Aggression and violence pose a most difficult challenge to human welfare. Violence and crime in general have become worldwide public health problems, and highly publicized events in the US underscore intense public concern. Therefore, violence in the community has obvious social relevance for the political, criminal justice, and health care systems.

Aggressive and impulsive behavior that leads to criminal and antisocial acts may be the product of a failure of emotion regulation [1]. Healthy individuals are better at regulating their negative emotional states and benefit from restraint-producing environmental cues that also serve a regulatory role, such as facial and vocal signs of anger and fear. As accurate interpretation of facial expressions is important for social interaction, one would expect that individuals who have trouble interpreting facial expressions of emotions would be less socially competent and fail to adequately modulate behavior according to social context. Previous studies could show that aggressive individuals tend to generally interpret actions and intentions of others as involving anger and hostility [2], [3]. Additionally, they were more likely to perceive anger in emotionally neutral faces and show a negative emotional bias for ambiguous facial expressions [4]. Moreover, intimate partner violence perpetration has been related to a specific tendency to misperceive the partner's expressions of happiness as negatively valenced [5].

One important symptom, possibly related to outbreaks of aggression and violence, particularly in adolescents and young adults, may be “Gelotophobia” (from gelos, Greek for laughter), which is a young and still relatively unexplored construct. Gelotophobia is defined as the fear of other persons' laughter, meaning that individuals with gelotophobia connote laughter in their presence generally negatively and tend to assume that it is directed at them. They are hypervigilant towards signs of derision and persons that might ridicule them. They also tend to believe being strange by nature and to be strikingly emotionally inexpressive [6], [7]. Gelotophobia has attracted attention, because the pattern of emotion-related characteristics in gelotophobia seems to resemble those of violent individuals. Recent data suggested that individuals with higher levels of gelotophobia feel weak at downregulating their negative affect, and the attempts they typically make to manage their emotions are also considered inefficient by experts [8]. Moreover, they may be more likely to experience anger, also in emotionally neutral interpersonal situations [8], and have a tendency to recall interpersonal situations with a higher intensity of negative feelings [9]. Gelotophobia has also been related to being the victim of aggressive encounters. Experiences of being bullied or ridiculed initially were even suspected to cause or facilitate the development of gelotophobic symptoms [7], [10]. The suspicion that gelotophobia may be related to aggression and violence had recently been fuelled by anecdotal evidence suggesting that perpetrators of violent acts such as school shootings had a horror of being mocked and may have taken revenge for having been laughed at [11], [12].

However, the empirical indications of relationships of gelotophobia to emotion-related deficits and dispositions putatively relevant to aggressive behavior are preliminary in so far as they were obtained in studies that were correlational in nature, using convenience samples with a great majority of subjects having had low and sub-clinical levels of gelotophobia. Additionally, most studies did not control for psychiatric comorbidity. Like many other psychiatrically relevant symptoms, gelotophobia is considered to occur along a continuum in nonclinical populations, with levels exceeding a certain threshold considered as clinically relevant [12], [13]. Despite a growing number of scientific publications on gelotophobia, explorations of its relations to or overlaps with standard psychiatric diagnoses are still sparse. The most obvious overlap may be with social phobia, since both diagnoses share a preoccupation with fear of negative evaluation, humiliation, and embarrassment, a tendency to avoid social situations, and anxiety-related symptoms of physiological arousal [9]. However, some characteristics of gelotophobia may be not present in social phobia, that is, the emotional inexpressiveness, the belief to be strange and ridiculous by nature, and the threatening potential of every laughter, also from most familiar people and in all social situations [7], [9], [14].

Several features of gelotophobia that can be found in the case descriptions of Titze [7], such as the reduced emotional expressiveness, the belief of being strange by nature, and an attributional bias of the world as hostile and threatening, may suggest relationships to schizophrenia spectrum personality disorders. A first indication of potential overlaps was provided by a study indicating that psychiatric patients with schizophrenia and personality disorders scored higher on the standard gelotophobia instrument than other diagnostic groups such as mood and anxiety disorders [15]. However, no studies examining the prevalence of schizophrenia spectrum personality disorders in individuals classified as gelotophobic have been reported to date. The potential overlap of gelotophobia with schizophrenia spectrum personality disorders appears particularly likely when considering violence related issues and the proneness to anger and aggression. Several studies demonstrated that increased Cluster A personality disorder symptoms correlated significantly with violence [16], [17]. Especially delusions of “threat/control override” not only in mentally disordered subjects but also as a constituent of a paranoid personality style and referential style represent a significant risk factor for violence [18].

The primary goal of the present study was to examine the potential association between gelotophobia and anger and aggression proneness. In addition, overlaps with mental disorders that have been previously linked to gelotophobia (like social phobia) or provide a possible clinical risk for gelotophobia and violence such as Cluster A personality disorders were examined.

Inspired by anecdotal evidence that some outbreaks of aggression and violence may be related to a fear of being laughed at and ridiculed, the present study examined the potential association between gelotophobia and anger and aggression proneness. In addition, overlaps with mental disorders that have been previously linked to gelotophobia (like social phobia) or provide a possible clinical risk for gelotophobia and violence such as personality disorders were examined.

