you just don't know when. This uncertainty, combined with a desire that it be over soon, feeds your annoyance. You can't craft a logical plan of action for dealing with an unpleasant, unpredictable situation if you don't know how long it will last.

The good news is that taking control of an annoyance seems to alleviate the feeling — and sometimes even the source of the annoyance itself. Take a baby's wail. The annoying sound of crying prompts you to take action — you shut off the sound by changing a diaper or providing a meal. And dealing with your annoyance sometimes prevents your having to confront something worse later. If you'd ignored the crying and the wet diaper had stayed next to your baby's sensitive skin longer, you might have had to deal with diaper rash — and an even fussier baby.

Annoyances are, by definition, trivial. If the sensory assault were putting you in real danger, it would no longer be annoying; it would be a crisis. That seems to be the essence of annoyance's special role in the emotional arena: Unlike something that makes you angry or sad, in which you might be rightly justified in your feeling, an annoyance is so petty that you're expected to put up with it, even though you don't like it. Your logical mind tells you that it makes no sense for your blood to boil when the guy next to you starts smacking his gum.

If you become aware that your reaction is out of proportion with the stimulus causing it, you become at risk for what we call "terminal annoyance." This is where you become annoyed with yourself for being annoyed, and then you become annoyed with yourself for being annoyed with yourself. You've entered the annoyance spiral. It's a bad state. But there is a small positive side to the times when you start sputtering and tearing your hair out because someone sitting next to you won't stop clipping his nails: It usually makes for a good story later.

Joe Palca is a science correspondent for NPR. Flora Lichtman is the multimedia editor for NPR's "Science Friday." They are the authors of "Annoying: The Science of What Bugs Us."