Blame it on the company you keep

Think you’re sober? You might need to step away from your group to accurately gauge that: People tend to underestimate how drunk they are when they are surrounded by other impaired people, new research from the U.K. suggests.

After interviewing about 400 people outside pubs about their perceived level of intoxication, the researchers found that people were more likely to rate themselves as less drunk than they really were when they were around others who were inebriated, too.

On average, they perceived themselves as only moderately drunk, even though breath tests indicated they exceeded the limit for drunk driving.

Signs of intoxication—like slurring, balance issues, confusion, or talking loudly—are more noticeable if you’re the only one in the group experiencing them, says lead researcher Simon Moore, Ph.D.

But when those around you are acting in a similar state, you might not pick up on the behaviors in yourself as readily.

Sticking close to a sober buddy or your designated driver may be able to help you gauge your drunkenness, he says.

But it’s really not something you can accurately determine by feel alone. So your best bet is to set a limit of drinks before you go out, and make sure you stick to it—no matter how much those around you are drinking.

That will prevent you from agreeing to another round of shots when you’re already a couple drinks in and your judgment isn’t as sound.