The Trust Equation

Start with the behavior that's making trust difficult

A colleague once asked me whether trust could really be measured, or whether it came down to being yourself. I understand the question. You can be sincere and still leave someone wondering whether you'll follow through, understand their concern or admit that you've got something wrong.

If you want to improve a working relationship, you need to get more specific. My recommendation is to look at your own behavior first. Ask what the other person has experienced that would make their hesitation reasonable, then change something they can see.

The Trust Equation helps you do that. David Maister, Charles Green and Robert Galford introduced it in The Trusted Advisor in 2000. Their terms are Credibility, Reliability, Intimacy and Self-Orientation. In my teaching, I use Empathy and Self-Interest for the last two, as shown in the diagram.

That wording is an adaptation. The original Intimacy includes feeling safe to share something sensitive. Empathy emphasizes whether the other person feels understood. Both matter, and you should check for both when you use the model.

Treat the equation as a way to discuss a relationship. Use actual examples to choose what to improve. A score you give yourself is a prompt for that conversation; its value depends on whether the other person recognizes your description.

At a glance

• The Trust Equation adds credibility, reliability and empathy and divides the total by self-interest, so the first three build trust and self-interest reduces it.
• I teach Empathy and Self-Interest where the original authors use Intimacy and Self-Orientation, and you should check for both meanings when you use the model.
• Start with a recent incident and your own behavior, change something the other person can see, and ask them whether it has helped.

The sections below take each part of the equation in turn. The table gives a short version of each one, with a question you can ask yourself.

Make your words easier to rely on

Credibility concerns what you say. Your expertise matters, but so does how clearly you separate what you know from what you're assuming.

Before your next recommendation, check its basis. Have you read the figures yourself? Have you spoken with the people doing the work? Which part depends on a forecast? Put the relevant uncertainty in the recommendation and explain what you'd do anyway.

You can be decisive while being accurate about your knowledge. If you're asking your team to approve a project, show the assumption that would change your decision. Give someone responsibility for checking it. That makes it easier for others to challenge the work without having to challenge your integrity.

When you make an error, correct it with the people who heard the original claim. Quietly changing a document leaves them working from information you've already abandoned. Say what changed, what it affects and what you need them to do with the correction.

Keep promises you can actually keep

Reliability concerns your actions. Look at the commitments you've made in ordinary conversations: the introduction, the approval, the answer you said you'd have by Friday. Check whether you've left someone waiting.

You don't need to agree to every request. You do need to make a clear commitment when you accept one. Name the output and the date. If another priority makes that impossible, raise it early enough for the other person to make a different plan.

This is especially important when you're the CEO. Your passing agreement can become someone else's dependency. Before you finish a meeting, check which commitments people believe you've made. Put those alongside your other work so they survive the next urgent issue.

If you've missed a promise, start with the effect on the other person. Ask what they now need, make a realistic recovery commitment and meet it. An explanation may help them understand the miss. The repair still requires you to deliver.

Check whether the other person feels understood

Empathy starts with attention. Let the person explain what matters to them before you propose a solution. Summarize the concern in your own words and give them room to correct you.

Pay particular attention when their position seems unreasonable. You may be missing a constraint, a previous commitment or a consequence they expect to carry. Ask about that consequence. You can understand their position and still make a different decision.

The original equation's Intimacy adds a question about confidentiality and vulnerability. What happens when someone tells you they've made a mistake? Who hears about it next? What have you done to show that a difficult admission will get a fair response?

Amy Edmondson's 1999 field study found an association between psychological safety and learning behavior in 51 teams within one manufacturing company. That setting and observational design limit causal conclusions. Psychological safety concerns a team's shared sense that speaking up is safe; the Trust Equation helps you examine a particular relationship.

My advice is to make your response to unwelcome information useful. Ask what happened, what needs attention and what support would help. Deal with accountability on the facts. If you react to the admission before you understand the issue, you'll make the next conversation harder.

Notice when you're defending your own position

Self-interest is the denominator. The original authors use Self-Orientation to describe how much your attention centers on yourself. In practice, look for moments when protecting your reputation or preferred answer takes over the conversation.

In a pre-budget meeting years ago, a colleague challenged me directly, in front of the room, on a number I hadn't thought through carefully enough. My instinct was to defend it. Instead, I admitted that I hadn't done the thinking and asked what they would change.

That moment helped the trust between us. I'd given the colleague a reason to believe I could take a challenge seriously. The next useful contribution didn't have to come with an argument about whether I was right.

You can check this in your own meetings. When someone questions your plan, do you help them finish the point? Do you ask what evidence would change the decision? Do you give them credit when you use their idea?

Having your own interests is normal. Put a relevant conflict on the table so others can judge your recommendation with that information. If your department benefits from a decision, say so and explain how you've considered the wider business.

Use the equation to repair one relationship

Choose a relationship where working together has become harder. Write down a recent incident before you score anything. Describe what you said, what you did and how the other person responded. Leave their motives out until you've asked them.

Then consider each part of the equation. Perhaps your advice was sound but your follow-through was poor. Perhaps you delivered on time but dismissed a concern. Perhaps you understood the concern and still made the discussion about defending yourself.

If you use scores, remember that the direction differs. Low credibility, reliability or empathy deserves attention. High self-interest deserves attention too. Choosing whichever of all four scores is lowest would send you in the wrong direction when self-interest is already low.

Choose a change that fits the incident. A missed commitment calls for a dependable recovery plan. An inaccurate statement calls for a correction. A dismissed concern calls for a conversation in which you check your understanding and act on what you learn.

Ask the other person for their view before you declare the relationship repaired. They may have a different example, or a longer history than the one you selected. Give them time to see whether the change lasts.

Bring these questions to your next conversation

Try this

You can use these privately first, then ask the relevant questions directly:

• Which commitment have I left unclear or unfinished?
• What have I said with more certainty than the evidence supports?
• Which concern do I need to understand better before I offer advice?
• What happens when this person disagrees with me?
• What would they see me doing differently if this relationship improved?

When you've answered them, take these steps:

1. Choose one action you can complete this week.
2. Tell the person what you've understood and what you'll do.
3. Put a follow-up in your calendar for two weeks from now, and ask whether the change has been useful to them.

Sources

• The Trust Equation

  Trusted Advisor Associates. Undated; checked September 26, 2026. Original model published in The Trusted Advisor, 2000.

• Psychological Safety and Learning Behavior in Work Teams

  Amy Edmondson, Administrative Science Quarterly, June 1999. Original article hosted by MIT.