An upcoming study in the Quarterly Review of Biology, describes the evolutionary origins of two distinct types of laughter. Biologists from Binghamton University delineate laughter which is stimulus-driven and laughter which is self-generated and strategic.
Laughter that occurs during everyday social interaction in response to banal comments and humorless conversation is now being studied. How this type of humor relates to other types of humor is the object of study. Using empirical evidence from across disciplines, including theory and data from work on mirror neurons, evolutionary psychology, and multilevel selection theory, the researchers detail the evolutionary trajectory of laughter over the last 7 million years.
According to the authors, laughter can arise from non-serious social incongruity promoted by community play which evolved from ape play-panting sometime between 4 million years ago and 2 million years ago during fleeting periods of safety. Such non-serious social incongruity, it is argued, is the evolutionary precursor to humor as we know it.
However, neuropsychological and behavioral studies have shown that laughter can be more than just a spontaneous response to such stimuli. Around 2 million years ago, human ancestors evolved the capacity for willful control over facial motor systems. As a result, laughter was co-opted for a number of novel functions, including strategically punctuating conversation, and conveying feelings or ideas such as embarrassment and derision.
This study looks at different types of humor and how it has related in social situations. Humans have a range of ways that humor can affect their lives, moods and attitudes and can voluntarily access laughter and utilize it for their own ends, including smoothing conversational interaction, appeasing others, inducing favorable stances in them, or laughing at individuals who are not liked.
Another recent study in the Journal of Early Human Development, attempts to differentiate spontaneous smiles from spontaneous laughs (smiles accompanied by vocal sounds) in infants. The goal was to try to understand the early beginnings of laughter.
Cure vs Disease
Interestingly enough, looking at laughter in the literature produces both the idea of humor as a cure and as a disease. In the area of humor as cure, a number of studies deal with the use of humor as a adjunct to treatment. In a recent article in Oncologist, humor is described as a way to help to ease the pain and show the human side of the health care team. It can help the patient, support caregivers and encourage the healing process in cancer patients. Whether the patient uses humor to lighten the mood of a difficult consultation with their physician, or health care workers use it to help cheer each other through the day, humor and laughter can be valuable tools. Humor can soften the isolation experienced by both patients and staff. When used sensitively, respecting the gravity of the situation, humor can build the connection among the caregiver, patient, and family. However, it is pointed out that insensitive joking is offensive and distressing.
On the pathology side, a case report in last month's Movement Disorders Journal described acute pathological laughter. Pseudobulbar affect is a condition characterized by uncontrollable episodes of inappropriate laughing or crying that are disproportionate and discordant to the situation at hand. The article describes a 16-year-old woman presenting with acute pathological laughter in the context of CNS demyelinating disease. Brain MRI scans obtained before and after the onset of this symptom demonstrated acute gadolinium-enhancing lesions in the cerebral peduncles. The etiology of this condition remains theoretical; however, the results here provide further insights into the pathways of emotional control.
Research this month from Stanford University used event-related functional MRI to evaluate humor in the personality dimensions, introversion-extroversion and emotional stability-neuroticism. The goal was to look at putative neural and behavioral associations between humor appreciation and these personality dimensions.
The analysis showed extroversion to positively correlate with humor-driven blood oxygenation level-dependent signal in discrete regions of the right orbital frontal cortex, ventrolateral prefrontal cortex, and bilateral temporal cortices. Introversion correlated with increased activation in several regions, most prominently the bilateral amygdala. Although neuroticism did not positively correlate with any whole-brain activation, emotional stability (i.e., the inverse of neuroticism) correlated with increased activation in the mesocortical-mesolimbic reward circuitry encompassing the right orbital frontal cortex, caudate, and nucleus accumbens.
These findings tie together existing neurobiological studies of humor appreciation and are compatible with the notion that personality style plays a fundamental role in the neurobiological systems subserving humor appreciation. For these characteristics, the study shows that personality can predict activity in reward and emotional regions associated with humor.
Unfortunately. the medical literature contains a dearth of information on humor, and very little research has been conducted on this common aspect of human communication.
Some quotes on Humor
There's no trick to being a humorist when you have the whole government working for you.
Humor is the only test of gravity, and gravity of humor; for a subject which will not bear raillery is suspicious, and a jest which will not bear serious examination is false wit.
Humor is just another defense against the universe.
Humor is by far the most significant activity of the human brain.
Edward De Bono
Humor is also a way of saying something serious.
T. S. Eliot
Humor is a rubber sword - it allows you to make a point without drawing blood.
Humor is the great thing, the saving thing. The minute it crops up, all our irritations and resentments slip away and a sunny spirit takes their place.
Our five senses are incomplete without the sixth - a sense of humor.
Imagination was given to man to compensate for what he is not, and a sense of humor to console him for what he is.
Good humor is a paradox. The unexpected juxtaposition of the reasonable next to the unreasonable.
Some quotes on laughter
The human race has one really effective weapon, and that is laughter.
The most wasted of all days is one without laughter.
e e cummings
Laughter is the closest distance between two people.
Laughter gives us distance. It allows us to step back from an event, deal with it and then move on.
You can't deny laughter; when it comes, it plops down in your favorite chair and stays as long as it wants.
Laughter is the sun that drives winter from the human face.