A common complaint among my patients is that they can't -- or maybe just won't -- trust people. This difficulty trusting others typically stems from past betrayals. As a result of these past hurts, my patients conclude, "If I trust someone, they will hurt me. If I don't want to get hurt then I should never trust anyone."
Of course, this too has painful consequences. It makes for a very lonely existence. Refusing to trust anyone simply isn't conducive to living a happy life. My patients typically realize this; they seek my help in learning how they can trust without getting hurt.
The first thing I tell people is that trust ALWAYS involves some level of risk. There is no way to guarantee that a person won't hurt you once you decide to trust them. There are, however, ways to decrease the risk associated with trusting others -- risk management strategies, if you will.
The most important rule when learning to trust is this: only trust a person as much as you know him. In my opinion, the best predictor of an individual's future behavior is his past behavior. If a person behaves a particular way in a given situation he is likely to behave that way in similar situations in the future (unless something significant occurs to change things). Taking the time to get to know a person, to spend time with him and observe his behaviors in a variety of situations, improves your ability to predict how he is likely to act in the future. Trust is a future oriented construct; when you trust someone, you are essentially betting that the person will (future tense) fulfill an agreed upon commitment. Being able to make predictions about a person's likely future behaviors makes trusting that person a lot less risky.
Janina Davison-Forder (themoraltimes.com/?p=2820) makes a very good point about trusting that will serve as Rule #2: trust people to be who they are, not who we want them to be. If, for example, you have a friend who is habitually late everywhere she goes it is foolish to trust that she will be on time to a particular event, no matter how important the occasion. If your brother is terrible with money it is unwise to loan him money and trust him to repay you in a timely manner, even if he swears he will. People can only be who they are; trust them to be exactly that.
A third point to remember (though not necessarily a "rule") is that trust is not an "all or nothing" thing. There are different levels and degrees of trust. It is also possible to trust people in certain areas but not in others. You don't, for example, have to trust someone to take a bullet for you in a gunfight in order to trust him to feed your dog while you're out of town.
Another important principle about trust is this: healthy trust develops gradually, over time. This goes back to Rule #1 (trust someone only as much as you know them). It takes time to get to know a person. Likewise, it takes time to determine how trustworthy a person is. Now there is no standard for how long you should know someone before trusting him. You can, however, take a gradual approach without following a specific timetable. Start out determining if you can trust the person with small things. Does he call you back within a reasonable time when you leave a message? Does she show up on time when you've agreed to meet? Does he refrain from sharing with others information you have told him in confidence? Does she offer positive feedback (versus criticizing everything you do)? Does she self-disclose at around the same level that you do?
The final piece of guidance I offer to help with learning to trust is this: work on strengthening yourself emotionally and psychologically. Earlier I talked about the fear of trusting others as being embedded in the fear of being hurt or betrayed. Implicit in this fear is that being hurt is overwhelming and you simply can't handle it. If your work on building your inner resources you learn to take care of your own emotional needs (instead of depending on someone else to fulfill them). When you are able to do this you learn to trust yourself. This means trusting that you will be ok, even if someone hurts you or betrays your trust.