You’re only minutes into your son’s soccer game, and the mom to your right has begun screaming at the top of her lungs.

“Go, Timmy go! Get up. Be aggressive!”

You can deal with some yelling close to your right ear, but as the game wears on, so do parents’ nerves. The team is losing. The shouting intensifies as more parents join in – to your surprise, you’re one of them. Panic fills the air. Egos are at stake. Some parents are questioning referee calls and pacing the sidelines. You’re getting angry.

If this scene seems familiar, you’re not alone. In a recent study of 340 parents attending their children’s soccer games, about half of them reported getting angry during the games. Of these angry parents, about 40 percent reacted in ways ranging from muttering to yelling comments to walking toward the field.

If you think that parents’ egos are involved, this study proves you right. University of Maryland sports psychologists Jay Goldstein and Seppo Iso-Ahola  found that control-oriented types – those parents motivated by outside influences – were most likely to see mistakes on the field as a personal affront and to report more feelings of aggression than parents who were autonomy-oriented, or self-motivated.

Wondering which type you are? Pay attention to how you behave in the car. If you have fits of road rage, you’re likely to be a control-oriented (Type-A) personality who will act up at your kid’s games. Why? Researcher Goldstein told Reuters that these Type-A individuals were more prone to erupt in anger in many situations – from being cut off in traffic to an unfavorable referee call – because their ego takes it personally.

"Taking things personally is a strong trigger for anger," he told Reuters.

Parents sometimes forget that the scene is being viewed both ways: Kids watch and hear their parents’ reactions from on the field. I once knew a 7-year-old who didn’t ask much from his parents while they watched his game: “Don’t speak. Don’t yell. Don’t give any advice. Just watch,” he said.