The target article is an ambitious attempt to layer a cultural-evolutionary framework on the phenomenon of shamanism. Within it, shamans – identified by their use of trance practices – are a product of widespread beliefs that uncontrollable environmental outcomes are influenced by supernatural agencies. Singh also suggests that competition among professionalized shamans begets selective pressure for the most efficacious-appearing shamanistic techniques, as dictated by cognitive heuristics and biases.

Cultural evolution is not the same as biological evolution, though we can use certain criteria from the latter as informative heuristics of the former. When assessing the framework offered from such an evolutionary perspective, however, the model provided frequently jumps among levels of analyses, discussing the phenomenon of shamanism as a cultural institution, selection pressures among shamanistic techniques, and individual cognitive biases. Although we recognize Singh's ambitious efforts to provide a multilevel framework, this does not remove the need for better demarcation of the processes and pressures operating at each level. In particular, we were left with many critical questions concerning why, within shamanism, trance occupies such a privileged transformative role. What makes trance more effective than other alternative ritual and cultural actions?

According to Singh, trance is a necessary feature of shamanism. Finding more precise definitions lacking, he opts for a more inclusive definition wherein trance is a temporary state characterized by a variety of unusual behaviors, with an equally varied set of culture-specific interpretations. Singh argues that what connects the diverse practices is the ability of trance performances to serve as “dramas of strangeness,” which act as markers of non-normality. Here, however, we run into an issue of circular logic: Labeling the effectiveness of trance performances to signal transformation as their core defining characteristic fails to explain why trance performances are particularly effective at this.

This is problematic, particularly when many alternative rituals seem to be equally capable of doing the epistemological heavy lifting Singh claims for trance. For example, weddings and initiations transform people, baptisms signify rebirth, and ascetic practices, such as fire-walking rituals (Xygalatas Reference Xygalatas2014), demonstrate abnormal levels of tolerance. Rituals, in general, do much of the other work of the shaman: They can manage uncertain outcomes effectively (Rudski Reference Rudski2001), alleviate anxiety associated with a lack of control (Norton & Gino Reference Norton and Gino2014), and imbue objects with special significance (Kapitány & Nielsen Reference Kapitány and Nielsen2015, Reference Kapitány and Nielsen2016), all while serving as markers of identity (Sosis et al. Reference Sosis, Kress and Boster2007) and commitment (Irons 2001). Singh acknowledges that the possession of physical oddities and the performance of initiations and ascetic practices also serve as potent indicators of transformation. This leaves us with the question, though: What then separates such actions from the trance category in Singh's model? Is it just another name for dramatic rituals?

With rituals, the mechanisms of action are increasingly well understood:

For trance to qualify as a cultural adaptation independent of ritual, it needs a far more nuanced and dissociable mechanism – particularly in light of the fact that rituals seem equally qualified for solving the stated evolutionary problem.

If trance is unique, it may rest on a point from which Singh is keen to distance his theory – namely that, although trances are diverse in form, they almost invariably involve some form of disruption to ordinary conscious processes, be it from communicating with or channeling some foreign consciousness, or the extension (or diminishing) of the practitioners' ordinary mentalities. We agree with Singh's criticism of theories that advocate a common neurophysiological experience or an “integrative mode of consciousness” as the common element of trance. One need not endorse such positions, however, to recognize the key role that mentality, and violations thereof, plays in the diverse array of trance practices, particularly among observers who generate the selective pressure on persuasive shamanistic techniques.

We suggest that this emphasis on mentality and violation of ordinary mental boundaries represents the core distinguishing feature of trance practices and why they occupy their privileged position within shamanism. Individuals across cultures display an early developing interest in their social worlds (Spelke et al. Reference Spelke, Bernier, Skerry, Banaji and Gelman2013) and follow a similar trajectory in their development of reasoning about others' minds (Liu et al. Reference Liu, Wellman, Tardif and Sabbagh2008; Wellman et al. Reference Wellman, Cross and Watson2001). Humans everywhere are quick to attribute agency to ambiguous events (Csibra Reference Csibra2008; Hamlin Reference Hamlin, Kiley Hamlin and Baron2014) and to detect patterns and teleological purpose in nature (Kelemen Reference Kelemen1999a; Reference Kelemen1999b). Similarly, there is strong evidence that humans are intuitive dualists (Bloom Reference Bloom2004) who dissociate mental and physical processes, readily attributing mentality to the dead (Bering Reference Bering2006; Bering & Bjorklund Reference Bering and Bjorklund2004; Huang et al. Reference Huang, Cheng and Zhu2013).

Collectively, these tendencies represent a fertile, cross-culturally recurrent foundation that, at least partially, could account for the level of interest that surrounds individuals demonstrating unusual mental abilities and the ability to interact with unseen agents and mental forces. (For an illustration of such an approach applied to spirit possession, see Cohen [Reference Cohen2007].) The theory that minimally counterintuitive concepts are especially memorable is subject to ongoing debate (Purzycki & Willard Reference Purzycki and Willard2015); however, the basic insight that people attend to things that possess some striking features but otherwise accord to intuitive expectations seems well supported (Banerjee et al. Reference Banerjee, Haque and Spelke2013; Boyer Reference Boyer2001).

Our suggestion for the reasons trance should be privileged, the ways it might work above and beyond other ritual practices, and the extent to which shamans accord or contradict intuitions about mentality is admittedly speculative. Whether or not Singh agrees with our suggestion, however, a more functional definition and clearer set of trance-related hypotheses are warranted and can only improve his framework's coherence and explanatory power.