More and more of us are spending our days communicating by purely textual means, whether by email, messaging apps, or social media. But a new study shows that the traditional means of expressing yourself - simply talking - is still the most effective way of making a positive impression.

Researchers in the US have found that job candidates come across as more intelligent, thoughtful, and competent when they deliver their job pitch by speaking it, whereas the exact same language is not as compelling when it appears in printed form.

The team, from the University of Chicago Booth School of Business, asked a group of student job candidates to come up with a pitch for the company they’d most like to work for. The participants developed written pitches outlining their skills and why they thought they were the right candidate for the job. They also made a video recording of the same spiel, making their case to the camera instead of on paper.

A number of evaluators, including professional recruiters, were split into three groups, and assessed the candidates’ pitches either by reading transcripts of the pitch, listening to the audio of the video recording, or watching the full video with both audio and video enabled.

The evaluators who were able to hear the candidates’ voices - both with or without visuals - ended up rating them as more intelligent, thoughtful, and competent than those who only had access to written transcripts of the pitch, despite the fact that the language being used was identical.

The researchers suggest that since an individual’s mental capacities, including intellect, cannot be observed directly (unless you’re a mind-reader, that is), people instead look for indirect cues to help assess the intelligence of those communicating with them. The easiest and most direct way to do this, it seems, is to simply listen to people talking.

“In addition to communicating the contents of one's mind, like specific thoughts and beliefs, a person's speech conveys their fundamental capacity to think — the capacity for reasoning, thoughtfulness and intellect,” said one of the team, Nicholas Epley, in a press release.

In an interesting twist, the addition of visuals to the spoken job pitches didn’t have any beneficial effect on the evaluators’ impression of the candidates. When the evaluators watched the full video and could also see the candidates making their pitch, their assessment of the speakers’ intelligence, thoughtfulness, and competence was unchanged, suggesting that the way we string words together in speech is more important to the listener than how we look while we’re doing it.

These vocal cues “show that we are alive inside - thoughtful, active,” Epley told Matt Richtel at The New York Times. “How do we know that another person has a mind at all? The closest you ever get to the mind of another person is through their mouth.”

The research is published in Psychological Science.