There is a corporate event in Vienna that I think about more than I probably should. It was a mid-sized conference, maybe two hundred people, in one of those hotel ballrooms where the carpet pattern alone could induce a migraine. I was doing a mentalism piece, and at the moment of the reveal, something happened that changed how I think about audience reactions forever.
The person I was working with — a senior manager from the company hosting the event — did not just react. She erupted. Her hands went to her face, her jaw dropped, she took two physical steps backward, and she made a sound that was somewhere between a laugh and a scream. It was completely genuine, completely unfiltered, completely human.
And here is the part that mattered: the entire room followed her. Not intellectually. Not because they understood what had happened. Many of them were seated at angles where they could barely see the details of the effect. But they saw her reaction, and that reaction traveled through the room like a wave. People who had been checking their phones looked up. People who had been whispering to their neighbors went silent. Within two seconds, the entire room was in a state of heightened engagement, not because of what I had done, but because of what she had felt.
That night, alone in my hotel room, I kept replaying the moment. Not the trick. Not the method. The wave. The way one person’s genuine emotion had become two hundred people’s shared experience.
The Science of Catching Feelings
When I later read Ken Weber’s Maximum Entertainment, I found a framework for understanding what I had witnessed. Weber puts it simply: people react to people. We laugh when others laugh. We cry communally. We feel the embarrassment of a stranger’s awkward moment as if it were our own. Emotions are not private experiences that happen inside individual skulls. They are social phenomena that spread through groups the way a yawn spreads through a meeting room.
This is not a metaphor. Neuroscience has a name for it: emotional contagion. The basic mechanism is straightforward. When we observe someone experiencing an emotion, our brains partially simulate that emotion internally. Mirror neurons fire. Facial muscles subtly mimic the expression we are seeing. Our physiology begins to align with the other person’s state. We do not decide to feel what they feel. We just do.
Anyone who has ever been in a cinema knows this intuitively. A horror film watched alone in your apartment is mildly scary. The same film watched in a packed theater, where the person next to you is gripping the armrest and the woman three rows ahead just shrieked, is terrifying. The film has not changed. The content has not changed. What has changed is the social context — the emotional field generated by the collective response of other humans.
Stand-up comedians know this better than anyone. There is a reason comedy clubs pack people close together. There is a reason comedians prefer a sold-out small room to a half-empty large one. It is not vanity. It is physics — the physics of emotional contagion. Laughter is literally contagious. The sound of other people laughing triggers laughter in us, often before we even process why something was funny. Sitcom laugh tracks work on this principle. We know the laughter is fake. We laugh anyway.
Why This Matters for Performers
Once you understand emotional contagion, your entire approach to performance shifts. Because you realize something that is both liberating and terrifying: your job is not to create a reaction in every single person in the room individually. That is impossible. In a room of two hundred, you cannot personally connect with two hundred people. You cannot ensure that each individual has a clear sightline, understands the context, and is emotionally primed for the moment.
But you do not need to. You need to create a genuine, visible, audible reaction in a few key people — and let contagion do the rest.
This reframes everything. It reframes how you select volunteers. It reframes where you position them. It reframes how you design your reveals. It reframes how you handle the moment after the magic happens.
Think about it from the engineering perspective I bring from consulting. If you are trying to spread an idea through an organization, you do not try to convince every employee individually. You identify the influencers, the connectors, the people whose reactions carry weight with others. You create a powerful experience for those key nodes, and then you let the network effect amplify it.
Audiences work the same way. Every audience has natural amplifiers — people who react expressively, who laugh loudly, who gasp audibly, who are physically demonstrative. These are not hecklers or attention-seekers. They are simply people whose emotional responses are more visible to others. And when those people react, the room follows.
The Architecture of Contagion
So how do you actually use this? Here is what I have learned, through both study and a fair amount of trial and error.
First, you position your key reactors where they can be seen. Weber makes this point emphatically: one of the biggest mistakes performers make is not positioning the spectator where the rest of the audience can see and hear their reaction. If the person reacting is facing away from the audience, or is hidden behind a table, or is seated in such a way that only the first three rows can see their face, you have built a firewall around the contagion. The reaction happens, but it does not spread.
I learned this lesson the hard way during a show in Salzburg. I had a volunteer seated — seated, which was my first mistake — at a small table to my left. When the reveal happened, her reaction was extraordinary. I know this because I was standing right next to her. But the audience’s response was muted. Later, watching the recording, I understood why: from the audience’s perspective, all they could see was the back of her head. The most powerful reaction of the evening had been invisible to the very people who needed to see it.
