As humans, we experience a wide range of emotions, from happiness, fear and anger, to sadness, surprise and shame. And out of this emotional repertoire, sadness lasts 240 times longer compared to other sentiments, according to new research.

A group of Belgium researchers chock this up to the fact that when we feel sad, it's often associated with a very traumatic episode, such as a death or accident. Such personal events require more time to mull it over in order to cope and fully comprehend what happened, according to researchers Philippe Verduyn and Saskia Lavrijsen of the University of Leuven in Belgium.

Described in the journal Motivation and Emotion, the duo provides the first clear evidence as to why some emotions last a lot longer than others.

Verduyn and Lavrijsen, along with colleagues, asked 233 high school students to recollect recent emotional episodes and report their duration. They also answered questions on how they deal with these various emotions. Out of a set of 27 emotions, sadness lasted the longest, whereas shame, surprise, fear, disgust, boredom, being touched, irritated or feeling relief came and went in a flash.

What's more, just because certain emotions are similar to one another doesn't mean they last for the same amount of time. For example, the researchers realized that guilt is an emotion that persists much longer than shame, while anxiety lingers longer than fear.

"Rumination is the central determinant of why some emotions last longer than others. Emotions associated with high levels of rumination will last longest," Verduyn explained in a statement.

Interestingly, while sadness is the emotion that lasts the longest - as you ruminate, or think deeply about whatever it is that made you sad - boredom is one of the shorter emotions we experience. Even though, when we're bored, time seems to drag on forever.

So whenever you're bored, sad, happy, embarrassed or afraid, just know that while these emotions may drag on or fly by, they won't last forever.