In the early 1980s, I slowly transitioned from teaching MBA classes to designing corporate training programs. Surprisingly, with this change in focus, my design partners and I soon found ourselves in, of all places, Hollywood—not the glamorous version that produces dazzling movies, but the not-so-glamorous version that produces industrial videos.

Here’s what took us to Tinsel Town. Our typical training design project consisted of following around top-performing leaders and watching how they handled challenges such as missed deadlines. From these observations, we extracted behavioral tactics (best practices) that we could teach to other leaders. The down-side being that merely talking in a training session about these valuable tactics required trainers to be gifted at describing behaviors and trainees to be talented at turning abstractions into action. Instead, we opted to demonstrate the skills on video—which took us to Hollywood.

As you might suspect, this demand to produce and direct mini-movies of leaders in action called for a huge change in the lives of training designers. My colleagues and I knew a fair amount about social science theory and practice but little about video production. Okay, we knew nothing about video production.

With time and coaching, we eventually figured out how to develop video snippets that could be used in our training but, sadly, not ones that suited everybody. Our acting team appeared a bit too white-collar. To balance out the mix, we needed to find an actor who could embody someone who was used to getting his hands dirty at work (for clients who did just that). One evening, after watching the sitcom Alf on TV, it struck me that John LaMotta, the talented actor who played the role of Alf’s neighbor Trevor Ochmonek, would be perfect for the part of a heavy-duty production worker. I called him, sent him a script, and picked him up at the airport a few weeks later to join our acting troupe as we began work on a new video project.

The next morning, I directed the first rehearsal. When it came time for John to—in his own words—“make magic,” he stormed onto the set. The situation was simple. John portrayed a gruff-looking production worker whose co-worker had failed to deliver materials to him on time—causing him problems. John’s job was to resolve the issue. To keep the scene fresh, I gave John no direction except to deliver his lines in a way that felt comfortable to him. I wanted John to calmly describe the problem in a respectful and professional way, but would he interpret the scene in that manner? Time would tell.

With the shout of “Action!” John walked onto the set, hit his mark, and delivered his opening line: “You said you’d have product to me by noon, but it never arrived. What happened?” Note: the script we had written contained no inflammatory words, insults, threats, or attacks—just a simple description of the problem followed by a diagnostic question. John delivered the correct words—no problem there—but he said them with such force and disgust that the other actor nearly melted.

“Cut!” I shouted as I leaped into the set and explained to John that he sounded furious and needed to try the scene anew but without the acrimony. Once again, I didn’t tell John how to interpret the script because I had been taught that if you over-direct, or worse still, show actors the delivery you want, they tend to mimic your performance and you lose their unique interpretation.

This time, John walked onto the set with his arms folded, slowly circled the other actor, shook his head in utter disgust, and delivered his line in a deadly whisper. It was chilling. For the third take, John poked the fellow with his massive index finger. Thump, thump, thump. It hurt just watching. Next, John sneered at the other actor so malignantly that it caused a camera operator to flinch.

For another five takes, John found five new ways to accost his coworker while I patiently waited for him to deliver an opening line that would lead to a respectful discussion. Each time, John expressed the same neutral words we had written but with new punitive body twitches, facial tics, and voice fluctuations that turned what should have been a professional, problem-solving conversation into an attack.

Finally, I gave up. I broke the rule of offering minimum direction by telling John that the fellow who had let him down was his good friend and that John was curious as to why his coworker hadn’t delivered the goods on time.

“He’s my friend, and I’m curious?” John repeated. “Yup,” I answered.

Then John delivered the lines perfectly—clearly, correctly, and full of respect.

This experience affected every scene I’ve directed from that day forward. It has also influenced how my partners and I teach how to deal with disappointments, infractions, and bad behavior. No matter how talented an actor you believe you are, if you choose to talk to others about infractions while retaining negative thoughts about how they fowled-up, your harsh judgments invariably creep into your body and facial movements. You can try to be nice, but some part of you (seemingly of its own accord) tenses up and you look upset. First a strained smile, then a contortion of the muscles in your neck, then a tapping foot, then a vein madly pulsing in your forehead—all implying a threat—all reflecting your underlying negative judgment. If you were playing poker, you’d call these revealing reactions “tells”—slight body movements or facial expressions that give away your underlying emotion (in John’s case, disappointment and anger).

John taught us that if you desire to respectfully deal with people who have let you down or behaved badly, you can’t focus solely on managing the “tells” that so readily take over your body. It’s insufficient. As soon as you fix one tell, another one replaces it. So you have to work on your underlying thinking by replacing harsh judgments with genuine curiosity. If not, no matter how nice or “professionally” you think you’re behaving, or how under control you feel, your body is emitting signals that plainly reveal your underlying disappointment, disrespect, and disgust.

So, start problem-solving discussions with sincere respect for the individual who has taken a misstep. Take care to maintain a healthy curiosity regarding the circumstances. If you assume the best—not the worst—of others, the correct body language (from a relaxed jaw to a pleasant tone) will naturally follow. In short, don’t condemn others in your heart and then try to mask your harsh judgments one “tell” at a time. You’re not a good enough actor to pull it off. John certainly wasn’t—and the same is true for the rest of us.