Contents lists available at ScienceDirect Medical Hypotheses journal homepage: www.elsevier.com/locate/mehy The near-death experience (NDE) as an inherited predisposition: Possible genetic, epigenetic, neural and symbolic mechanisms James Lake Center for Integrative Medicine, University of Arizona College of Medicine, Tucson, AZ, United States The argument in overview The paper is divided into four parts. In Part I, I review principle NDE models, important recent research findings and limitations of NDE re- search I remark on the absence of consensus on an explanatory model of NDEs. Part II begins with an overview of NDE evolutionary thinking up until now. I define an NDE predisposition as a specialized kind of higher cognitive trait and argue that this predisposition probably originated from a pre-adaptation that permitted early hominins to have self-re- flective awareness and experience specialized states of consciousness involving complex mental imagery ensuring flexible adaptive responses to unpredictable or life-threatening situations. I argue that a model of evolutionary dynamics underlying an NDE predisposition must be contextualized in a more general theory that views body-brain-en- vironment as a dynamic complex system influenced by biological, psychological and symbolic processes. I describe evolutionary scenarios that may have led to the origin and persistence of an NDE predisposi- tion in populations through direct, indirect or neutral selection invol- ving both biological and nonbiological inheritance mechanisms. Specifically, I examine the evolutionary dynamics of an NDE predis- position from the perspectives of multi-factorial fitness landscapes, the neuronal replicator hypothesis, socio-cultural, behavioral and symbolic inheritance systems. I contrast NDEs reported in the context of life- threatening situations to phenomenologically similar experiences that frequently take place in non-life-threatening contexts such as dreams and in trance. I examine claims of spiritual and psychological changes following both pleasant and frightening NDEs in the context of different evolutionary scenarios. In Part III I discuss possible neural mechanisms underlying evolutionary dynamics of an NDE predisposition. Topics covered include heritable modules that solve problems related to sur- vival, implications of functional integration of the limbic system and neocortex, the concept of brain-to-brain replication of semantic in- formation as a pre-adaptation required for socio-cultural transmission of NDE narratives as memes, and the possible roles of epigenetic me- chanisms in shaping the inheritance and transmission of an NDE pre- disposition. In Part IV I critique the various evolutionary scenarios discussed in the paper and argue that an NDE predisposition probably originated and persists through the operation of multi-factorial biological, social and symbolic processes that shape inheritance. I argue that an NDE predisposition could have resulted from direct or indirect selection or both direct and indirect selection depending on factors that shape evolutionary dynamics of different populations at different times. Finally, I make recommendations for improvements in methodology in near-death research broadly, and propose field studies that may clarify the relative contributions of genetic, epigenetic and social mechanisms influencing the evolutionary dynamics of an NDE predisposition. Part I: background Principle NDE models and recent research Near-death experiences (NDE) have been characterized as “unusual, often vivid and realistic, sometimes profound life-changing experiences reported by people who have been either physiologically close to death, as in cardiac arrest or other life-threatening medical conditions or emergencies, or by people who believed that death was imminent [27,36].” NDE features vary significantly between individuals in ways that may be context-dependent (see below) hence there is no proto- typical or core NDE. However, studies consistently report four recurring features: out-of-body experiences, ‘seeing a bright light,’‘encountering entities,’ and ‘feelings of peace [48].’ Individuals who have NDEs fre- quently report significant changes in values and beliefs, including in- creased spirituality, greater concern for others, a heightened sense of purpose and appreciation of life, and decreased fear of death [55,64,74]. It is important to note that not all NDEs are pleasant and some experiences are described as ‘nightmarish’ or ‘hellish’ however unpleasant NDEs are probably less common than pleasant NDEs. Esti- mates of the incidence of NDEs in the general population range from 9 to 18% [30,34]. Findings of a small retrospective study suggest that as many as 26% of individuals who are hospitalized following a suicide attempt have NDEs [82]. The paucity of evidence that NDEs take place in the actual moments of trauma or anticipated trauma, has led some writers to argue that at least some NDE features can be adequately explained on the basis of “retrospective imaginative reconstruction” of perceptions that take place when the brain is unconscious; memories of objects or events that may have been perceived just before losing consciousness or just after https://doi.org/10.1016/j.mehy.2019.03.016 Received 22 January 2019; Accepted 21 March 2019 E-mail address: contact@integrativementalhealth.net. Medical Hypotheses 126 (2019) 135–148 0306-9877/ © 2019 Published by Elsevier Ltd. T