Persuasive Speech: How The Way We Talk Sways People

By Alejandro Adrian LeMon, PhD News Editor on May 16, 2011

A new study finds how different speech characteristics persuade people to participate in telephonic surveys. The results also extend to many other scenarios, from car sales to persuading voters and getting people to agree with you.

Jose Benki, research investigator at the U-M Institute for Social Research (ISR) and speech scientist with a focus on psychology language, found that interviewers who speak moderately quick, at about 3.5 words/second, had more success at getting participants to agree than interviewers who talk very quickly or too slowly.

For the study, scientists used recorded 1,380 introductory calls by 100 male and female telephone interviewers at the U-M ISR. The interviewers' speech rates, fluency, and pitch, were analyzed and correlated with their success in persuading individuals to participate in the telephonic survey.

It was previously assumed that people who talk quickly are seen as aggressive or “go-getters”, and people who talk slowly are perceived as slow or undecisive, but the results from the study showed quite the opposite.

The study also hypothesized that interviewers who are more animated, with frequent pitch variation in their voices, would have more success engaging participants.

Lead researcher Benski discovered little pitch variation by interviewers with the highest success rates. According to these findings, Benski suggests that while pitch variation can be helpful for some people, for others excessive pitch variation comes across as superficial and robotic. Thus, it appears to backfire and turn participants off.

The study also found that men with deep voices had more success than their high-pitched male counterparts. But there was no strong evidence that pitch differences were a factor for female interviewers.

During the last part of the experiment, the researchers examined speech pausing. The study revealed that interviewers who pause more frequently have more success than even those who are highly fluent.

According to Benki, people naturally pause 4 or 5 times a minute when they speak. These pauses can be filled or silent, and this rate sounds the most natural during a conversation. Interviewers that make few or no pauses sound scripted, and generally have poorer success rates in engaging participants.

Individuals that pause excessively are seen as slow or have some sort of a speech impediment.

However, the most striking finding of the study revealed that even the most disfluent interviewers had higher rates of success than those with perfect speech fluency.

Source: University of Michigan via Science Daily