“I know not all that may be coming, but be it what it will, I'll go to it laughing.”
― Herman Melville, Moby-Dick
Remember the times you are having a heated argument with someone, or screaming at someone, and out of nowhere you get this urge to laugh? Or even worse - you actually start laughing? Or say, someone delivers news of a death, and you give that morbid smile out of nowhere (If this doesn't sound familiar, then four for you Glen Coco! You go, Glen Coco!) One might wonder how and why situations like these warrant a response associated with humor.
Such situations are explained by the psychological concept of 'cognitive dissonance', proposed by Leon Festinger (1957). Cognitive dissonance implies a powerful motive to maintain cognitive consistency, which can give rise to irrational and sometimes maladaptive behavior. Simply put, it deals with the inconsistency between a phenomenon, and our thoughts surrounding it. For instance, people sometimes insist on having kids because they think that the kids will add meaning to their lives. However, after the child is born, if the baby cries all night, tires the parents with demands, and gives them trouble about eating food, the parents might internally feel like having the kid at that time was a mistake, but continue to externally maintain that the child had fulfilled all their notions about adding meaning to their lives, then that would indicate their cognitive dissonance.
The reasons as to why one might inappropriately respond with laughter in serious situations are varied. Laughter is often associated only with humor and happiness. However, it also acts as social enabler. When faced with situations where one doesn't impulsively know how to respond, the first response may be that of a laugh, which could be indicative of trying to connect with other individuals in that situation, than an actual reaction to the stimulus. Further, various studies have shown that laughter is means to reduce stress through production of positive affect. Therefore, when one smiles at something incongruously, it could be to ease out on the stress of information that has just been conveyed.
Another facet of inappropriate laughter is nervous laughter. People may also laugh in events that cause nervousness, so as to attain an emotional homeostasis, i.e. to tone down the feelings of nervousness. A function similar to stress reduction through positive affect might be at play here. Conversely, we would think that the response of laughter to tickling is associated with humor. However, laughing upon being tickled is a sign of submissiveness! While people roll around laughing, upon being tickled, it also makes them uncomfortable. This is because the ticklish spots on a human body are the same as those most susceptible to injury through attack, and laugher in this case scenario is nothing more than a conveyance that tickling is innocuous, and not really an attack. It is still a panic response, nevertheless.
Yet another theory, which might explain 'out of place' laughter could be the pleasure of the self-fulfilling prophecy. When one anticipates a bad outcome, or awaits some bad news, and that comes out to be true, the satisfaction of being right may be associated with positive affect, the outcome of which can be acts like smiling out of place.
Cognitive dissonance could also be prominent in instances where individuals continue to laugh at the material of certain comedians, despite a quality drop. It could be due to their self-proclaimed love for the comedian in the past, which inhibits them from accepting that they do not like the joke, and leads them to uncomfortably accept that they find the material funny. This is perhaps why deterioration of material quality does not reduce the popularity of comedians. This may also be true in case of shows such as The Big Bang Theory, where critics have accused the latest 3-4 seasons of not being at par with the humorous content of initial seasons. However, the show's viewership has progressively only increased, despite such an assessment. Thus, it may be inferred that individuals have continued watching the show despite a drop in humor quality, only due to their initial commitment to it.
To sum it up, you may face various incidences where laughter does not belong, but persists. That doesn't essentially mean that something is wrong with you, but that your cognition is preparing you to cope with the stressor at hand by stimulating positive emotions. Such occurrences are more common than one might think, and there is an actual WikiHow page that tells people what to do when they feel that unwarranted smile coming along. So the next time you want to approach someone, without giving that Joker smile, you would know what to do!