Study: Overhearing conversations decreases performance
Psychologists study why our brains cannot help but eavesdrop
Published: Tuesday, September 28, 2010
Updated: Tuesday, September 28, 2010 07:09
Have you ever tried to read a book on a bus or train, only to find that you're spending more time listening in on your neighbor's phone conversation?
Lauren Emberson has. The psychology doctoral candidate at Cornell University has decided to take on an experiment that tests whether hearing half of a conversation actually causes a psychological effect in those within earshot — or whether your neighbor on the T is just that fascinating.
As it turns out, your neighbor's life is not necessarily more interesting than anyone else's.
Emberson, with a team of psychologists, found that what distracts anyone within audible range of this "halfologue" is not the conversation itself but the condition of hearing only one side of a conversation, which, according to the study, automatically draws your attention away from other brain activities and results in decreased performance of the task you are attempting to complete.
The reason? The more unpredictable a situation is, the harder the brain has to — and does — work to fill in the gaps, often involuntarily.
"Your knowledge of a situation drives what's predictable for you, and new information relative to your mental model of the world causes you to pay more attention. It's very reflexive," Emberson told the Daily.
"If you hear a loud noise behind you, everyone turns around," she continued. "But if you know you're going to hear a loud noise, you can control that reflex and keep focusing on something else. Or if you walk to work on the same route every day and know that route well, if something on it changes, you're really captured by that."
Emberson said she has overheard many bus−ride halfologues — a term coined in her lab that has since gained popularity online.
"The motivation behind this is my own personal experience of my behavior being significantly affected by overhearing other people's conversation," she said. "I needed to read on the bus as an undergrad commuting to school, and I often wouldn't be able to concentrate because people were talking on the phone nearby me."
To find out what was at play, Emberson and her team designed two experiments.
In the first, they recorded college roommates engaging in three types of speech: dialogue, in this case a full, two−sided phone conversation; halfologue, the same conversation with one of the roommate's tracks deleted; and monologue, one roommate's recap of the conversation. Then, the researchers asked volunteers to ignore the sounds they were hearing and complete two tasks, which tested for verbal and non−verbal capacity.
"They both demand a lot of attention, and they both reflect the way we use attention in our daily lives," Emberson said.
She hypothesized that the unpredictability of the halfologue impairs cognitive performance — and she was right. Volunteers succeeded less in their tasks when they overheard a halfologue but not when they overheard the more predictable, less open−ended dialogue or monologue.
And for some students who also came to the conclusion that halfologues can be more distracting, like junior John Peter Kaytrosh, the reason why is obvious.
"Not only do you sort of wonder what the conversation is about, but you also wonder how the ums, yeses, nos and sounds that people make on the phone can ever add up to a conversation," he said. "Not only that — the appearance of someone talking to someone not physically there is just disconcerting."
Junior Anna Bick had similar ideas about why the halfologue ticks her off.
"If you only hear one side of the story," Bick said, "it leaves you wondering what they're talking about."
Emberson's second experiment focused on that aura of mystery.
"There's a number of ways in which halfologues can differ," Emberson said. "They can be acoustically unpredictable, where you don't know when you're going to hear speech, and it can be informationally unpredictable, where you don't understand the conversation's full content."
To test which factor was disruptive, Emberson's team drowned out the words on the recordings, so that the next set of volunteers could just hear sound.
The result clash with what the researches had predicted: Participants who could not understand any content were not distracted at all, implying that the only reason side−conversations have any effect on us is because our brains, if given a little information, allocate attention away from other tasks to try and piece together what's missing from what they are overhearing.
For Emberson, this surprise result raises another question and another potential project: exploring how we process coversations in languages people do not understand.
"You can hear the speech, but if you don't understand it, it won't have the same effect on performance," Emberson said. "Then again, other people have said that they find language — even in languages they don't understand — distracting."
Emberson's experiment could be broadly applied to how people should be using their phones now that they know they are affecting other people, she said. Phone etiquette is already established in places like libraries for the same reasons, Bick said.
"There's nothing wrong with talking on your cell phone, but when someone answers their phone and carries out a conversation in a quiet place, like the library, then it's really annoying because not only is it one of the only noises, but it takes all your focus away," Emberson said.
But there's a chance that speaking on the phone in less intuitively disruptive situations could also have more an adverse effect than expected. A halfologue in the backseat of a car, for example, could potentially decrease a driver's cognitive ability to focus on the road, Emberson said.