The ritualised mind alteration hypothesis of the origins and evolution of the symbolic human mind By TOM FROESE (This is a pre-print of an article currently in press in Rock Art Research that is expected to appear in volume 32 in 2015). Introduction This article was originally motivated by a couple of critical commentaries about my work (Helvenston 2014, and above). However, I quickly came to realise that, to be able to adequately respond to the specific concerns that were raised, I would have to present some general considerations. It is only with this context in place that it becomes clear why I think that these details are worth arguing over in the first place. Thus, before anything else, the overarching question is: when it comes to the formidable task of understanding human pre-History, why should we care about altered states of consciousness? To some extent, intentional alterations of normal waking consciousness are so widely prevalent in today’s world that it is difficult to think why they should not have previously played a role. Throughout Historic times mind alteration has been achieved by an incredible variety of means, be it with the consumption of coffee, beer, tobacco or some stronger substance, or by practising a specialised mind-body technique of mind alteration such as yoga, meditation or repetitive chanting. At this point the precise method used is not as important as the general insight that every notable culture has its own ways of changing consciousness from the normal waking state, with some methods being more potent in their alterations than others. Surely in itself this seemingly universal phenomenon of mind alteration is in need of a scientific explanation. But, and this is where things get more controversial, how far back into pre-History do such practices go? Every major ancient culture also seems to have had its preferred substances to alter waking consciousness in one way or another. The variety of psychoactive plants and the diversity of their cultural contexts is truly staggering (Rätsch 2005; Schultes et al. 2001). To cite just a few more recent studies, such practices are known for ancient Eurasia (Guerra-Doce in press; Jiang et al. 2006, 2009; Merlin 2003), Australia (Dobkin de Rios and Stachalek 1999), Mesoamerica (De La Garza 2012; Guzmán 2008; Viesca Treviño et al. 1996), South America (Blanc 2010; Luna 2013; Torres 1996), Africa (Marcus 2009; Sobiecki 2008), and North America (Charlton 2004; Crown et al. 2012; Litzinger 1981; Winter 2000). And with improving methods in archaeochemical and archaeobotanical research we can expect that our knowledge of the list of plants used to modulate the mind and their ancient distribution of usage will increase (e.g. Bawaya 2014; Guerra-Doce in press). Certainly, the widespread popularity of many substances is explainable in terms of their evident functions in daily life, such as increasing physical energy and wakefulness (coffee, tea, coca, cacao etc.) or decreasing inhibition (e.g. alcohol and aphrodisiacs). But there are several categories of plants, typically used in sacred rituals, which do not fit within this scheme because they interrupt the functions of daily life. Depending on the type of plant, these interruptions can range from mild changes in mentation and enhanced suggestibility, to strong perceptual changes, vivid hallucinations and full-blown deliriums (Díaz 2010). Although care must be taken not to conflate these types of plants, for our current purposes it is sufficient if we group them together as psychedelics. If we believe our current legislation system, such as the UN Convention on Psychotropic Substances, most psychedelics have no value and substantial potential for harm and abuse. If so, then it becomes difficult to explain their widespread use and it may seem plausible that people only became interested in them in more recent times, perhaps as a negative side-effect of the formation of complex societies. Yet the idea that use of psychedelics is a maladaptation occasioned by complex society is not consistent with the evidence. The first thing to note is that according to some leading drug experts, the desire to occasionally profoundly modify one’s state of mind is deeply inherent in human nature, perhaps even comparable to some of the other basic biological and innate drives (Siegel 2005; Weil 2004). What their assessment suggests is that we are not necessarily dealing with an exclusively cultural phenomenon at all. Indeed, there is a growing recognition that even a wide variety of nonhuman animals will intentionally and repeatedly intoxicate themselves when given the opportunity to do so (Samorini 2002; Siegel 2005). For one well-accepted example we only need to think of cats’ obsession with plants that are commonly known as catnip (e.g. the genus Nepeta), which can temporarily cause profound alterations of their behaviour. Adaptive benefits of altered states of consciousness Yet if it turns out that such mind alteration is prevalent in the rest of the animal kingdom, then this presents us with another puzzle. Are we dealing with another unfortunate mismatch between animal brains and their botanical environments that evolution by natural selection has been unable to remove from populations? Or could there even be selective advantages conferred by this seemingly unusual behaviour? The idea of pure coincidence can be ruled out by taking a closer look at the chemical substances and neurotransmitter receptors that are involved in the effects of psychoactive plants. On the contrary, the highly specific ways in which these plant substances interfere with animal neurotransmitters is suggestive of a co-evolutionary relationship that is millions of years old. And while part of the explanation is that plants evolved a defensive reaction against animal predation, there is another side to this story. Sullivan and Hagen (2002) have argued that consumption of psychedelic plant chemicals could have conferred selective benefits, for example because they could be exploited as externally produced substitutes for metabolically costly endogenous neurotransmitters. Nevertheless, since Sullivan and Hagen’s explanation is situated only at the level of metabolism and neurophysiology, it leaves the role of the profound psychological effects rather mysterious. Could mind alteration in itself not also have some selective benefits? At least this is suggested by the positive relationship between altered states of consciousness and