The intergenerational transmission of elaborate cultural practices will typically possess low fidelity unless supported by innate (i.e., hard-wired) neural substrates. The institution of shamanism is akin to other identifiable cultural practices such as culinary traditions, sexual habits, and war rituals. The universality of such social practices seemingly is maintained by innate behavioral tendencies: hunger for culinary traditions, erotic feelings for sexual practices, and tribalism and aggression for war rituals. Without the constant presence of certain innate emotional systems, each cultural practice would eventually fade and disappear. The author is cleverly aware of this possibility and surmises that the “cognitive underpinnings of magic and religion” play a role in maintaining shamanism. I would argue, however, that the hypothesized neural substrate behind shamanism is characterized better by the phenotype of psychosis (while also recognizing that psychosis is closely related to magic and religion).
Cultural factors undoubtedly play a prominent role in creating the institution of shamanism, and it certainly is possible that such an identifiable social role would inevitably attract non-psychotic practitioners; however, it also cannot be discounted that there is an anthropological literature replete with examples of psychotic-like behaviours in the personal histories of shamans (Ackerknecht Reference Ackerknecht1943; Devereux Reference Devereux1961a; Laubscher Reference Laubscher1937).
Over the years, I have learned that two common misconceptions prevent experts from appreciating a connection between psychosis and shamanism. The first is a failure to recognize that the majority of psychotic individuals do not live in a persistently disorganized mental state (this was true even before the advent of effective treatments). This means that most individuals with a psychotic disorder (e.g., schizophrenia, bipolar disorder) would have been capable of being shamans, most of the time. In any Gaussian distribution of phenotypic traits, the extremes do not typically represent the most adaptive phenotype. Similarly, the most grossly psychotic individuals would not necessarily have been shamans. However, when one combines the frequency of schizophrenia, schizotypal personality disorder (i.e., a milder form of schizophrenia), and bipolar spectrum disorders, a non-trivial frequency of aspirant shamans is produced (approaching 5%–10% of the general population). It is precisely this cluster of heritable diagnoses that have a special affinity for magico-religious discourse, as evident in their historical participation in cults, paranormal beliefs, possession states, and spiritual hallucinogenic use – social phenomena considered to be at the outskirts of both religion and psychosis. Accordingly, the eighteenth-century “epidemic” of schizophrenia was probably caused by a convergence of societal changes (i.e., secularization, industrialization, and greater government accountability), which intensified the disabling aspects of psychosis.
The second misconception around shamanism is an underappreciation for the similarity of the cognitive substructure of psychosis to basic religious ideation. According to cognitive theorist Pascal Boyer, a religious idea must incorporate a fact that specifically contradicts at least one defining characteristic of an ontological category (Boyer Reference Boyer2001). For example, a ghost may have the form of a person, but it lacks one essential quality (i.e., physical matter) integral to its ontological category (i.e., persons). Research studies consistently have found that about 60% of delusions and hallucinations contain outright religious themes (Rudaleviciene et al. Reference Rudaleviciene, Stompe, Narbekovas, Raskauskiene and Bunevicius2008). If one broadens the definition of religiosity and tallies magico-religious themes, however, the frequency turns out to be much higher. For example, our research team observed that 25 of 26 patients with schizophrenia possessed plausible magico-religious themes inside of their delusions and hallucinations (Polimeni Reference Polimeni2012, p. 191).
The target article concludes that shamanism is evolutionary “cheesecake,” but there are several compelling reasons to believe that the shamanistic phenotype is not a zero-sum game. One problem in the evolutionary study of behaviors is that there is often a failure to separate incidental actions from evolutionary effective activities. For example, not every manifestation of anger is evolutionarily advantageous, but, on average, the sum total of angry expressions provides phenotypic advantage. Similarly, not every shamanistic endeavor would have necessarily been evolutionarily advantageous. My own view is that some of the more sporadic shamanistic activities may have been more evolutionarily impactful (i.e., divining, out-group suspiciousness) compared with some of the more conspicuous shamanistic practices (spiritual healing, weather prophesies), which may simply have been incidental behaviors tolerated by evolutionary processes. Another notable feature of shamanism is trance, which has been neglected in most theories about shamanism, but skillfully examined in the target article.
One interesting idea in the target article is framing shamanism as one of the oldest professions; however, I propose that the better characterization – in keeping with ethological principles – is task specialization (similar to task specialists of eusocial insects) (Polimeni & Reiss Reference Polimeni and Reiss2002). It is noteworthy that two genetic mechanisms theoretically able to support task specialization (i.e., heterozygote advantage and assortative mating) also may be relevant in the heritability of schizophrenia (Polimeni Reference Polimeni2012).
Where schizophrenia is common, shamans are not; and where shamans practice, insanity becomes spiritual. The distinguished evolutionary psychiatrist John Price has argued that many of the evolutionary advantages of prehistoric religions are specifically dependent on contact with the gods being restricted to a sole individual (Stevens & Price Reference Stevens and Price2000). Hunting and gathering societies are often forced to make arbitrary (i.e., random) decisions (e.g., when to plant crops, which new direction to hunt, if and when to attack or flee another group); having a sense that the gods are backing one choice puts the entire tribe on the same page, working together. The evolution of shamanism is indeed complex, and the target article capably examines some of the cultural aspects maintaining the institution of shamanism; however, it arguably misses the spark that gets the whole process going – the occurrence of intrusive psychotic experiences (containing magico-religious themes) in those individuals typically destined to be shamans.
