Mastering Persuasion and Credibility - Nonverbal cues that matter most

In today's era of brainrot, information overload and yap, what makes some voices rise above the rest? We can often intuitively identify whether someone is persuasive and credible, but pinpointing exactly why can be so so difficult. This article aims to unpack the factors that lead to credibility and persuasion, and I'll show you exactly how controversial figures like Andrew Tate or Donald Trump can be simultaneously polarising and incredibly persuasive.

When I was undergoing sales training, I've heard the mantra that over 90% of sales skills stems from body language and tone - your nonverbal cues rather than the exact words themselves - but what does this really mean? How can we more deeply understand the nuances of tone and body language?

Let's investigate the specific nonverbal behaviours that you can refine to enhance your persuasion and credibility, and unravel the mystery of what exactly makes up credibility and persuasion.

The Three Main Dimensions of Persuasiveness

Okay, let's break this down. There are tons of factors in your voice tone and body language that affect how persuasive you are. It's a mess trying to categorize them all - trust me, the world's leading scientists have tried. But it's possible to boil it down to three main dimensions that really impact your credibility and persuasion power:

• Pleasantness
• Potency
• Arousal

It's important to note that although there are so many dimensions that affect credibility, such as character and competence, persuasion can only be measured as one variable. For example in sales you only have one metric to measure → did the prospect buy or not?

It's also interesting to note that Pleasantness had such a limited effect on Persuasion, however had a great effect on credibility. That's really how characters like Tate or Trump seem to get away with saying whatever they want, while still being persuasive. So many people find them unpleasant, but they are still able to sway nations with a single speech.

Pleasantness Dimension

Let's talk about pleasantness, it basically measures how agreeable you sound, and it's measured by things like fluency, tempo, pitch variety, clarity and voice quality. Smooth, happy speech sounds more pleasant and more credible.

What's surprising and incredible from the research I've done is that non-fluencies (like sudden stops, ums and ahs) hurt your credibility, but don't actually hurt how people judge your character, and might even make you seem more sociable.

This piece of research finally helps understand myself and so many other people that stutter and has had discontinuities in their speech. It means that while people won't take what you're speaking about seriously (you'll be less credible), it won't take away what they think of you as a person, they won't think you're a liar or untrustworthy.

But from my experience, this makes it very explicit how you'll be knocked down the group hierarchy if you stutter or stop speech. You'll end up in a role below your skill level, but people will find you more approachable because you won't be seen as a threat.

So what boosts your competence? Quick responses. The quicker back you fire back and answer, the more competent you will seem. But the trade-off in response time is trustworthiness. Medium-response times make you seem more trustworthy. So if you're lightning fast with your response latency, people will think, "Hey, they're sharp", instead of "I'd trust them with my life". That's why expert communicators tailor their response speed to optimize for trust or competence depending on the situation.

Potency Dimension

Now, let's talk about potency. It measures how powerful, authoritative and dynamic you sound. Basically, it's a measure of how much of a leader you come across as.

Tempo is one of the biggest contributors in the potency game. You ever notice how some of the most influential speakers talk at a lightning speed, far higher than normal conversation? The key is finding the sweet spot - too slow and you sound boring, too fast and you risk sounding anxious or nerdy. However, when combined with perfect tone, it's possible to talk extremely fast in certain segments to highlight a point, without detracting from persuasiveness or credibility.

Loudness is another big factor in potency, and this one is pretty obvious - if you're speaking too quietly, you're not going to sound very dominant or dynamic. The good news is that if you've got a quiet voice, loudness is one of the easiest factors to change and work on. But don't go overboard - yelling isn't the answer either. Lose control of your volume, and you'll lose control of your audience.

Paradoxically, one of the most interesting things about potency though, is that while a high potency can make you seem more competent and dynamic, they can have a strange effect on how approachable you seem. People are often scared and anxious upon meeting a high potency person. Sometimes dialing it back and going for a softer more conversational style can make you seem more human, trustworthy and friendly. It's all about understanding the room and triggering the potency muscle strategically.

