We tend to think of boredom as a price we pay for being intelligent and self-aware. Clearly we aren't the only species to suffer. Yet, given how common this emotion is in daily life, it's surprising how little attention it has received. Now that is changing and, as interest increases, researchers are addressing some fascinating questions. What exactly is boredom? Why are some people more prone to it than others? What is it for? Is it a good or bad thing? And what can we do to resist it when it strikes? Some of the answers are hotly contested - boredom, it turns out, is really rather stimulating.

Like other emotions, boredom didn't just arise spontaneously when humans came on the scene. Many creatures, including mammals, birds and even some reptiles, seem to have a version of it, suggesting that there is some kind of survival advantage to feeling bored. The most plausible explanation is that it serves as a motivator. Boredom could have evolved as a kind of kick up the backside, suggests animal psychologist Francoise Wemelsfelder, at Scotland's Rural College, in Edinburgh.

"If a wild animal has done nothing for a while there is a lot of evidence that it will go out to look for things to do, and there is definitely survival value in that," she says. It will know, for example, that an escape route is blocked, because it has explored its territory.

Where boredom stops being useful and starts becoming a problem is when the ability to explore is thwarted.

"All animals want and need to engage with the environment," says Wemelsfelder. That's why they get bored if you put them in a plain wire cage and, if left there, may end up exhibiting strange behaviours such as pacing in a figure of eight or pulling out their own feathers. "Even if they don't sit there thinking, 'Damn I'm bored', I still think they suffer," she says.

Human boredom may be more complex, but there are parallels. In his book, , Peter Toohey, a professor at the University of Calgary, Canada, compares it to disgust - an emotion that motivates us to avoid certain situations.

"If disgust protects humans from infection, boredom may protect them from 'infectious' social situations," he suggests. And, as with other animals, boredom seems to occur when we feel physically or mentally trapped. One study, for example, found that people given no choice but to participate in a dull activity in the lab reported that time dragged, and rated the task as more boring than those who had chosen to participate.

We all know how it feels - it's impossible to concentrate, time stretches out, a fog descends and all the things you could do seem equally unlikely to make you feel better. But defining boredom so that it can be studied in the lab has proved difficult. For a start, it isn't simply about aversion or feeling trapped, but can include a lot of other mental states, such as frustration, apathy, depression, indifference and surfeit. There isn't even agreement over whether boredom is always a low-energy, flat kind of emotion or whether feeling agitated and restless counts as boredom, too.

Thomas Goetz, of the University of Konstanz, in Germany, suspects it can be all of these things. By asking people about their experiences of boredom, he and his team have recently identified five types: indifferent, calibrating, searching, reactant and apathetic (see sidebar on page 24). These can be plotted on two axes - one running left to right, which measures low to high arousal, and the other from top to bottom, which measures how positive or negative the feeling is. Intriguingly, Goetz has found that while people experience all kinds of boredom, and might flit from one to another in a given situation, they tend to specialise in one. However, it remains to be seen whether there are any character traits that predict the kind of boredom each of us might be prone to.

Of the five types, the most damaging is "reactant" boredom, with its explosive combination of high arousal and negative emotion, which adds up to a restless, angry person in need of an outlet. The most useful is what Goetz calls indifferent boredom: someone isn't engaged in anything satisfying but neither are they particularly fed up, and actually feel relaxed and calm. He believes that in the right circumstance this type of boredom can be a positive experience.

"If you have a hard day and in the evening you go to a class, it might be boring but it's OK to be bored because you had a stressful day. Time feels like it's standing still, but it's not too bad," he says.

Psychologist Sandi Mann, of the University of Central Lancashire, in Britain, goes further. She believes this positive kind of boredom and, to some extent all kinds, can be good for us.

"All emotions are there for a reason, including boredom," she says. As well as motivating us to do something more interesting, Mann has found that being bored makes us more creative. "We're all afraid of being bored but, in actual fact, it can open our minds, it can lead to all kinds of amazing things."

In experiments published last year, Mann found that people who had been made to feel bored by copying numbers out of the phone book for 15 minutes came up with more creative ideas about how to use a polystyrene cup than a control group who had gone straight to the cup problem. People who just read the phone book for 15 minutes were more creative still. Mann concluded that a passive, boring activity is best for creativity because it allows the mind to wander. In fact, she goes so far as to suggest that we should seek out more boredom in our lives.

