While people may call on higher powers to give them patience, self-control isn’t a God-given gift. Rather, it’s a human capability that, like a muscle, can be exhausted with short-term overuse and strengthened with long-term practice, according to a review article published in the journal Current Directions in Psychological Science and reported in an Association for Psychological Science statement.

Research shows that people who’ve had their self-control exhausted are more likely to react aggressively. The reason? The longer you hold yourself back from a desired activity—such as eating a treat that’s right in front of you or responding to a personal slight—the more your self-control gets depleted.

For example, in a 2009 study, researchers told participants about mean-spirited feedback that ostensibly came from a spouse or other romantic partner. Then scientists gave these participants the opportunity to retaliate by assigning their partner to perform a painful yoga pose. What happened? Participants who’d already used up their self-control assigned their partners to the yoga pose for longer.

But it turns out that practicing your self-control over a period of time makes you less likely to respond aggressively. In a study performed by Thomas F. Denson, PhD, a review coauthor, participants spent two weeks performing tasks with their non-dominant hand—right-handed people used their left hand, while lefties switched to the right—an activity requiring strict self-control to avoid switching back to the dominant hand. As part of the experiment, the participants were then insulted by a fellow student and had the opportunity to retaliate with a blast of white noise. The result? Participants were less likely to blast away at their peers than other students who had not previously practiced self-control exercises.

“For me, the most interesting findings that have come out of this is that if you give aggressive people the opportunity to improve their self-control, they’re less aggressive,” Denson said.

The reason these findings are particularly important is because research shows habitually aggressive people really do try to control themselves. Problem is, many of them find it difficult to exercise self-control. (Brain-monitoring studies found that the part of the brain linked to self-control actually works harder in aggressive people than in their less aggressive counterpoints.)

What this means for you is this: Whether you are quick-tempered or easygoing, it’s always a good idea to practice self-control. How can you develop this trait? Exercise it. For example, try to pay constant attention to maintaining good posture, or keep a plate of cookies in front of you and don’t touch any. Just remember, while these exercises are good for your long-term self-control, in the short term they can make you feel crankier and hard-pressed to control yourself.

But don’t worry, the more you challenge yourself to stay in control, the easier it becomes. In the long run, these small self-control exercises can also make it easier to deal with life’s little annoyances.