If there’s one aspect of interpersonal relations that’s absolutely essential in the workplace, it’s trust. Without it, the wheels of business would turn very slowly, if they turn at all.

This is true whether it’s a customer trusting that a company will fill and order and deliver it on time, an employee trusting that her boss will reward her for working long hours to meet a deadline, or one colleague trusting that another will do his share of an assigned project. And of course, the same applies in all other areas of life. No one operates in isolation.

“Trust is the social glue that holds things together. It allows us to engage in social and commercial ventures, ” points out Professor Maurice Schweitzer, one of three professors at Wharton University who recently ran a unique laboratory experiment, as described in a soon to be published paper called Promises and Lies: Restoring Violated Trust. This experiment was devised to examine what happens when trust breaks down.

“Willingness to accept vulnerability based upon positive expectations about another’s behavior,”
was the working definition of trust accepted by the Wharton researchers. They started out on the assumption that “trust is like glass” – that is, “fragile, easily broken and hard to repair.” But they soon found out that this isn’t always the case. Sometimes it is true, sometimes it isn’t. It depends.

So what makes the difference?

Prof. Schweitzer explains this with a simple example. Let’s say a friend persuades you to lend him a DVD to watch that you, in turn, had borrowed from a rental company. You agree on condition that he mail it back to the company within a week. Then you find out that this friend of yours forgot to return it to the company.

Would you trust him with another movie at some point in the future? You might, especially if your friend showed a modicum of contrition over his unfortunate oversight. All the more so, if he gave you a firm promise that he would never be so negligent again.

Now imagine the same scenario, but with one crucial difference. This time your friend tells you he sent back the DVD. A little while later, you pay him a visit and you happen to notice that very DVD on top on his TV. Would you lend your friend a movie again?

And let’s say he apologizes profusely and promises to follow through next time, would your attitude be any different? Probably not.

The results of the Wharton experiment, which involved a carefully and very cleverly designed money game, bore out in striking manner the difference between these two cases – the second case, where the offending party lies about his or her failure to carry out an obligation (or what is perceived by the other side as an obligation) and the first scenario, where he or she does not.

“Trust harmed by untrustworthy behavior can be effectively restored when individuals observe a consistent series of trustworthy actions,” wrote the Wharton academics in summarizing the findings of their experiment. Just as one swallow doesn’t make a summer, one mistake doesn’t necessarily ruin a reputation, certainly when the transgressor can consistently show that he or she has now turned over a new leaf.

On the other hand – so the experiment revealed – when a person’s trust is not only violated, but that betrayal includes deception, that trust will be difficult to restore. If you didn’t only forget to return your friend’s DVD, but on top of everything, lied about it – it’s going to be a different ball game.

And quite likely , it’s not just that your friend finds it difficult in his heart to forgive you. The point is that there has been a more powerful, more intense, shattering of the trust he had invested in you. Once shattered to smithereens , it’s all the more difficult to restore.

Let his be a powerful warning to us. When planning every step in our interpersonal relationships, we dare not lose sight of the close to inevitable consequences of our actions.