We have probably all said at some point in our lives that something nearly scared us to death. A roller coaster, a haunted house, a near-missed traffic accident, a sensitive text that was sent to the wrong person, an exam that we had somehow forgotten—our lives seem to be filled with stressful experiences. If you think about the phrase scared to death, however, it is interesting to consider that our emotional response could reach such an extreme level, resulting in a person’s demise.
In 1942, Walter Cannon, a biopsychology pioneer who introduced the “fight-or-flight” function of the sympathetic nervous system, explored the potential explanation of claims that people throughout history had been frightened to death. For this project, he consulted historical accounts of case studies in which a person had died for no apparent medical reason after being frightened. He read 16th-century accounts of people in South Africa who were condemned to death by “medicine men” for committing some tribal indiscretion. He also reported the case of an African tribe member who was on a journey and stopped by a friend’s home for a meal. The meal was chicken, and the traveler knew that he could eat only domestic hens; the traveler was forbidden to eat wild hens. However, the host denied that the chicken being served was wild, and the traveler enjoyed the meal. Several years later, the two men met again. This time, the previous host confessed to having served his friend, the African tribe member, the forbidden wild chicken. At that point, the African tribe member started trembling with fear and, within 24 hours, was dead (Cannon, 1942).
Cannon argued that the many cases he had presented were a result of the person believing that he or she was condemned to death because of a voodoo curse, consumption of a taboo food, or some other form of condemnation. Cannon referred to this phenomenon as voodoo death. More recently, the neurologist Martin Samuels has pointed out that many contemporary examples exist of people being frightened to death. For example, a minister in Boston was reading his Bible quietly at home when police officers mistakenly raided his dwelling. In the midst of all the excitement, this minister collapsed in shock and was found to have died of a heart attack (Das, 2006; Samuels, 2007).
Behind the Scenes
In his initial analysis, Cannon hypothesized that voodoo death stemmed from persistent and extreme activation of the sympathetic nervous system. Thus, the adrenaline release, resulting from the “cursed” victim’s perceived lack of control and impending doom, overstimulated the cardiovascular system in a fashion similar to that of an overdose of cocaine. In the 1950s, another biopsychology pioneer, Curt Richter, expressed a different view. He proposed that the complementary arm of the autonomic nervous system, the parasympathetic nervous system (which is typically activated following the activation of the sympathetic nervous system), responds excessively, thereby calming the person to death. Richter arrived at this conclusion after observing that laboratory rats could survive extended swimming sessions when there was no escape route. By contrast, if the rats had to face this situation with freshly trimmed whiskers, depriving them of sensory feedback, they would drown, likely because of heart failure (Richter, 1957).
Such studies would not be approved by institutional review boards today because of strict ethical guidelines, but the findings are still informative. Perhaps the disoriented whiskerless rats saw no escape from the stressful situation, similar to a human under a curse from a respected source. After discovering that the surgical removal of the adrenal gland—a technique called an adrenalectomy—failed to protect the stressed swimming rats from death, Richter concluded that their death was not caused by the overexcitation of the sympathetic nervous system, but by the overstimulation of the parasympathetic nervous system. Or, more specifically, it was caused by increased vagal tone, inhibition of heart rate resulting from stimulation of the vagus nerve (Samuels, 2007).
Which biopsychology pioneer was correct? Samuels has suggested that both the sympathetic and the parasympathetic arms of the autonomic nervous system are likely involved, meaning that both men were partially correct. Certain systems likely predominate at different times, with the sympathetic nervous system having a greater influence earlier in the process and the parasympathetic nervous system controlling the later events. After investigating the autopsied hearts of more contemporary human case studies, Samuels also observed cardiac lesions that could lead to heart failure. Systematic studies with mice suggest that sympathetic activation, even in animals whose adrenal glands had been removed, leads to the cardiac lesions. Thus, the lesions may be a result of direct interactions between the nervous system and the heart, rather than a result of the release of stress hormones (Hawkins & Clower, 1971).
Because we will never study individuals experiencing life-threatening fear in the laboratory, much of this research depends on case studies and archived evidence (as is the case in true mysteries!). However, this nontraditional source of data has convinced Martin Samuels, also known as “Dr. Death,” to continue to explore the effects of neurogenic, or voodoo, death. This research has led him to propose that we are all susceptible to being frightened to death if the fear factor is high enough and there is no perceived escape from the impending doom (Das, 2006; Samuels, 2007).