Doing my own independent research, I've noticed a clear pattern of religious people reporting feelings and sensations that they usually describe with expressions such as "waves of electricity", "fire", "heat", "burning all over", among others. I've heard expressions like these mainly from individuals in Pentecostal and Charismatic circles.
For illustrative purposes, here are some example video clips from individuals describing their first-hand experiences: A, B, C, D, E, F, G, H, I, J, K, L, M.
Also, here is a quote from a very descriptive testimonial posted on Charisma Magazine:
[...] In an instant, the Spirit of God gave me a single word in tongues to speak out, and as I repeated it, more words erupted through me. The power of the wonderful Holy Spirit enveloped me as what seemed like waves of electricity and what I can only describe as God's love and power washed over me. It seemed as though a spotlight exploded out of my mouth as I spoke in tongues, with my arms and hands surging with tremendous currents of electricity as the waves of power washed over the rest of my body as I loudly spoke in tongues, feeling immersed in His Spirit. [...]
Source: https://www.charismamag.com/spirit/revival/32085-this-is-what-it-looks-like-when-holy-spirit-s-electric-power-sweeps-over-you (cached version)
Reviewing literature about these experiences in Google Scholar, I came across a paper published in 2014 by Julia L. Cassaniti and Tanya Marie Luhrmann titled The Cultural Kindling of Spiritual Experiences (https://doi.org/10.1086/677881). In this paper, there is a very interesting claim made by the authors. Here are two quotes:
The “Holy Spirit” experience, for example, is a concept often used to describe an event in which someone feelings an intense surge of power sweeping through their body like electricity, or what we would call the bodily affordance of an adrenaline rush.
These three phenomena—cataplexy, or the loss of muscle control; adrenaline surge, as if electricity is shooting through the body; and emotional surge, when someone experiences intense, overwhelming emotion—are examples of physiological phenomena that are common to all human bodies but unusual enough so that people can remember the moment independent of a specific label.
In other words, these authors are essentially claiming that the overwhelming feelings reported by religious individuals, typically described with expressions such as "waves of electricity", "power", "fire", "heat", "burning all over", etc., would be nothing but physiological symptoms produced by sudden and intense surges of the adrenaline hormone released into the individuals' bloodstreams. However, the paper offers no evidence to justify this claim. Moreover, a quick research into adrenaline rushes shows that they play a big part of the body's fight-or-flight response, which is an evolutionary adaptation that gets triggered by situations that we perceive as dangerous, such as horror movies, extreme sports and similar, which to my layman understanding would make no sense in a typical religious worship setting.
So, is it factually correct that adrenaline rushes are the ultimate cause behind the dramatic spiritual experiences reported by individuals in Pentecostal and Charismatic circles?
@TonyMobbs in the comment section suggests that this question has already been answered here. Concretely, he is pointing to two hypotheses from his answer: H4) Conformance to the social norms and H8) Attention seeking (as the other hypotheses are dismissed in the same answer). I don't agree with his suggestion, for the following reasons:
- H4 was proposed as an explanation for the outer behaviour of shaking/trembling, not for the feelings of electricity, fire or heat reported by people. H4 basically proposes peer pressure as the primary incentive for shaking and trembling, and someone who intentionally fakes shaking or trembling out of peer pressure emotion-wise would feel feelings of relief, calm or social acceptance at best (not waves of "electricity", "fire" or "heat").
- H8 (attention seeking) was later on proposed after I presented counter-examples to H4 in a chat room discussion. However, at the moment H8 is just a placehoder in his answer, its writing is still pending, and at no moment his answer explains how H8 can account for feelings of "electricity", "fire" or "heat".