Second, you give the reaction room to breathe. This is the principle Weber calls allowing reactions to fully develop. The instinct, especially when you are nervous or running on adrenaline, is to keep moving. The reveal happens, someone gasps, and you immediately start talking again, setting up the next phase. But when you do that, you step on the contagion. The wave never has time to travel.
The discipline is to pause. To stand in the silence after the reveal. To let the first person’s reaction ripple outward. To let the laughter build rather than peak and immediately recede. This requires confidence, because silence feels dangerous on stage. Your internal monologue screams that you need to fill the space, that silence means something has gone wrong. But in reality, those three or four seconds of silence after a strong reveal are where the emotional contagion does its work. The gasp becomes laughter becomes applause becomes a shared experience that bonds the room together.
Third, you react to the reaction. This is subtle but important. When a volunteer has a strong response, and you visibly enjoy it — when you smile genuinely, when your own body language communicates delight at their delight — you amplify the contagion further. You become a mirror of the mirror. The audience sees the volunteer react, and then they see you react to the volunteer, and both signals reinforce the emotional message: something extraordinary just happened.
I have noticed that the performers I admire most are masters of this moment. They do not rush past it. They savor it. They let the audience see that even the person who caused the magic is moved by the human response to it.
The Dark Side of Contagion
There is a flip side to emotional contagion that needs to be acknowledged, because it bites performers who are not aware of it.
If positive emotions spread, so do negative ones. Boredom is contagious. Discomfort is contagious. The audience member who is visibly not having a good time — the person with crossed arms and a stone face in the second row — is radiating a signal that others pick up on. The volunteer who looks confused or uncomfortable on stage is not just having a bad personal experience. They are broadcasting that discomfort to the entire room, and the room absorbs it.
This is why how you treat your volunteers matters so much. Not just for the volunteer’s sake, though that matters enormously. But because the volunteer is a transmitter. If they are embarrassed, the room feels embarrassed. If they are tense, the room tenses. If they look like they wish they were anywhere else, every person in the audience subtly identifies with that feeling, because they could have been the one called up.
I have seen performers get cheap laughs at a volunteer’s expense and not understand why the room’s energy dropped immediately afterward. The laughter was real, but it was laughter laced with anxiety. The contagion was: this performer might embarrass me too. And that is not a feeling that makes people open to wonder.
Engineering the Positive Wave
The practical takeaway from all of this is that you are not just performing for the person in front of you. You are performing for the room, through the person in front of you. Every volunteer, every interaction, every reveal is a broadcast tower. The signal it sends depends on the quality of the experience you create.
I have started thinking about my shows in terms of emotional broadcast moments. Where in the set are the points where one person’s reaction will be visible and audible to the room? How can I position those moments so the contagion has maximum reach? How do I ensure the people having those reactions are comfortable, delighted, and genuinely surprised rather than stressed or confused?
At a keynote I did in Linz last year, I deliberately structured my mentalism segment so that the key reveal happened with the participant standing, facing the audience, with a handheld microphone near enough to capture any verbal reaction. When the moment landed, her whispered “How is that possible?” was picked up by the microphone and carried through the room’s speakers. Two hundred people heard the wonder in her voice at the same time. The contagion was instant and total.
Was I lucky that she reacted well? Partly. But I had also spent several minutes building rapport with her, making her comfortable, making it clear that she was a valued part of the experience rather than a prop being used. Her genuine comfort was the foundation of her genuine reaction, and her genuine reaction was the foundation of the room’s collective experience.
The Consultant’s Lens
I keep coming back to the parallel with my work in strategy and innovation. In that world, we talk about culture change, about how organizations adopt new behaviors. The research consistently shows that culture does not change through memos or policy documents. It changes through visible, emotional, lived experiences that spread from person to person. One leader who models the new behavior authentically, in a way that others can see and feel, does more for culture change than a hundred PowerPoint slides.
Audiences work the same way. You cannot tell two hundred people to be astonished. You cannot instruct them to feel wonder. But you can create the conditions where one person’s genuine astonishment becomes the room’s shared emotional experience. And that, more than any technique or method, is the real craft of live performance.
The magic is the catalyst. The human reaction is the show. And the contagion between humans — that invisible, unstoppable spreading of feeling from one person to the next — is the medium through which a room full of strangers becomes, for a few minutes, a single organism having a shared experience.
That is what I saw in Vienna that night. Not a trick. Not a method. A wave. And I have been chasing it ever since.