We can think of it as a chicken-and-egg thing: You have feelings—anger, anxiety, jealousy, resentment, whatever—which then stir up all kinds of thoughts. Or, no, you start thinking about what someone did, and that stirs up anger, anxiety, etc. There are both camps; many people I meet in my office tend to see emotions as the driver—I do what I do based on how I feel.

I’m in the thought camp, but it’s not just everyday thoughts. It’s something more solid, more core—faulty beliefs, assumptions, and expectations. These are what precede and then fuel the subsequent emotion. Here are 4 of the most common belief drivers:

1. I should/shouldn’t do______.

Beliefs in the form of shoulds are about rules, usually inherited from others—parents or authority figures. If you break the rule, and don’t do the “should,” you likely feel guilty and/or ashamed.

2. They should/shouldn’t do_________.

It’s easy to transplant your shoulds onto others, expecting them to do what you think you should do. My boyfriend should listen and not be critical, or my boss should appreciate my working overtime. When others violate these beliefs, it stirs anger, resentment, disappointment, surprise, or some combination of them all.

3. It’s supposed to be_______.

The vacation is supposed to be fun or relaxing. The promotion is supposed to be challenging. This sounds like shoulds, but it is more about expectations, situations, and events than about people. If the expectations are not met—say, it rains the entire vacation or the promotion isn’t a challenge but a headache—you feel angry, disappointed, and depressed.

4. This is not fair; I don’t deserve______.

I don’t deserve to be criticized by my boyfriend when I’ve done nothing wrong. It’s not fair that I didn’t get that promotion after putting in all those overtime hours. Disappointment, resentment, anger, and anxiety take over.

The belief becomes the story.

Your belief now becomes the foundation for a more elaborate story. It may be about the past: My parents always favored my brother; it’s not fair; they shouldn’t have done that. Memories pile on, validating the story and fueling anger and resentment.

Or the story may be about you and your self-image: My parents favored my brother and didn’t love me because I’m unlovable; I’m a loser, and no one will ever love me; I never get a break. You now unconsciously look for evidence to support your perspective.

Or the story may be about society or the larger world: People are basically selfish and can’t be trusted, or life is out to screw me over.

Whatever your story may be, it becomes not only something you continually tell yourself but also a lens that filters everything you see, shapes the evidence you find, and sets a baseline for your emotions and attitude toward life.

So, if feelings come from beliefs, changing how you feel begins with changing the beliefs that drive them. How do you do that?

Step back from your feelings and ask which beliefs are driving your reaction.

You’re angry at your brother or feeling guilty: What’s behind this feeling? What assumptions or expectations am I making—the shoulds, the supposed tos, the not-fairs? Stepping back to reflect not only helps you get out of your emotional brain and into your rational one, but with practice you’ll diagnose the source more quickly.

What is the story you’re telling yourself?

You feel that your parents always favored your brother, or that you’ve always done a lot to support him over the years but have received little appreciation in return. You feel guilty because you never got back to your friend about coming for dinner, and you don’t follow through much.

Question the evidence.

This is where you become your own advocate or attorney. Your brother has appreciated your support and has tried to show it through actions a few times in the past. Yes, you feel guilty right now, but it is not the bigger pattern you imagine. You’re stressed and hard on yourself, but you’re generally good at following through.

Experiment with changing the story.

This is what good therapy or even a good friend can do: give you a different lens or a new perspective. Your parents weren’t favoring your sister but were simply giving her extra attention because of her disabilities. Your brother is struggling with his own issues right now, and you need to cut him some grace. You do tend to be self-critical when stressed, particularly about relationships. You need to work on your stress and self-criticism, rather than scolding yourself.

The key word here is experiment. You don’t want to create another should. Instead, adopt an attitude of curiosity. Wonder how your thoughts always drift to the same old places, assumptions, and stories. These are what shape your view of yourself, your relationships, your problems, and your view of the world.

You have the power to change how you feel. It’s just a matter of changing your mind.

To find a therapist, visit the Psychology Today Therapy Directory.