The intergenerational transmission of elaborate cultural practices will typically possess low fidelity unless supported by innate (i.e., hard-wired) neural substrates. The institution of shamanism is akin to other identifiable cultural practices such as culinary traditions, sexual habits, and war rituals. The universality of such social practices seemingly is maintained by innate behavioral tendencies: hunger for culinary traditions, erotic feelings for sexual practices, and tribalism and aggression for war rituals. Without the constant presence of certain innate emotional systems, each cultural practice would eventually fade and disappear. The author is cleverly aware of this possibility and surmises that the “cognitive underpinnings of magic and religion” play a role in maintaining shamanism. I would argue, however, that the hypothesized neural substrate behind shamanism is characterized better by the phenotype of psychosis (while also recognizing that psychosis is closely related to magic and religion).
Cultural factors undoubtedly play a prominent role in creating the institution of shamanism, and it certainly is possible that such an identifiable social role would inevitably attract non-psychotic practitioners; however, it also cannot be discounted that there is an anthropological literature replete with examples of psychotic-like behaviours in the personal histories of shamans (Ackerknecht Reference Ackerknecht1943; Devereux Reference Devereux1961a; Laubscher Reference Laubscher1937).
Over the years, I have learned that two common misconceptions prevent experts from appreciating a connection between psychosis and shamanism. The first is a failure to recognize that the majority of psychotic individuals do not live in a persistently disorganized mental state (this was true even before the advent of effective treatments). This means that most individuals with a psychotic disorder (e.g., schizophrenia, bipolar disorder) would have been capable of being shamans, most of the time. In any Gaussian distribution of phenotypic traits, the extremes do not typically represent the most adaptive phenotype. Similarly, the most grossly psychotic individuals would not necessarily have been shamans. However, when one combines the frequency of schizophrenia, schizotypal personality disorder (i.e., a milder form of schizophrenia), and bipolar spectrum disorders, a non-trivial frequency of aspirant shamans is produced (approaching 5%–10% of the general population). It is precisely this cluster of heritable diagnoses that have a special affinity for magico-religious discourse, as evident in their historical participation in cults, paranormal beliefs, possession states, and spiritual hallucinogenic use – social phenomena considered to be at the outskirts of both religion and psychosis. Accordingly, the eighteenth-century “epidemic” of schizophrenia was probably caused by a convergence of societal changes (i.e., secularization, industrialization, and greater government accountability), which intensified the disabling aspects of psychosis.
The second misconception around shamanism is an underappreciation for the similarity of the cognitive substructure of psychosis to basic religious ideation. According to cognitive theorist Pascal Boyer, a religious idea must incorporate a fact that specifically contradicts at least one defining characteristic of an ontological category (Boyer Reference Boyer2001). For example, a ghost may have the form of a person, but it lacks one essential quality (i.e., physical matter) integral to its ontological category (i.e., persons). Research studies consistently have found that about 60% of delusions and hallucinations contain outright religious themes (Rudaleviciene et al. Reference Rudaleviciene, Stompe, Narbekovas, Raskauskiene and Bunevicius2008). If one broadens the definition of religiosity and tallies magico-religious themes, however, the frequency turns out to be much higher. For example, our research team observed that 25 of 26 patients with schizophrenia possessed plausible magico-religious themes inside of their delusions and hallucinations (Polimeni Reference Polimeni2012, p. 191).
The target article concludes that shamanism is evolutionary “cheesecake,” but there are several compelling reasons to believe that the shamanistic phenotype is not a zero-sum game. One problem in the evolutionary study of behaviors is that there is often a failure to separate incidental actions from evolutionary effective activities. For example, not every manifestation of anger is evolutionarily advantageous, but, on average, the sum total of angry expressions provides phenotypic advantage. Similarly, not every shamanistic endeavor would have necessarily been evolutionarily advantageous. My own view is that some of the more sporadic shamanistic activities may have been more evolutionarily impactful (i.e., divining, out-group suspiciousness) compared with some of the more conspicuous shamanistic practices (spiritual healing, weather prophesies), which may simply have been incidental behaviors tolerated by evolutionary processes. Another notable feature of shamanism is trance, which has been neglected in most theories about shamanism, but skillfully examined in the target article.
One interesting idea in the target article is framing shamanism as one of the oldest professions; however, I propose that the better characterization – in keeping with ethological principles – is task specialization (similar to task specialists of eusocial insects) (Polimeni & Reiss Reference Polimeni and Reiss2002). It is noteworthy that two genetic mechanisms theoretically able to support task specialization (i.e., heterozygote advantage and assortative mating) also may be relevant in the heritability of schizophrenia (Polimeni Reference Polimeni2012).
Where schizophrenia is common, shamans are not; and where shamans practice, insanity becomes spiritual. The distinguished evolutionary psychiatrist John Price has argued that many of the evolutionary advantages of prehistoric religions are specifically dependent on contact with the gods being restricted to a sole individual (Stevens & Price Reference Stevens and Price2000). Hunting and gathering societies are often forced to make arbitrary (i.e., random) decisions (e.g., when to plant crops, which new direction to hunt, if and when to attack or flee another group); having a sense that the gods are backing one choice puts the entire tribe on the same page, working together. The evolution of shamanism is indeed complex, and the target article capably examines some of the cultural aspects maintaining the institution of shamanism; however, it arguably misses the spark that gets the whole process going – the occurrence of intrusive psychotic experiences (containing magico-religious themes) in those individuals typically destined to be shamans.