The findings confirmed the existence of the four boredom types Goetz and his colleagues originally proposed. But there was a surprise: a fifth boredom type the researchers hadn’t anticipated that they have dubbed “apathetic boredom.”

“We did not except this type of boredom at all,” Goetz said.

The researchers found that people experiencing apathetic boredom reported few positive emotions, but also few negative emotions, unlike reactant boredom. That’s not to say the participants enjoyed being apathetically bored — in fact, it was a far more unpleasant experience than calibrating, searching, or indifferent boredom. It was just as aversive as reactant boredom, the researchers found, but it lacked the irritability and antsy feelings of that other unpleasant boredom state. Apathetic boredom was more like depression in that participants felt flat and incapable of emotion.

“Apathetic boredom seems to be similar to learned helplessness or depression,” Goetz said. Learned helplessness is a depression-like state that occurs when people or animals are so beaten down by circumstances that they stop taking opportunities to improve their condition.