MELISSA BLOCK, HOST:
Think about the times you've overheard someone on the phone. You could probably take a pretty good guess about who's on the other end, whether it's a spouse, child or colleague. We all seem to give those clues away - subtle, unconscious changes in our voices - depending on who's on the other end. Well, recently, a team of scientists wondered if people's voices change in predictable ways when they're put in positions of power. NPR's Nell Greenfieldboyce reports now on the voice of authority.
NELL GREENFIELDBOYCE, BYLINE: What does a powerful, authoritative voice sound like? Maybe like this...
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FORMER PRIME MINISTER MARGARET THATCHER: The greatest divisions this nation has ever seen were the conflicts of trade unions towards the end of a labor government.
GREENFIELDBOYCE: That's Margaret Thatcher, pretty powerful. But here's how she sounded earlier in her political career.
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THATCHER: I'm very much aware of the responsibilities and a little bit apprehensive. Who wouldn't be?
SEI JIN KO: I'd always been fascinated by Margaret Thatcher's voice because I knew that she went through voice coaching to sound more authoritative.
GREENFIELDBOYCE: Sei Jin Ko is a social psychology researcher with San Diego State University. She and a couple of colleagues recently did an experiment to see if and how people change their voices if they're put in a position of power, even without voice coaching. Over a hundred college students came into their lab to have themselves recorded, starting with a baseline of recording of their everyday voices.
KO: Having them saying just, you know, what they did in the morning when they got up.
GREENFIELDBOYCE: Then they were asked to imagine a scenario, like negotiating the purchase of a new car. Some people were told they were in a position of high power. They had inside information or lots of other offers to choose from. Meanwhile, others were told they had very little power.
KO: They really didn't have many options. The cars are selling very fast, and so the dealership's probably not going to give you a very good deal.
GREENFIELDBOYCE: Both groups were then recorded reading the exact same text out loud.
KO: It was something to the effect of, I'm glad we're meeting today to discuss this. We have a few differences that we'll need to iron out before we come to an agreement - something like that.
GREENFIELDBOYCE: Researchers took the recordings and then looked for differences between the two groups. They analyzed acoustical features like pitch, resonance and intensity. It turned out that feelings of power are reflected in people's voices.
KO: When you put them in the situation, their voices change. I think that's very, very exciting and quite powerful, shall we say - no pun intended.
GREENFIELDBOYCE: She says the voices of people with power were steadier, less sing-songy. They also were more dynamic.
KO: Because it increased in pitch and intensity variability. So they went in and out of loudness more than those in low-power.
GREENFIELDBOYCE: She couldn't play us recordings from her study for privacy reasons. But you can hear almost exactly the same thing in Margaret Thatcher's voice after she had coaching.
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THATCHER: Let me answer that very deeply because I feel very strongly about it.
GREENFIELDBOYCE: Ko says the changes Thatcher seems to have deliberately made in her voice were almost identical to the changes made automatically by the speakers given power in her study.
KO: So that was quite remarkable actually.
GREENFIELDBOYCE: These results appear in the journal Psychological Science. But the researchers didn't stop there. They did another study using the recorded voices. They wanted to know if listeners could tell who had power and who didn't. And listeners could.
KO: They do use these characteristics to make very accurate predictions of whether the speaker is the boss or not.
GREENFIELDBOYCE: Now, at NPR, we think about voices a lot. I think it's fair to say that most of us here work at sounding authoritative, powerful. Here's my very first radio piece.
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GREENFIELDBOYCE: Kevin McGowan has studied the crows living in Ithaca, New York for over 15 years. They hate his guts.
Just for fun, I sent Ko that bit of tape and asked her to run a comparison with the way I sound now.
KO: I actually have your graph right in front of me.
GREENFIELDBOYCE: She saw changes in three of the six features that seemed key in their study.
KO: You're much less sing-songy, actually a huge difference.
GREENFIELDBOYCE: Lots of things are probably at play here, like the fact that I'm 10 years older, and now I'm way more comfortable in front of a microphone. Ko says there actually hasn't been much research into how an individual's voice varies when they're put in one situation rather than another.
KO: That's what's amazing. It's practically unstudied.
GREENFIELDBOYCE: Even though as listeners we're hearing these differences all the time. Nell Greenfieldboyce, NPR News.