The highest levels of arousal and negative emotions. A person in a reactant boredom state has a strong motivation to escape his or her boring situation and avoid those responsible for it (such as teachers or a boss). Reflects significant restlessness and aggression. There are persistent thoughts about specific, “more highly valued alternative situations.”
Erich Fromm and other thinkers of critical theory speak of boredom as a common psychological response to industrial society, where people are required to engage in alienated labor. According to Fromm, boredom is "perhaps the most important source of aggression and destructiveness today." For Fromm, the search for thrills and novelty that characterizes consumer culture are not solutions to boredom, but mere distractions from boredom which, he argues, continues unconsciously.[29] Above and beyond taste and character, the universal case of boredom consists in any instance of waiting, as Heidegger noted, such as in line, for someone else to arrive or finish a task, or while one is travelling somewhere. The automobile requires fast reflexes, making its operator busy and hence, perhaps for other reasons as well, making the ride more tedious despite being over sooner.
^ Vodanovich, Stephen J. (November 2003) "Psychometric Measures of Boredom: A Review of the Literature" The Journal of Psychology. 137:6 p. 569 "Indeed, a shortcoming of the boredom literature is the absence of a coherent, universally accepted definition. The lack of an agreed-upon definition of boredom has limited the measurement of the construct and partly accounts for the existence of diverse approaches to assessing various subsets of boredom."
One more key element of boredom is control. Boredom often occurs when you have little control over your situation. Waiting rooms, lectures, and airline gates are all places where you have little control over your situation. Normally, we react to unpleasant situations by changing the situation. If you don’t like a book you are reading, for example, you close it and do something else. Boredom happens when you are unable to change the situation.  
This example leads to another key aspect of boredom. As Eastwood, Frischen, Fenske, and Smilek point out, bored people become aware of their difficulty concentrating. As a result, bored people often try to amuse themselves by daydreaming and letting their mind wander. Interestingly, while mind wandering helps people to keep their minds occupied, studies suggest that the more your mind wanders, the more bored you feel. The idea is that you recognize that this daydreaming is meant to occupy your mind, and so you realize that the situation is boring.

The people who heard the barely noticeable TV rated themselves as more bored than either the ones who heard the loud TV or heard no soundtrack. The idea is that both the loud TV and the soft TV were distracting, but for those who heard the loud TV it was clear why they were distracted from the article. Thus, they may have been frustrated with the noise, but they were not bored. Those who heard the soft soundtrack had difficulty concentrating, but they were not sure why, and so they attributed the difficulty concentrating to boredom.

The French term for boredom, ennui, is sometimes used in English as well, at least since 1778. The term ennui was first used "as a French word in English;" in the 1660s and it was "nativized by 1758".[7] The term ennui comes "from French ennui, from Old French enui "annoyance" (13c.), [a] back-formation from enoiier, anuier.[7] "The German word for "boredom" expresses this: Langeweile, a compound made of lange "long" and Weile "while", which is in line with the common perception that when one is bored, time passes "tortuously" slowly.[8]
“Boredom is a flight from what is important. Like workaholism and perfectionism, it is a way of distracting yourself from inner experiences. It occurs when you look outward and do not find anything to engage your attention. Instead of feeling your emotions - becoming aware of the functioning of your energy system - you become bored. Boredom ... is a flight from your higher potential. It is fear of the transformation that wants to occur, and will occur in you, when you explore your emotions. It is your resistance to spiritual growth.”
"If this is one of your tricks..." Like the time Torin had ordered hundreds of blow-up dolls and placed them throughout the fortress, all because Paris had foolishly complained about the lack of female companionship in town. The plastic "ladies" had stared our from every corner, their wide eyes and let-me-suck-you mouths taunting everyone who passed them.
Then, after a baseline EEG test measuring normal brain activity, the researchers assigned the participants a tedious task: they had to turn eight virtual pegs on a screen as the computer highlighted them. This activity lasted approximately 10 minutes, during which time the researchers used EEG caps to measure participants’ brain activity as they carried out the boring task.

"Meh" is an interjection used as an expression of indifference or boredom. It may also mean "be it as it may".[40] It is often regarded as a verbal shrug of the shoulders. The use of the term "meh" shows that the speaker is apathetic, uninterested, or indifferent to the question or subject at hand. It is occasionally used as an adjective, meaning something is mediocre or unremarkable.[41]
“To me, at least in retrospect, the really interesting question is why dullness proves to be such a powerful impediment to attention. Why we recoil from the dull. Maybe it’s because dullness is intrinsically painful; maybe that’s where phrases like ‘deadly dull’ or ‘excruciatingly dull’ come from. But there might be more to it. Maybe dullness is associated with psychic pain because something that’s dull or opaque fails to provide enough stimulation to distract people from some other, deeper type of pain that is always there, if only in an ambient, low-level way, and which most of us spend nearly all our time and energy trying to distract ourselves from feeling, or at least from feeling directly or with our full attention. Admittedly, the whole thing’s pretty confusing, and hard to talk about abstractly…but surely something must lie behind not just Muzak in dull or tedious places any more but now also actual TV in waiting rooms, supermarkets’ checkouts, airport gates, SUVs’ backseats. Walkman, iPods, BlackBerries, cell phones that attach to your head. This terror of silence with nothing diverting to do. I can’t think anyone really believes that today’s so-called ‘information society’ is just about information. Everyone knows it’s about something else, way down.”

Second, boredom typically occurs when people have trouble focusing their attention and they believe the reason for this difficulty is in the environment. When sitting in the airport, for example, there is probably a lot going on. There are people having conversations that you could listen to. You probably have something to read. There may be televisions showing the news. But, the stress of waiting for a delayed flight often makes it hard to concentrate, and so your mind jumps from one thing to another. You assume that this is caused by the environment, and so you feel boredom.