Contagious yawning and psychopathy
Yawning is a stereotyped behavior that, in our evolutionary history, has clear, deep roots as evidenced by its proliferation in mammals as well as many other vertebrates. It is clearly characterized by long inspiration followed by a shorter expiration. While literature concerning the pharmacology and functional anatomy of yawning is not lacking, the primary facet of yawning of interest is the phenomena of contagious yawns, specifically within the context of psychopathology.
Contagious yawns, which are spurred by yawn, thinking, hearing, reading, or observing another conspecific, have been linked to empathy. They are even documented in other familiar animals such as Pan Troglodytes and Canis Familiaris and have been linked to empathy. The anat-omy and pharmacology of yawning and its contagious nature are beginning to be investigated, with oxytocin playing a large role as well as the posterior cingulate cortex (PCC), precuneus, bilateral thala-mus, and parahippocampal gyrus (PHG). Interestingly, Schürmann found that the mirrorneuron system is not directly activated in contagious yawning, suggesting that the action is automatic and not imitated. Norscia and Palagi found that people show a large susceptibility to contagious yawns when elicited by a related individual in terms of occurrence and frequency of yawns. For strangers, they found that people show a marked latency period of contagious yawns, strongly suggesting a component of familiarity involved with the contagion.
Variations in susceptibility to contagious yawning are already known to occur in certain populations. Age is known to affect the likelihood of contagious yawning; as age increases, contagious yawning decreases. Further, children on the autism spectrum are less likely to demonstrate contagious yawning, which is speculated to have a strong relationship to the empathetic deficits seen in this population.
Empirical support for yawning having its evolutionary roots in empathic behavior is growing. Psychopathic traits, then, become a curious angle in which to view contagious yawning in our species. Psychopathy is characterized by a general antisocial lifestyle including being selfish, manipulative, impulsive, fearless, callous, domineering, and particularly lacking in empathy. The disorder is typically assessed via the Psychopathic Check List Revised (PCL-R) developed by Hare or the Psychopathic Personality Inventory (PPI-R) developed by Lilienfeld and Widows. Psychopathy and its close relative Antisocial Personality Disorder are found overwhelmingly in males. Additionally, psychopathy carries specific brain abnormalities including structural and functional impairments of the orbit of rontal ventromedial prefrontal cortex as well as the amygdala.
The PPI-R operationalizes two discrete components within psychopathy: a primary (affective) and secondary (behavioral) facet, where the primary facet encompasses features including cruelty, lack of affect and empathy, while the secondary facet encompasses features such as impulsivity and aggression. Psychopaths demonstrate an overall small but marked decrease in the ability to recognize emotion in others, which is also associated with decreased amygdalar function, particularly with fearful faces. Kosson showed a slight overall decreased ability to recognize emotion, but a large deficit in recognizing disgust in others when the task involved non-verbal responses. It has also been shown that psychopaths fail to exhibit a conditioned response to aversive Pavlovian conditioning, which suggests deficiencies in amygdala dependent memory.
What sets psychopathy apart from its close relatives Conduct Disorder and Antisocial Personality Disorder is its distinct emotional component. That is, psychopathy involves a prevalent emotional profile consisting of a considerable reduction in or lack of empathy. Psychopathy has also been found to be inversely related to the ability to perceive emotion (in both male and females) and managing emotion (only in men).
Given the nature of psychopathy and yawning discussed herein, the current study aims to examine the relationship between contagious yawning and psychopathic traits. This will be examined both by a yawning paradigm designed by the current researchers as well as an emotion-related startle paradigm (ERS) previ-ously used in Anderson, Stanford, Wan, and Young (2011). Affective potentiation of the acoustic startle reflex (by Electromyograph [EMG] and Galvanic skin response [GSR]) is one of the most prominent psycho-physiological measures of amygdalar responsiveness. Psychopaths reliably demonstrate an impairment of potentiation of the startle reflex, while healthy controls reliably potentiate with negative affective valence and attenuate the fear response with positive affective valences connected the lack of potentiated startle in psychopathy to the emotional facet of the PCL-R while the behavioral facet was found to be unrelated. Further, given the growing evidence that contagious yawning and empathy are evolutionarily related, a connection between psychopathy and yawning maintains sufficient precedence. To our knowledge, such an examination has not been done in high psychopathic trait individuals, nor have contagious yawning been addressed using ERS. In our case, we expect to find a connection between psychopathic traits and a decreased susceptibility to contagiously yawn.
Contagious yawning and psychopathy by Brian K. Rundle , Vanessa R. Vaughn, Matthew S. Stanford.