Trust is both and emotional and logical act. Emotionally, it is where you expose your vulnerabilities to people, but believing they will not take advantage of your openness. Logically, it is where you have assessed the probabilities of gain and loss, calculating expected utility based on hard performance data, and concluded that the person in question will behave in a predictable manner. In practice, trust is a bit of both. I trust you because I have experienced your trustworthiness and because I have faith in human nature.

We feel trust. Emotions associated with trust include companionship, friendship, love, agreement, relaxation, comfort.

There are a number of different ways we can define trust. Here are the dimensions of trust and consequent definitions.

Predictability

It is a normal part of the human condition to be constantly forecasting ahead. We build internal models of the world based both on our experiences and what others tell us, and then use these to guess what will happen next. This allows us to spot and prepare for threats and also make plans to achieve our longer-term goals.

The greatest unpredictability is at 50%; a reliable enemy can be preferable to an unpredictable friend, as at least we know where we are with them.

Value exchange

Most of what we do with other people is based around exchange, which is the basis for all businesses as well as simple relationships. At its simplest, it is exchange of goods. I will swap you two sheep for one cow. It is easy to calculate the value in such material bargaining. Things get more complex when less tangible forces come into play. A parent exchanges attention for love. A company exchanges not only pay but good working conditions for the intellectual and manual efforts of its workforce.

Value exchange works because we each value things differently. If I have a whole flock of sheep but no milk, then I can do business with a person who has a herd of cows but no clothes. This principle of reciprocity is what binds societies together.

Trust in value exchange occurs when we do not know fully whether what we are receiving is what we expect. When we buy a car, don’t want to be sold a ringer which the seller knows is faulty. When I get advice in business, I want it to be based on facts, not wild opinions.

Delayed reciprocity

Exchange is not just about an immediate swapping of cows and sheep or hugs and kisses. What makes companies and societies really work is that something is given now, but the return is paid back some time in the future. The advantage of this is that we can create a more flexible environment, where you can get what you need when you need it, rather than having to save up for it.

Trust now becomes particularly important, because otherwise we are giving something for nothing. The delay we have placed in the reciprocal arrangement adds a high level of uncertainty which we need to mitigate through trust.

What is often called the ‘golden rule’ is a simple formula for creating trust. ‘Do unto others as you would have them do unto you.’ It sets up the dynamic for my giving you something now with the hope of getting back some unspecified thing in the indeterminate future.

Exposed vulnerabilities

When we trust other people, we may not only be giving them something in hope of getting something else back in the future, we may also be exposing ourselves in a way that they can take advantage of our vulnerabilities. If I buy a car from you and I do not know a good price, you can lie to me so you get a better bargain. If I tell you in confidence about the problems I am having with work, you could use this to further your own career at my expense.

Although the threat of retribution or projected feelings of guilt can counteract your temptation to abuse my exposed vulnerabilities, if you succumb I still get hurt and may still end up with the shorter stick. For our transaction to complete successfully, I must be able to trust that such agonies will not come to pass.

So learn about trust, how it works and how to build it. If you do it well, other people will give you the earth. If you betray them, they will hunt you to the ends of the earth.