"Slow down." It's the most common advice speakers receive. Take your time. Let your words breathe. Give the audience a chance to absorb what you're saying.
The problem is, this advice might be making you less persuasive.
Decades of conventional wisdom tell us that deliberate, measured speech conveys authority and thoughtfulness. Fast talkers, we're told, seem nervous, pushy, or like they're trying to slip something past us. The used car salesman talks fast for a reason, right?
Wrong. The research tells a different story.
The Research
In 2021, researchers Joshua Guyer, Richard Petty, and colleagues published a comprehensive analysis of how vocal characteristics affect persuasion. Their paper, published in the Journal of Nonverbal Behavior, examined how paralinguistic features, including speech rate, pitch, and loudness, influence perceived confidence and ultimately persuasive effectiveness.
One of their clearest findings: when speakers were instructed to sound confident, they naturally spoke faster. And listeners noticed. There was a linear increase in ratings of speaker confidence alongside increases in speech rate. Faster speech consistently led to higher confidence perceptions across multiple studies.
But the researchers went further than just measuring perceptions. They applied the Elaboration Likelihood Model to understand how this works. When listeners are not thinking deeply about the message, fast speech acts as a simple cue: "This person sounds confident, so I'll trust them." When listeners are engaged and thinking carefully, confident-sounding speech can bias their thinking in a favorable direction.
The research identified a cluster of vocal markers that signal confidence: lower pitch, faster rate, greater loudness, and falling rather than rising intonation. Of these, speech rate is the easiest to consciously control.
Why This Happens
The Guyer research shows that vocal confidence operates through multiple psychological pathways depending on how engaged your listeners are.
When your audience is not thinking deeply, perhaps during a routine meeting or a low-stakes conversation, fast speech works as a simple peripheral cue. Listeners unconsciously think: "This person sounds confident, so they probably know what they're talking about." The confidence signal shortcuts their evaluation.
When your audience is actively engaged and thinking carefully, fast speech still helps, but through a different mechanism. It biases their thoughts in a favorable direction. The same arguments sound more compelling coming from a voice that projects certainty.
This doesn't mean you should speak as fast as physically possible. The key insight is that the conventional advice to "slow down" may be wrong. Many speakers already speak more slowly than optimal for perceived confidence, and slowing down further only makes things worse.
Practical Applications
1. Stop Artificially Slowing Your Natural Pace
If you tend to speak at a moderate to fast clip when you're comfortable and confident, that's probably working in your favor. The goal is not to achieve some idealized slow delivery. It's to speak at the pace where you are fluent and natural. Don't fight your instincts.
2. Use Speed Strategically
Faster delivery works especially well when you want to establish credibility and expertise. During the parts of your message where you need the audience to trust your knowledge, a brisker pace signals that you know what you're talking about. Save the slower moments for emotional emphasis or when introducing complex new concepts.
3. Practice Until You Can Go Fast Without Stumbling
The persuasive advantage comes from fast AND fluent speech. If speaking quickly causes you to trip over words or lose your place, that undermines the competence signal. Use impromptu practice to rehearse until you can deliver at a faster pace while staying smooth. The goal is confident velocity, not rushed chaos.
4. Match Speed to Context
While faster speech wins in persuasion contexts like sales presentations and pitches, remember that different situations have different goals. When teaching complex material or giving instructions, clarity matters more than impressiveness. The research applies specifically to contexts where your goal is to persuade.
The Bottom Line
The advice to "slow down" is one of public speaking's most persistent myths. Research shows that faster speakers are perceived as more knowledgeable and more persuasive. Speed signals competence. Instead of artificially throttling your pace, focus on becoming fluent enough to speak quickly without stumbling. Your natural pace might already be closer to optimal than you think.
Put This Into Practice
Knowing that faster speech signals competence is useful. Knowing your actual speaking pace is better.
Track your pace, because speed is a signal you can control.