Arousal Dimension

Lastly for arousal (and no, quit it with the dirty mind, not that kind of arousal). Arousal is how much you can spike the audience's emotions. How much thrill you can inject into the audience through your speech or conversation.

While potency is all about sounding powerful and authoritative, arousal is about getting your audience fired up and injecting that emotion into their bloodstream. You can sound cool, calm and collected with a high potency, but if you can't get your audience emotional, you won't be able to persuade them. Even the most authoritative, knowledgeable person in the room is gonna struggle in sales, relationships and leadership if you can't excite your audience.

The Power of Pitch Variety

Ever wonder why some speakers just grab you? It's all about pitch variety. Here's what the research shows:

• It's strongly linked to immediacy (0.62 correlation). That means when you vary your pitch, you're subconsciously telling your audience, "Hey, I'm right here with you."
• It goes hand in hand with body language (0.56 correlation with kinesic expressiveness). When you're vocally dynamic, your body naturally follows suit.
• It makes you clearer (0.48 correlation with vocal clarity). Varying your pitch isn't just for show - it actually helps people understand you better.

💡 Action step: Practice speaking with more vocal variety. Try emphasizing different words, or experiment with raising and lowering your pitch throughout your sentences. Record yourself and listen back - you'll be surprised at the difference it makes.

Body Language: Your Silent Communicator

Your body language is screaming information about you, whether you like it or not. Here's how to understand it and make it work for you:

• Expressive gestures and facial expressions make you more approachable (0.67 correlation with immediacy)
• Relaxed body language plus expressiveness is a winning combo (0.64 correlation)
• Be careful with random movements though (0.62 correlation). A little fidgeting can make you seem real, but too much and you'll look nervous

💡 Action step: Next time you're in a conversation, focus on using purposeful gestures that match your words. Keep your body relaxed but engaged.

Tempo: Finding Your Rhythm

Your speaking speed is more important than you think:

• Fast tempo often goes with pitch variety (0.59 correlation)
• But don't forget clarity (0.38 correlation with vocal clarity)
• Find that sweet spot where you're speaking quickly enough to be engaging, but not so fast that people can't follow

💡 Action step: Try speaking about 10% faster than you usually do. But here's the trick - maintain your clarity. It's a balancing act, but master this, and you'll sound like a pro.

The Self-Adaptor (Fidgeting) Paradox

Those little nervous habits? They're not all bad:

• They're positively correlated with fluency (0.21) and pitch (0.33)
• But watch out - too much can reduce your pitch variety (-0.15 correlation)
• Some self-touching (like adjusting your glasses) might make you seem thoughtful rather than nervous

💡 Action step: Don't try to eliminate all self-adaptors. Instead, be mindful of them. Use them purposefully to create pauses or emphasize points, but don't let them dominate your presentation.

Putting It All Together

The key to mastering nonverbal communication is understanding how these different elements work together:

1. Balance your dimensions:

   • Use pleasantness to build credibility
   • Deploy potency to establish authority
   • Leverage arousal to engage emotions

2. Adapt to your context:

   • High-stakes presentations might need more potency
   • One-on-one conversations might benefit from more pleasantness
   • Sales situations often require careful balance of all three

3. Practice deliberately:

   • Record yourself speaking
   • Analyze your nonverbal patterns
   • Get feedback from trusted colleagues

What's Next?

Now that you understand the science behind nonverbal persuasion, it's time to put these insights into practice. Start small - pick one or two techniques and consciously apply them in your next conversation or presentation. Record yourself, analyze your performance, and gradually incorporate more elements as you become comfortable.

Remember, this isn't about becoming someone you're not - it's about amplifying your natural strengths and minimizing your weaknesses. As you get more comfortable with these techniques, you'll find yourself communicating with more power, authenticity, and persuasiveness than ever before.

References

1. BURGOON, J.K., BIRK, T. and PFAU, M. (1990), Nonverbal Behaviors, Persuasion, and Credibility. Human Communication Research, 17: 140-169. https://doi.org/10.1111/j.1468-2958.1990.tb00229.x