Psychologist John Eastwood, at York University, in Toronto, Canada, isn't convinced.

"If you are in a state of mind-wandering you are not bored," he says. "In my view, by definition boredom is aversive, it's an undesirable state." That doesn't necessarily mean that it isn't adaptive, he adds. "Pain is adaptive - if we didn't have physical pain, bad things would happen to us. Does that mean that we should actively cause pain? No." In other words, even if boredom has evolved to help us survive, it can still be toxic if allowed to fester.

"All emotions tell us how we are in the world. Boredom tells us we have pent-up, unused potential and a desire to connect to the world. Then the question is what do I do to cope with that situation?" Eastwood says.

Eastwood is interested in what boredom actually is - and his model highlights why it can be so difficult to cope with. For him, the central feature is a failure to switch our attention system into gear. The problem isn't so much a lack of stimulating things to do, but trouble focusing on anything. With nothing to focus your attention away from the passage of time, it seems to go painfully slowly. What's more, your efforts to rectify the situation can end up making you feel worse.

"People try to connect with the world and if they are not successful there's that frustration and irritability," he says. "Then they fall back into lethargy and if that doesn't work they get aroused again, so there's an oscillation between the under- and over-arousal states in an attempt to resolve the problem."

Perhaps most worryingly, says Eastwood, repeatedly failing to engage attention can lead to a state where we don't know what to do any more, and no longer care.

Eastwood's group is now exploring why the attention system fails. It's early days but they think that at least some of it comes down to personality. Boredom proneness has been linked to a variety of traits. People who are motivated by pleasure - the sensation-seeking stimulation junkies - seem to suffer particularly badly, as do anxious types. Other personality traits, such as curiosity and self-control, are associated with a high boredom threshold. What Eastwood's team would like to know is why the attention system is prone to fail in some types of people more than others, what this suggests about the neuroscience of attention failure, and whether this can tell us anything about why some people experience boredom more than others.

Whatever its cause, a failure to focus might help explain why boredom feels bad. Psychologists Matthew Killingsworth and Daniel Gilbert, at Harvard University, in the US, used a smartphone app to interrupt people at random intervals to ask them if they were on-task and how happy they felt. It turned out that the unhappiest people were those who were least focused on what they were supposed to be doing.

More evidence that boredom has detrimental effects comes from studies of people who are more or less prone to boredom. It seems those who bore easily face poorer prospects in education, their career and even life in general. They are also more likely to have problems with anger and aggression, and to partake in risky behaviours such as alcohol and drug abuse and gambling. One study even seemed to suggest that it's possible to be bored to death. Researchers from University College London looked at self-rated boredom levels in civil servants in 1985. When they followed them up in 2009, they found those who had been consistently bored were significantly more likely to have died early.

Of course, boredom itself cannot kill, it's the things we do to deal with it that may put us in danger. What can we do to alleviate it before it comes to that? Goetz's group has one suggestion.

Working with teenagers, they found that those who "approach" a boring situation - in other words, see that it's boring and get stuck in anyway - report less boredom than those who try to cope by avoiding it and mucking around. So when boredom strikes, distracting yourself from the feeling with snacks, television or social media probably isn't the best strategy.

In fact our techno-loaded, overstimulated lives might be part of the problem. Mann believes that with so many distractions we are neglecting our ability to daydream.

"We have this inbuilt mechanism to cope with boredom, but we're not using it," she says.

Wemelsfelder speculates that our overconnected lifestyles might even be a new source of boredom.

"In modern human society there is a lot of overstimulation but still a lot of problems finding meaning," she says. So instead of seeking yet more mental stimulation, perhaps we should leave our phones alone, listen to the boredom and use it to motivate us to engage with the world in a more meaningful way.

If that sounds too hard, technology itself might provide an answer in the future. Sidney D'Mello, at the University of Notre Dame, in the US, is working on a computer-based tutor for use in schools. By tracking eye position and body posture, it can tell when a person is getting bored, and will adjust its instructions accordingly. It's not difficult to imagine a similar programme sitting on every office desktop, waiting to cajole you back into action.

Ironically, it might turn out to be one kind of techno-distraction that we find incredibly easy to turn off.

Five types of boredom: what kind of 'bored' are you?

