Who knew boredom could be so interesting? But it's not just being bored; it's what kind of boredom you are experiencing that has researchers intrigued.

According to an article published in the journal Motivation and Emotion, there are five types of boredom—which is one more than the research team expected to identify. The boredom varieties range from a calm and pleasant experience to something more like depression.

The research team, led by Thomas Goetz of the University of Konstanz and the Thurgau University of Teacher Education in Konstanz, Germany, collected real-time data from university and high-school students multiple times a day over a two-week period. They found that boredom is not only widespread—every student in the study experienced some level of boredom—but it's also more common than other emotions. "Boredom is the most often and most intense emotion experienced by students," wrote Goetz in an email, "much more intense than enjoyment, anxiety or anger."

Students reported if they were bored, answered questions about their positive or negative feelings, and rated how calm or fidgety they felt. From these reports the researchers identified five different types of boredom. They also found that tedium is personal. "People tend to experience specific types of boredom," said Goetz, which could mean that boredom is linked to your personality.

So, which type of boredom do you experience?

Indifferent boredom: This is a pleasant form of boredom, said Goetz, giving as an example a student who has had a really long day. "You go to a class, you are tired, and the class is boring. However, the boredom is experienced as rather relaxing and even positive. It is still boredom, but you like being bored." Another example? Zoning out on the couch in front of a marathon of trashy reality TV.

Calibrating boredom: Do you let your thoughts wander? If you are open to new ideas but don't feel any motivation to actually get up and do something, that's calibrating boredom. "It is like daydreaming," said Goetz, "but not actively searching for new actions."

Searching boredom: If you have ever responded to the question "why did you do it?" with "because I was bored," you have possibly experienced searching boredom. People who experience searching boredom are highly motivated to find a more interesting activity. This type of boredom can lead to innocuous behavior like texting a friend, or may prompt violent or risky actions, explained Goetz. "However, searching boredom can also result in highly creative and positive actions," he said. "Thus, it is a big chance—it leads to actions."

Reactant boredom: Trapped in a boring lecture or never-ending meeting? You may be experiencing reactant boredom. When you can't change your circumstances—get up and leave the classroom or conference room—your boredom may be accompanied by restlessness and aggression, along with the desire to do something else. "You are bored, you can't leave the situations, and this goes in line with feelings of aggression," said Goetz.

Apathetic boredom: This type of boredom was a surprise to the researchers. The other types were first identified in a 2006 study that Goetz participated in, but apathetic boredom—a very unpleasant form of boredom accompanied by a lack of motivation—emerged from this recent research. It seems to be similar to depression, and it may have more negative consequences than other types.

"Apathetic boredom can be assumed to be detrimental for personal psychological health," Goetz said.

Are there more ways to be bored out there? "I don't think that there are further types of boredom," said Goetz, "but let's see."