“You have a piss-poor attitude.”

It’s an old country expression–one that will not please my mother when she discovers I’ve used it. But the thing about old country expressions is they’re quite … expressive. When you hear that phrase, you have no trouble conjuring an image of the attitude in question or remembering the last time you felt that way.

This is not the attitude to win you an affectionate squeeze from your sweetie, a gold star from your boss, or really great service at your favorite restaurant.

On the other hand, it has its good points.

While positivity gurus keep preaching that the secret to success is thinking good thoughts 24/7, researchers at the University of New South Wales in Australia have found that people who have negative moods also have their positive attributes.

So sad … no?

According to the study, published in the journal Australian Science, being sad, for instance, seems to give people better information-processing strategies that make them more suited to dealing with demanding situations. People in bad moods are more cognizant of their surroundings, more critical of the information they receive. Happy people, the researchers said, are more gullible.

In one experiment, after having test subjects watch happy or sad movies, or recall positive or negative events, to help set their moods, the researchers asked them to evaluate the truth of urban legends, myths, and rumors. The happier people tended to believe whatever they were told, while the grumpier people were more discerning.

When people are happy, they exhibit more creativity, flexibility, cooperation, and ability to use mental shortcuts. When people are somewhat negative, they have better memories, demonstrate attentive, careful thinking, and pay more attention to the world around them. They’re less likely to make rash judgments based on stereotypes or prejudices, they’re more reliable eyewitnesses, and they have a better, more persuasive communication style.

Of course, the operative word is somewhat. Some sadness, some negativity is good. Too much negativity—like too much perkiness—would likely override the benefits … and make everyone else miserable.