A Harvard negotiation expert walked me through a brilliant strategy for managing a personal conflict

When negotiation expert Daniel Shapiro visited the Business Insider offices, we talked about beach balls.

Shapiro is the founder and director of the Harvard International Negotiation Program, and over the course of his career he's led conflict-management initiatives in the Middle East and worked with leaders in government and business.

He's learned that appealing to rationality isn't always the best way to mend a rift; instead, both parties in a negotiation have to be willing to get in touch with the conflict's more emotional underpinnings.

In his book, "Negotiating the Nonnegotiable," he shares the strategies he's used to help people in all kinds of settings access the core emotions driving their conflicts and reach mutually beneficial resolutions.

When I sat down with Shapiro in April to discuss some of those tactics, he let me experience firsthand one of the most powerful conflict-management exercises in his arsenal: using a metaphor to describe the relationship.

Hence the beach balls.

Shapiro urged me to think about an individual I was currently in conflict with and I thought of someone in my life, who will remain nameless for privacy reasons.

"Is there a metaphor that you think could describe the nature of your relationship with [this person]?" Shapiro asked me. "When things are tense, what is it like?"

I answered tentatively: Rubber beach balls? "You can throw them at each other and the closer they get the farther apart they get, because they bounce off each other."

Shapiro lit up. "It's one thing to say, 'I have tension with [this person]; I feel sad; I love her to death and yet it's hard to connect with her. It's very different for me to understand the nature of your relationship, that you want to be close and yet too much closeness makes you deflect and bounce away from each other."

He urged me to consider what could be done to resolve this situation - without, for the moment, focusing on rationality. "Just think about those two balls. Don't think about your real relationship."

When he asked me to imagine who was throwing the balls, I stumbled again. "Um, the wind?"

"Interesting!" he said. "This is good. It feels like the wind is bringing us closer together and then further apart. Who controls the wind? It's nature - it's not you and it's not the other side."

He prompted me to imagine a fan that I could turn on when I felt like I was getting too close to this person, and off when I'm feeling distant from her.

Now it was time to apply what we'd uncovered in the metaphor process to real life.

"What would that look like to turn off the fan?" he asked me. "It might mean saying at certain points in time, 'I love you but I need a little distance today.' Or it might mean the opposite, 'I really want to connect with you more; let's do it tomorrow.' So you retake control over the fan."

I felt considerably relieved - I could potentially stop an argument between me and this person in its tracks simply by acknowledging when we were getting too close and about to "bounce" away from each other.

Another, "riskier" possibility, Shapiro said, is to do this exercise together with this person, to see if our metaphors for our relationship are similar or different. That knowledge in and of itself could help us work toward a solution.

Shapiro has used this exact exercise in more serious settings, including a study group made up of Israelis and Palestinians designed to explore the Israeli-Palestinian conflict. Some of the group members came up with the metaphorical image of Siamese twins.

"Then come all the questions," Shapiro remembered. "Does that Siamese twin have one heart or two? One brain or two? If you split the Siamese twin in half, do both sides die? Does one side live and the other side die? So you start to get at these fundamental questions once you simply move from rational argument."

In a Huffington Post article, three of the group members explain how the exercise helped them: "We began to speak more productively about the unspeakable."

Ultimately, the goal of the metaphor exercise is to do what Shapiro calls "talking about emotions without talking about emotions." Imagining myself as a beach ball floating in the wind was a whole lot easier than saying out loud that I love this person deeply but sometimes need a little distance from them and their opinions.

Without even acknowledging it, I'd taken a considerable step forward toward solving the conflict between us.