People spend a lot of time talking and thinking about how members of the opposite sex look, but very little time paying attention to how they sound. To our unconscious minds, however, voice is very important. Our genus Homo has been evolving for a couple million years. Brain evolution happens over many thousands or millions of years, but we’ve lived in civilized society for less than 1 percent of that time. That means that though we may pack our heads full of 21st century knowledge, the organ inside our skull is still a Stone-Age brain. We think of ourselves as a civilized species, but our brains are designed to meet the challenges of an earlier era. Among birds and many other animals voice seems to play a great role in meeting one of those demands — reproduction — and it seems to be similarly important in humans.
For example, women may disagree on whether they prefer dark-skinned men with beards, clean-shaven blonds, or men of any appearance sitting in the driver’s seat of a Lamborghini — but when asked to rate men they can hear but not see, women miraculously tend to agree: men with deeper voices are more attractive. Asked to guess the physical characteristics of the men whose voices they hear in such experiments, the women tend to associate low voices with men who are tall, muscular, and hairy-chested — traits commonly considered sexy. As for men, a group of scientists recently discovered they unconsciously adjust the pitch of their voices higher or lower in accordance with their assessment of where they stand on the dominance hierarchy with respect to possible competitors. In that experiment, which involved a couple hundred men in their twenties, each man was told he’d be competing with another man for a lunch date with an attractive woman in a nearby room. The competitor, it was explained, was a man in a third room.
Each contestant communicated with the woman via a digital video feed, but when he communicated with the other man, he could only hear him, and not see him. In reality, both the competitor and the women were confederates of the researchers, and followed a fixed script. Each man was asked to discuss — with both the woman and his competitor — the reasons he might be respected or admired by other men. Then, after pouring his heart out about his prowess on the basketball court, his potential for winning the Nobel Prize, or his recipe for asparagus quiche, the session was ended, and he was asked to answer some questions assessing himself, his competitor, and the woman. The subjects were then dismissed. There would, alas, be no winners anointed.
The researchers analyzed a tape recording of the male contestants’ voices, and scrutinized each man’s answers to the questionnaire. One issue the questionnaires probed was the contestant’s appraisal of his level of physical dominance as compared to that of his competitor. And they found that when the participants believed they were physically dominant compared to their competitor — that is, more powerful and aggressive — they lowered the pitch of their voices, and when they believed they were less dominant, they raised the pitch, all apparently without realizing what they were doing.
From the point of view of evolution, what’s interesting about all this is that a woman’s attraction to men with low voices is most pronounced when she is in the fertile phase of her ovulatory cycle. What’s more, not only do women’s voice preferences vary with the phases of their reproductive cycle, so do their voices — in their pitch and smoothness — and research indicates that the greater a woman’s risk of conception, the sexier men find her voice. As a result, that both women and men are especially attracted to each other’s voices during a woman’s fertile period. The obvious conclusion is that our voices act as subliminal advertisements for our sexuality. During a woman’s fertile phase, those ads flash brightly on both sides, tempting us to click the “buy” button when we are most likely to obtain not only a mate, but, for no extra (upfront) cost, also a child.
In the workplace, too, the quality of your voice can be a deciding factor in your degree of success. The pitch, timbre, volume, speed, and cadence of your voice, the speed with which you speak, and even the way you modulate pitch and loudness, are all hugely influential factors in how convincing you are, and how people judge your state of mind, and character.
Scientists have developed fascinating computer tools that allow them to determine the influence of voice alone, devoid of content. In one method they electronically scramble just enough syllables that the words cannot be deciphered. In another, they excise just the highest frequencies, which wreaks havoc with our ability to accurately identify consonants. Either way, the meaning is unintelligible while the feel of speech remains. Studies show that when people listen to such “content-free” speech, they still perceive the same impressions of the speaker and the same emotional content that they do in the unaltered speech. Why? Because as we are decoding the meaning of the utterances we call language, our minds are, in parallel, analyzing, judging, and being affected by, qualities of voice that have nothing to do with words.
In one experiment scientists created recordings of a couple dozen speakers answering the same two questions, one political, one personal: What is your opinion of college admissions designed to favor minority groups? and What would you do if you suddenly won or inherited a great sum of money? Then they created four additional versions of each answer by electronically raising and lowering the speakers’ pitch by 20 percent, and by quickening or slowing their speech rate by 30 percent. The resulting speech still sounded natural, and its acoustic properties remained within the normal range. But would the alterations affect listeners’ perceptions?
The researchers recruited dozens of volunteers to judge the speech samples. The judges each heard and rated just one version of each speaker’s voice, randomly chosen from among the original and altered recordings. Since the content of the speakers’ answers didn’t vary amongst the different versions, but the vocal qualities of their voice did, differences in the listeners’ assessments would be due to the influence of vocal qualities and not the content of the speech. The result: speakers with higher-pitched voices were judged to be less truthful, less emphatic, less potent, and more nervous than speakers with lower pitched voices. Also, slower-talking speakers were judged to be less truthful, less persuasive, and more passive than people who spoke faster. So fast-talking may be a cliché trait of a sleazy salesman, but chances are, a little speed-up will make you sound smarter and more convincing. And if two speakers utter exactly the same words, but one speaks a little faster and louder and with fewer pauses and greater variation in volume, that speaker will be judged to be more energetic, knowledgeable and intelligent.
Expressive speech, with modulation in pitch and volume, and a minimum of noticeable pauses, boosts credibility and enhances the impression of intelligence. Other studies show that, just as people signal the basic emotions through facial expression, we also do it through voice. Listeners instinctively detect that when we lower the usual pitch of our voice, we are sad, and when we raise it we are angry or fearful.
If voice makes such a huge impression, the key question becomes, to what extent can we consciously alter our voice? Consider the case of Margaret Hilda Roberts, who in 1959 was elected as a Conservative member of British parliament for north London. She had higher ambitions, but to those in her inner circle, her voice was an issue. “She had a schoolmarmish, very slightly bossy, slightly hectoring voice,” recalled Tim Bell, the mastermind of her party’s publicity campaigns. Her own publicity advisor Gordon Reese was more graphic. Her high notes, he said, were “dangerous to passing sparrows.” Proving that though her politics were fixed, her voice was pliable, Margaret Hilda Roberts took her confidants’ advice, lowered the pitch, and increased her social dominance. There is no way to measure exactly how much difference the change made, but she did pretty well for herself. After the Conservatives were defeated in 1974, Margaret Thatcher – she had married wealthy businessman Denis Thatcher in 1951 – became party leader and eventually prime minister.
Adapted from Subliminal: how your unconscious mind rules your behavior copyright 2012 by Leonard Mlodinow