# The Trust Equation

Lexpert readers dedicated to serving clients as trusted advisors yet challenged to define “trust” in language, may find it helpful to learn that consultant Charles H. Green devised a mathematical formula for trust in business relationships:

The Trust Equation

The Trust Equation, according to Green, is “a deconstructive, analytical model of the components of trustworthiness”, i.e., it describes the one to be trusted: The Numerator of Trustworthiness combines Credibility, Reliability and Intimacy, while the Denominator is Self-Orientation (see diagram).

To be credible here, we disclose that Green’s formula dates back explicitly to 2007, not to mention implicitly since time immemorial.

### One Comment on “The Trust Equation”

1. charlesgreen
August 28, 2013 at 2:20 pm #

Hi all,

Thanks for picking up on the Trust Equation; it’s maybe the most useful contribution to the subject that I’ve been able to make.

If your readers care, the formula actually dates back to 2001, in the book The Trusted Advisor, on which I was co-author with David Maister and Robert Galford.

The term “trust equation” was in use for some years before that in a consulting firm called United Research, who in turn go it from another consulting firm called Synectics.

However, in those versions the formula was (C+I) / R , where R stood for risk. I always thought that mixed apples and oranges, because whereas credibility and intimacy were traits of a trustworthy individual, risk was either part of the situation, or of the other party, the one doing the trusting. Either way, I wanted to get the Risk part off into its own model, and leave the Trust Equation to solely describe the characteristics of trustworthiness.

Your readers may be more interested to know the results of thousands of people taking the Trust Quotient, a self-assessment tool based on the Trust Equation, and written completely by me.

Some of the more interesting results:
1. The most powerful of the four factors turns out to be Intimacy
2. Women are statistically significantly more trustworthy than men
3. Lawyers score extremely high on credibility, but are the lowest in overall scores, almost entirely because of extremely low ratings on the Intimacy factor.

All of which makes a good deal of common sense.