Why does Amtrak now need to have quiet cars? Why do some restaurants offer cell-phone-free seating options? Why does google index 51,500 cell phone rants?
It's not just because cell-phone ringers are obnoxious, though they are. The conversations themselves are annoying!
People often say that it's because cell-phone users talk too loudly. But I don't think this is true. I've been monitoring conversations around me in public places for the past couple of weeks -- regular live conversations as well as cell phone users -- and I don't hear much difference in amplitude. Some live conversations are softer, some are louder, and the same is true for cell phone users. The louder a conversation is, the more intrusive and annoying it is if you don't care to listen in. The thing is, though, a given cell phone conversation seems much more intrusive and annoying than an equally loud live conversation. We tend to interpret greater salience as greater amplitude, but it ain't necessarily so.
The greater salience of cell-phone conversations -- if it's true! -- could be because we're used to making allowances for others' live conversations, but cell phones are new and we aren't used to them. However, I don't think this is it. I think public cell phone users are annoying because mind-reading is hard work.
Let me explain.
Theory of mind is a term introduced by Premack and Woodruff (1978) to refer to a set of abilities that may be uniquely human: to attribute mental states such as beliefs, knowledge and emotions to self and others; to recognize that the mental states of others many differ from one's own; to use these attributed states to explain and predict behavior; and to predict how such mental states would be affected by hypothetical actions.
This is "mind reading", and it's hard to do, because there are no psionic wave transmissions involved -- it's all inference from what people say and do, how they say and do it, and prior information about them and others. It's also pretty much automatic -- if you're not autistic, you can't stop yourself from reading your companions' minds any more than you can stop yourself from noticing the color of their clothes.
But when you're only getting half the cues -- from one side of a cell phone conversation between two strangers -- you have to work a lot harder.
Recent theorizing in cognitive neuroscience suggests that humans have an evolved theory of mind module. An fMRI study by Gallagher et al. even suggests where it is in the brain:
Brain activation during the theory of mind condition of a story
task and a cartoon task showed considerable overlap, specifically in the
medial prefrontal cortex (paracingulate cortex).
So here's my hypothesis. When you're sitting in a restaurant or a railroad car, hearing one side of a cell phone conversation, you can't help yourself from trying to fill in the blanks. And after a few seconds of this, your paracingulate medial prefrontal cortex is throbbing like a stubbed toe. Or at least, it's interfering with your ability to think about other things.
[Update: a friend has observed that I myself rarely give any indication of noticing the color of anyone's clothes. Well, um, I do. Notice, that is.]
Posted by Mark Liberman at November 8, 2003 06:27 AM
