Your Brain Never Stops Playing the Confidence Game

Source: Wikipedia

Business management and sales training often includes sessions on how to say what you want to say – the tone-of-voice packaging of the message. This is partly intuitive -- the pitch and weight of one’s tone influences the listener; soft to cajole, loud to command, so forth. But regardless of tone, clearly some people’s voices carry more influence than others. We seem to be equipped with a way to detect the level of confidence embedded in others’ voices, and even a loud tone—if lacking the confidence intangible—isn’t likely to cause much more than irritation.

New research puts a finer point on the confidence issue by tracking changes in listeners’ brain activity when hearing someone make a statement. The results suggest that the brain detects and assesses confidence in another’s voice in as little as 0.2 seconds.

Researchers from McGill University in Montreal, Canada outfitted the heads of a group of volunteers with 64 electrodes while monitoring electroencephalograms (EEGs) as they listened to a series of statements. The statements were recorded by actors told to come across as either confident, nearly confident, unconfident or neutral.

The researchers identified positive peaks in brain activity in all of the volunteers’ brains after playing about 200 milliseconds of the voice recordings, regardless of confidence level, but confident speech sparked significantly higher peaks of brain activity than unconfident speech. Nearly-confident speech triggered additional brain activity after another 130 milliseconds elapsed, suggesting that it required slightly more time for decoding.

What these results indicate is that confident speech grabs the most attention, and demands the highest level of processing speed, from the brains of listeners. And the effect is almost instantaneous; our brains are able to determine whose voice merits the most consideration before we've even considered what’s being said. "We found that when a speaker is very confident about something, this can be assessed at a very early stage," commented study co-author Xiaoming Jiang.

To put this in context, it’s correct to say that your brain figures out whether someone’s voice is worth hearing faster than a blink of an eye (which requires between 300-400 milliseconds).

It’s not entirely clear from the study results what makes certain speech sound more confident or “nearly confident”, because acoustically the two sound similar. But unconfident speech consistently came across with a higher pitch and was slower than other speech, and was also characterized by pitch rising at the end of the statement (the infamous “uptalk” effect).

These results jibe well with results from previous research showing that the human brain also only needs 200 milliseconds to decipher facial expressions.

The latest study was published in the journal Cortex.

You can find David DiSalvo on Twitter @neuronarrative and at his website daviddisalvo.org.