It is sometimes said that only boring people get bored. That is almost certainly unfair, but some people clearly suffer more than others. The standard way to measure a person's propensity to boredom is the boredom proneness scale (BPS), first published in 1986 by Richard Farmer and Norman Sundberg, both of the University of Oregon, in the United States (to take the test, see page 26).

So who is easily bored? Studies using the BPS indicate that men get bored more than women, that extroverts are prone, as are people with narcissistic personality traits, anxious types and those who lack self-awareness. Highly competitive sorts who are also sensation-seekers are particularly prone, which has led some to suggest a link between boredom and a heightened desire for stimulation caused by low levels of the "pleasure" neurotransmitter dopamine. On the other hand, creative people and those with a higher need for mental stimulation seem to be protected from boredom to some extent, perhaps because they do better at finding some interest or meaning in whatever they have to do.

But it's not just about your boredom threshold; how intensely you experience boredom also matters.

"You might not score high on boredom proneness but in the moment, you might still be really bored," says John Eastwood, of York University, in Toronto, Canada.

He prefers to see boredom as a state, rather than a trait, and has developed his own test - the multidimensional state boredom scale - to measure how it feels in the here and now. Nothing evokes this state quite as well as feeling trapped in a situation where you have no control over your choices. So it's not about being boring. "Only captive people get bored" might be a more accurate statement.

What's your boredom style? Boredom takes five distinct forms depending on how negative and how energetic you feel. You may experience them all, but one kind will be your speciality. Which is it?

If yes you specialise in indifferent boredom. When bored you most often feel relaxed and calm, not particularly fed up, but not engaged with the world. This is the most positive type of boredom. It may even lead to creativity.

If yes you specialise in reactant boredom. The explosive combination of high arousal and negative emotion leaves you restless, angry and in need of an outlet. This is the most damaging form of boredom.

If yes you specialise in apathetic boredom. When bored you tend to feel disengaged and unable to do anything about it. This especially unpleasant type of boredom is most similar to depression and learned helplessness.

If yes you specialise in searching boredom. Being bored makes you feel negative and restless. You actively seek ways to alleviate your boredom and if you fail to find diversions it may become reactant.

If yes, you specialise in calibrating boredom. Boredom feels unpleasant but you tend not to look for ways out of it, although you are open to boredom-reducing options if they should arise.

Take the boredom test

The boredom proneness scale was devised in 1986 by Richard Farmer and Norman Sundberg, of the University of Oregon. It is now accepted as a standard way to measure your propensity for boredom, although we have reworded several items to simplify scoring.

1) It is not easy for me to concentrate on my activities.

2) Frequently, when I'm working, I find myself worrying about other things.

3) Time always seems to be passing slowly.

4) I often find myself at a "loose end", not knowing what to do.

5) I am often trapped in situations where I have to do meaningless things.

6) Having to look at someone's home movies or travel slides bores me tremendously.

7) I do not have projects in mind all the time, things to do.

8) I find it hard to entertain myself.

9) Many things I have to do are repetitive and monotonous.

10) It takes more stimulation to get me going than most people.

11) I get a kick out of few things I do.

12) I am seldom excited about my work.

13) In many situations I can find nothing to do or see to keep me interested.

14) Much of the time I just sit around doing nothing.

15) I am not good at waiting patiently.

16) I often find myself with nothing to do - time on my hands.

17) In situations where I have to wait, such as a line or a queue, I get very restless.

18) I rarely wake up with a new idea.

19) It would be very hard for me to find a job that is exciting enough.

20) I would like more challenging things to do in my life.

21) I feel that I am working below my abilities most of the time.

22) Few people would say that I am a creative or imaginative person.

23) I have few interests and lots of spare time.

24) Among my friends, I am the one who gives up on things first.

25) Unless I am doing something exciting, even dangerous, I feel half-dead and dull.

26) It takes a lot of change and variety to keep me really happy.

27) It seems that the same things are on television or the movies all the time; it's getting old.

28) When I was young, I was often in monotonous and tiresome situations.

Below 81 You don't bore easily at all. You find amusement in the slightest thing and life is continually interesting. Lucky you!

81 to 117 You get bored sometimes, but these scores reflect average levels. Try to put those down times to good use!

Above 117 You get bored so easily you probably dropped off while reading this. On the bright side, provided you have the right kind of boredom, creativity might come more easily to you, helping you avoid an intolerably dull life.

​​New Scientist