Here's what you do:

First, pick out all the negative qualities in the people around you — the ones that make you want to grind your teeth or ball up your fists. Maybe your coworker consistently nags your boss for praise; perhaps your brother only calls when he's in dire straits.

Then think of what the opposite of these traits would be. In our example, maybe it would be an independent coworker, or a sibling who checks in and displays some interest in your life. Now, start acting as if these people were behaving this way.

Think it's easier said than done? Check out the following example:

Say you were to rank your coworker, Terry, in terms of how "selfish" vs. "generous" she is. You think she's selfish, so you might rank her somewhere on the scale like this:

Now you'd pause and imagine that, instead, her actions were generous. The next time she talks about a project idea, imagine that she's doing so to get your whole team's effort, not just hers, recognized.

Goulston's strategy isn't positive thinking.

It's less about thinking positively and more about acting positively.

Take the example above. When it comes to what your coworker is reallythinking or doing, you don't know. You probably never will. And it doesn't matter. What matters is that you change your actions toward that person — how you respond to what they say and do.

In other words, it matters less what you think (or daydream) about their behavior and more about how you actively respond to it in the real world.

When you start to do this consistently, here's what will happen, Goulston writes:

"The people who truly are negative may come around, at least a little. And the people who aren't truly negative — the ones you've been undefined — will respond to your new behavior with relief, gratitude, and warmth. And occasionally, you may discover that the irrational person in the relationship was actually you."

SEE ALSO: I tried the app that links you to a therapist you text during tough times, and it completely changed my view of therapy

UP NEXT: The answer to treating drug and alcohol addiction may be far simpler than you think