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By far the best kind of corroboration a theory could hope for comes from those who initially set out to disprove it; but the second best kind comes from researchers unaware of it who nevertheless confirm its predictions. Where the diametric model of the mind is concerned, the latter now seems to have occurred in relation to exaggeration in facial expression.
The first published account of the diametric model of mental illness (2002) began by arguing that gaze-awareness was a plausible evolutionary origin for mentalism understood as our evolved ability to understand others’ behavior and expressions—facial ones included—in mental terms. And as a new study by Shota Uono, Wataru Sato, and Motomi Toichi points out, people who are sensitive to others’ facial expressions “achieve high social status, are successful in business, and experience high subjective well-being and low depression.” Clearly, being able to read the real face book pays!
But where any kind of reading is concerned—and facial expression is a quintessential means of mind-reading for human beings—there is always the danger of mis-reading. In the past and where mental illness was concerned, mis-reading other people was usually assumed to be a simple deficit. Indeed, as the study from which I am quoting goes on to note, individuals with autism spectrum disorder (ASD) "have difficulty recognizing others’ facial expressions and do not spontaneously attribute mental states to others.” And much the same was claimed to be the case with those suffering from psychotic spectrum disorder (PSD).
Nevertheless, according to the diametric model of the mind, facial signals can be mis-read in the exactly opposite way in PSD to that seen in ASD: by over-recognition and spontaneously attributing mental states to others above and beyond what is actually warranted—what you could call hyper-mentalism. As this paper notes, “studies have demonstrated that individuals with schizophrenia perceive the gaze direction of others in a self-referential manner; i.e., they have a greater tendency to perceive an averted gaze as a direct gaze compared with controls.” Indeed, you could see the common paranoid delusion of being watched or spied on as the epitome of exaggerated gaze-awareness—and as the opposite to the neglect of, and indifference to, others’ gaze that is symptomatic of ASD.
This study presented what it calls “dynamic and static facial expressions and asked participants to change an emotional face display to match the perceived final image.” The researchers “hypothesized that the exaggerated perception of facial expressions would be specifically related to the tendency to over-attribute mental states to others in individuals with schizophrenic characteristics.” Specifically, the researchers “investigated the relationship between exaggerated perception of dynamic facial expressions and schizophrenic characteristics in a normal population.” To test perception of facial expressions, they used an experimental paradigm used to investigate perception of facial expressions in ASD:
We presented dynamic and static facial expressions at subtle, medium, and extreme intensities, and asked participants to change an emotional face display to match the perceived final image from dynamic and static facial expression stimuli … After the experiment, participants completed the Schizotypal Personality Questionnaire (SPQ), which measures various aspects of schizophrenic characteristics.
The researchers “predicted that individuals with high schizotypal traits would perceive dynamic facial expressions as more exaggerated than did those with few schizotypal traits.”
Forty-six undergraduate and graduate students at Kyoto University participated in this study, 26 of them males.
As the figure above illustrates, the researchers report that
our results demonstrated that individuals who scored high on schizotypal traits perceived dynamic facial expressions as more exaggerated than those who had few schizotypal traits. These results are consistent with our hypothesis that the exaggerated perception of dynamic facial expressions would increase in accordance with the degree of schizophrenic characteristics. Interestingly, our results also showed that static facial expressions were perceived as more exaggerated in individuals with high schizotypal traits.
As the authors note, this is the first evidence indicating that individuals with psychotic traits generally perceive others’ emotional facial expressions in an exaggerated manner. And as paranoid delusions of being watched or spied on suggest, they go on to add that “Our results further revealed that, among the sub-components of schizotypal traits, paranoia, which consists of the suspiciousness and ideas of reference scales, was related to the exaggerated perception of facial expressions.”
Indeed, the authors implicitly go the whole hog with the diametric model when they add that
Although both individuals with ASD and schizophrenia exhibit impaired social cognition, it is possible that the underlying psychological mechanisms related to the social cognition impairments differ between ASD and schizophrenia. The lack of spontaneous mental state attribution to others would cause social cognition dysfunction in individuals with ASD, while the tendency to over-attribute mental states to others might contribute to the impairments in those with schizophrenia. Consistent with this proposition, the opposite relationship between autistic and schizotypal traits in the exaggerated perception of facial expressions suggests that ASD and schizophrenia are at two extremes of the continuum with respect to social cognitive abilities, such as the attribution of mental state.
Finally, as I have pointed out in a number of previous posts, hyper-mentalism has its positive side. As these authors comment, “Based on the possibility that exaggerated perception of facial expressions is useful to effectively detect others’ emotions, the current study suggests that high paranoia (e.g., ideas of reference and suspiciousness) has a positive effect on detecting and recognizing emotion from others’ faces.” Indeed, it has, and as I pointed out in one particular post, borderline personality subjects actually perform better in games where interpretation of facial expression is concerned compared to normal controls.
Clearly, mentalizing ability cuts both ways: like just about every other evolved parameter you care to mention (blood-pressure, sugar, temperature etc.) there is an optimum level, and deviations in either direction—higher or lower—are pathological. But only the imprinted brain theory explains why.
(With thanks to Bernard Crespi and Ahmad Abu-Akel for bringing this to my attention.)
