When a friend messes up—forgets a birthday, blows off plans or doesn’t pull their weight—it’s normal for you to feel angry and for them to feel guilty. And if they mess up again, it’s tempting to assume their guilt will increase as your temperature rises.

But that’s not how it works. In a new study published in Emotion, researchers at the University of Toronto have found that while you get madder and madder, your thoughtless friend’s level of guilt will stay roughly the same.

That’s because anger is elastic and rises incrementally, as though someone is turning dial, researchers say. In contrast, guilt acts like flipping a light switch, shooting up at the first error and then staying at the same level.

The findings have implications for managing personal relationships, says Sam Maglio, co-author of the study and professor of marketing and psychology at U of T Scarborough.

“People aren’t perfectly calibrated when they predict how someone else is going to feel,” he says. “But knowing how emotions work helps you regulate them.”

He says the gut feelings we experience after a faux pas serve a purpose—to repair our relationship. Your anger tells your friend they crossed a boundary and signals the need for a change in behavior; their guilt motivates them to apologize and do better. Both feelings exist to keep mistakes from happening again.

So what happens when your friend keeps failing?

“You might be expecting an apology because you’re overestimating their guilt,” Maglio says. “Your guess about what’s going on in their head is off and that can lead your behavior to be off.”

It’s not that we don’t feel guilty—after our first slip-up, we’ll feel guilt at more than twice the intensity of our victim’s anger. Rather, researchers propose the pattern is partly because guilt is “prosocial,” a feeling that pushes us to be co-operative and charitable. But there tends to be a limit to how intense our prosocial emotions get, which comes in handy for guilt. If we act too guilty, people may place more blame on us, increasing the social rejection we’re hardwired to avoid.

“If I’m feeling guilty, I might not apologize because I think I’m stuck with this guilt regardless of what I do, failing to realize that my apology would go a really long way for the person feeling angry,” says Maglio, who is cross-appointed to the Rotman School of Management.

Prosocial emotions also tend to blind us to the scope of a problem—we’ll donate the same amount of money to an oil spill cleanup whether there’s 100 oily ducks or 10,000. And we’ll feel about as guilty about upsetting our friend after one offense or five.

Guilt does rise in small bursts after the first mistake, but the changes are minute compared to the ramp of spikes that anger follows. Anger is a high-arousal emotion that increases easily and dissipates rapidly, and the feelings we experience from one event tend to transfer to the next.

Social closeness and apologies can dramatically how we experience anger, the study shows.

Researchers conducted seven experiments with hundreds of participants—each of whom was designated wrongdoer or victim and placed in different scenarios. In one study, participants were told it was either their best friend or a co-worker who erred. Though wrongdoers felt equally guilty regardless of who they’d wronged, when it came to best friends, victims exhibited the lowest anger of all the studies.

Another scenario had participants err five times in a row by breaking a mug and repeatedly spilling liquids on their victim’s possessions. Just before the third transgression, the victim was told the wrongdoer bought them a new mug. Anger then decreased significantly more than guilt, and each experienced less emotion after the attempted patch-up, despite the subsequent spills.

The study notes that anger often makes us want to do things that make us madder, like yell or punch something. But with guilt, we simply want the feeling to go away.

“The good news is, just as sharply as that emotion intensity went up for anger, it’s ready to go back down,” says Maglio. “Your apology goes further than you think.”