Inspired by Margaret Thatcher’s formidable political skills, researchers in the US sought to understand how a position of power changes a person’s voice, and how this in turn affects their relation with other people. Indeed, being in power alters the acoustic properties of the voice and those tuning in can pick up cues that tell them who’s really in charge.

Speaking with power

Credit: Christopher Witt

“Our findings suggest that whether it’s parents attempting to assert authority over unruly children, haggling between a car salesman and customer, or negotiations between heads of states, the sound of the voices involved may profoundly determine the outcome of those interactions,” says psychological scientist and lead researcher Sei Jin Ko of San Diego State University.

Margaret Thatcher had one of the most easily recognizable voices in modern history, yet she used to sound different prior to becoming elected. Under the guidance of legendary actor Laurence Olivier, Thatcher took lessons at the Royal National Theatre to help her change her pitch. Tape recordings of speeches made before and after receiving her training show a marked difference. When these are played through an electronic pitch analyser, it emerges that she achieved a reduction in pitch of 46 Hz, a figure which is almost half the average difference in pitch between male and female voices. But why did she went through all this? My guess is that it wasn’t enough for her to be a powerful person – inwardly. She had to act and assert her position through her voice; something politicians, most of all, are innately aware of.

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Ko and colleagues wanted to find out how voices vary with power and how people become influenced by these cues. In the first part of the experiment, the team recorded 161 college students while they read out loud a text. This was to determine their baseline acoustics. Then, participants were randomly assigned to play a specific role in a negotiation. Students assigned to a “high” rank were told to go into the negotiation imagining that they either had a strong alternative offer, valuable inside information, or high status in the workplace, or they were asked to recall an experience in which they had power before the negotiation started. Low-rank students, on the other hand, were told to imagine they had either a weak offer, no inside information, or low workplace status, or they were asked to recall an experience in which they lacked power.

The participants were then asked to read a second text, only this time each of them had to imagine they were leading off a negotiation with their adversary. Because the text was the same for all participants, the only thing that varied was their pitch. When the two recordings were compared, the researchers found that the voices of students assigned to high-power roles tended to go up in pitch, become more monotone (less variable in pitch), and become more variable in loudness than the voices of students assigned low-power roles.

“Amazingly, power affected our participants’ voices in almost the exact same way that Thatcher’s voice changed after her vocal training,” says Adam Galinsky of Columbia Business School.

In the second part of the experiment, a separate group of college students was asked to listen to recordings from the initial experiment and assert which of the two voices belonged to the person in charge.  Listeners ranked speakers who had been assigned to the high-rank group as more likely to engage in high-power behaviors, and they were able to categorize whether a speaker had high or low rank with considerable accuracy. The listeners shared that they believed voices higher in pitch and variable in loudness were more indicative of  high-power behaviors.

“These findings suggest that listeners are quite perceptive to these subtle variations in vocal cues and they use these cues to decide who is in charge,” says Galinsky.

Findings appeared in Psychological Science, a journal of the Association for Psychological Science.