The findings show that gelotophobia is associated with several deficits in the typical handling of an individual's own affective states. Gelotophobic participants indicated that they felt weak at regulating their emotions to a greater extent than non-phobic controls did. Moreover, their typical approaches to manage their emotions in emotion-laden situations are considered inefficient by experts. The indication of less efficient strategies in the management of affective states is further corroborated by the finding that gelotophobics more often try to handle their emotions by suppressing emotion-expressive behavior than their non-phobic counterparts. By contrast, no differences were found for the use of cognitive reappraisal. These results directly replicate findings of previous studies that were obtained in the lower, sub-clinical range of gelotophobia using it as a continuous variable [8] and are in agreement with observations from clinical encounters that gelotophobics are anxious to maintain an inconspicuous appearance [7]. As expressive suppression involves the inhibition of only the behavioral component of one's emotional response, it is generally regarded an inefficient strategy for the downregulation of negative feelings [33]. Deficits in the perception of one's emotions (indicated by high alexithymia scores [26]) may hinder their adequate handling [27].

Dysfunction in basic emotion regulation processes are assumed to predispose to aggression and violence [1]. More specifically, deficient ability to identify one's emotional state (as assessed by the TAS) was linked to aggression in psychiatric patients [34]. Emotional inexpressivity may further contribute to aggressive behavior insofar as a failure to express emotions in a healthy way leads to a reliance on maladaptive ways of expressing emotions, such as through verbal and physical aggression [35].

Previous experimental results had suggested that anger may show a certain predominance in gelotophobics when they are involved in interpersonal situations [8]. This was confirmed by the present finding of higher levels of trait anger in the gelotophobia than in the non-phobic control group. Trait anger plays a role in aggressive behavior and violence, particularly when coupled with defective emotion regulation [36], [37].

Finally, the findings also more directly indicated a link between gelotophobia and aggression, showing a stronger tendency towards overt aggression in gelotophobics than in non-phobic controls, at least according to self-report. The findings were similar for “pure”, reactive, and instrumental aggression (except that in women the difference in reactive aggression was weaker and fell below the significance threshold). Participants in the gelotophobia group also indicated being the victim of aggressive encounters to a greater degree than their non-phobic counterparts. At the first glance, this may well fit the fear of being laughed at and ridiculed. Initially, it was hypothesized that experiences of being bullied or ridiculed may cause or facilitate the development of gelotophobic symptoms [7], [12], but gelotophobia could not be traced back to repeated or intense experiences of having been laughed at and ridiculed in childhood and youth [13]. Instead, it has been proposed that gelotophobics may overestimate incidents of having been bullied, because they misinterpret harmless comments as offensive [20]. The latter interpretation may be in accordance with the overlap of gelotophobic symptoms with schizophrenia spectrum personality disorders (particularly paranoid symptoms).

One aim of the study was to further assess the overlap between gelotophobia and other mental disorders, especially schizophrenia spectrum personality disorders and social phobia. Nestor et al. [18] defined four fundamental personality dimensions that increase the risk for violence and may be specifically important as clinical risk factors among persons with mental disorders such as schizophrenia and personality disorders. The first two dimensions relate to deficits in the regulatory functions of impulse control and affect regulation, which are core deficits in all mental disorders and can also clearly be seen in our group of gelotophobics. The last two dimensions relate to personality surface traits such as narcissistic injury (threatened egotism) and paranoid cognitive personality style, which elevate the rates of violence especially in schizophrenia spectrum disorders. The current study showed that 80% of the subjects in the gelotophobia group had an additional diagnosis of social phobia and/or Cluster A personality disorder, in which these dimensions are inherent.

Interestingly, the classification into Cluster A personality disorder and/or social phobia did not show significant differences regarding anger-proneness or aggressive behavior among the sub-groups within the gelotophobia group. That is, none of these diagnoses did explain additional variance of overt aggressive behavior as compared to gelotophobia alone. However, a higher victimization score was observed in the combined social phobia plus Cluster A personality disorders group. In a recent study by Raine et al. [38] the relationship between schizotypal personality and aggression in children was mediated by peer victimization. Typical symptoms of Cluster A personality disorders and social phobia such as social anxiety, paranoid ideation, blunted affect, and odd behavior can easily lead to victimization in children and finally result in reactive aggression as a defensive response to provocation [39]. However, due to the potential misinterpretation of social situations in individuals with schizophrenia spectrum personality disorders and gelotophobia, it would be necessary to use peer ratings of victimization (instead of self-report) in order to reliably test the model proposed by Raine et al. [38] of a viscous cycle of schizotypal features and victimization that may eventually erupt into violence.

Being the first study examining the interrelationships between gelotophobia, schizophrenia spectrum personality disorders, and clinically diagnosed social phobia, the study needs to be interpreted with caution, mainly because the sample size is limited and all participants were university students. Therefore, the results may not generalize to other populations.

Aggression is closely linked to hypervigilance towards stimuli that could be perceived as threatening [39], [40]. This feature which is inherent in social anxiety and paranoid ideation may be particularly evident in the fear of other persons' laughter. Taken together, therefore, gelotophobia could be a core symptom for aggressive behavior underlying different mental disorders such as social phobia or Cluster A personality disorders.