Do curses work?
Belief in malignant supernatural forces causing illness or misfortune is a common tradition in cultures around the world. The concept of "black magic", the "evil eye", curses, witchcraft, bringing down disaster on unwitting victims has inspired a host of ritual practices designed to protect users from harm. My mother, bless her heart, has an all-purpose prayer that she uses to protect family members against the mal occhio (evil eye). Passed down in her family for generations, the prayer can only be taught at the stroke of midnight on Christmas Eve. While such beliefs seem harmless enough, fear of malignant cursing has inspired horrendous episodes of anti-witch hysteria through the centuries (and still does today).
But is is actually possible for belief in curses to kill victims? In a now-classic paper titled "Voodoo Death", physiologist Walter Cannon (of Cannon-Bard hypothesis fame) explored that very question. First published in 1944 in American Anthropologist, Cannon coined the term "voodoo death" to describe the phenomenon of sudden death brought about by emotional shock, especially fear. Citing numerous examples from anthropological literature, Cannon presented a series of case histories including deaths occurring among Brazilian tribesmen after being cursed by local "medicine men". One memorable citation from Arthur Glyn Leonard's classic book on the lower Niger described the phenomenon in action:
I have seen more than one hardened old Haussa soldier dying steadily and by inches because he believed himself to be bewitched; no nourishment or medicines that were given to him had the slightest effect either to check the mischief or to improve his condition in any way, and nothing was able to divert him from a fate which he considered inevitable. In the same way, and under very similar conditions, I have seen Kru-men and others die in spite of every effort that was made to save them, simply because they had made up their minds, not (as we thought at the time) to die, but that being in the clutch of malignant demons they were bound to die.
Being cursed was often the result of violating various cultural taboos or otherwise incurring the wrath of tribal chiefs or shamans. The means by which a curse could be laid could vary from simply applying the "evil eye" to formal rituals such as the use of "pointing-bones" among Australian Aborigines. Cannon also raised the possibility of chiefs or sorcerers reinforcing their reputation for laying curses through the discreet use of poison. Given the herblore available to many traditional shamans, this is not particularly farfetched although many of the cases that Cannon discussed involved curse victims wasting away even when poison or other medical explanations were ruled out. Even in those cases where an autopsy was performed on the curse victim, no clear medical cause for death could be found (except for the curse victims who wasted away from refusing to eat or drink).
For victims in the final stage of their illness, only the timely intervention of the sorcerer or shaman lifting the curse could save them from death. Shamans persuaded to lift their cause often use an elaborate ritual and, in many cases, presented the victim with a visual "proof" of the curse being lifted (usually in the presence of the victim's family to impress them with his/her power). Once the crisis is passed, recovery is usually rapid and complete. The involvement of the victim's extended social network seems to be the key in many of the cases that Cannon reported. Those victims who are cursed typically lose all support as family and friends distance themselves. Once ostracized, the curse victim becomes a pariah with no real options besides death or exile. "Shunning" of curse victims, often perceived as being responsible for their own predicament, is an effective weapon to reinforce the power of the shaman who laid the curse. Since being part of the greater tribal community remains the cornerstone of the individual's existence in many societies, it's hardly surprising that the loneliness that can result from being cursed can be so deadly.
But is there a physical basis for "voodoo death"? Again, Cannon outlined some common characteristics in the cases that he discussed. The effect that extreme fear and anger can have on the body is well-documented. Cannon reviewed the "fight or flight" reaction and the opposing roles of the sympathetic and parasympathetic nervous systems in preparing us to deal with crises. Arousal of the sympathetic nervous system results in pupil dilation, rapid heart rate, increased lung capacity and respiration, inhibition of digestion, shaking, sweating, and other autonomic responses. Essentially, the body is prepared for action. If that action is delayed or if we are unable to respond to the stressful situation in a timely fashion however, we experience exhaustion and become vulnerable as a result. As Cannon himself states:
All these changes render the animal more efficient in physical struggle, for they supply essential conditions for continuous action of laboring muscles. Since they occur in association with the strong emotions, rage and fear, they can reasonably be interpreted as preparatory for the intense struggle which the instincts to attack or to escape may involve. If these powerful motions prevail, and the bodily forces are fully mobilized for action, and if this state of extreme perturbation continues in uncontrolled possession of the organism for a considerable period, without the occurrence of action, dire results may ensue
Cannon also described research on sham rage produced in decorticated laboratory animals following intense stimulation of the sympathetic-adrenal system. The rage leads to rapid sweating, rapid heartbeat, heightened emotionality, and motor activity. Even when the animal appears visibly calm afterward, death can result after a few hours due to exhaustion. Sham rage has also been observed in humans, especially in cases involving damage to the temporal lobe and associated limbic system structures. Along with other physiological effects of sham rage, large amounts of adrenaline are also produced. Prolonged adrenaline release may lead to persistent constriction of the blood vessels which, in turn, leads to reduce blood volume and inadequate blood supply to the body's organs. Catastrophically reduced blood pressure, in conjunction with reduced food or fluid intake, can be linked to many of the reported voodoo deaths in the medical literature.
It is probably not surprising that sudden death has also been observed in cases involving severe shock. Even when other medical causes have been ruled out, death can still occur. Loss of appetite, sweating, rapid heartbeat, and other signs of autonomic distress can be important signals that the body is on the verge of exhausting its resources. Cannon described several examples of patients who died of apparently minor injuries following emotional trauma. While postmortem examinations may turn up evidence of brain hemorrhage, this is usually a consequence of the condition rather than a direct cause of death.
Ultimately, Cannon didn't attempt to provide a final explanation for why voodoo death occurs and simply suggested a hypothesis for researchers to explore. He also recommended that physicians monitoring potential cases watch for warning signs of shock including low blood pressure, rapid heartbeat, and perspiration. In (semi) tongue-in-cheek fashion, he ended his paper by saying:
If in the future, however, any observer has opportunity to see an instance of "voodoo death," it is to be hoped that he will conduct the simpler tests before the victim's last gasp.
While voodoo death cases relating to actual curses have become rare (although anti-witch hysteria is still going strong), research has confirmed many aspects of Cannon's ideas concerning the role of sympathetic arousal on the human body. In a reevaluation of Cannon's voodoo death paper, Esther Sternberg expanded Cannon's model by stressing the role of the hormonal system, particularly those hormones released by the pituitary and adrenal glands when the human body is confronted by stressors. These include catecholamines (unknown in Cannon's time) which open calcium channels, including in the heart muscle. She also discussed the role that the amygdala plays in mediating threat responses (she referred to this as the "vision-to-fear" or "auditory-to-fear" pathway depending on how the threat is perceived). In cases of abrupt shock, cardiac arrhythmia, chronic wasting, and disease can all occur when the body's own resources are exhausted.
Cases of sudden cardiac death linked to psychosomatic factors continue to be reported in the clinical literature, especially in patients suffering from preexisting conditions such as chronic depression or anxiety disorders. The complex relationship between cardiac arrhythmia and emotional stress often forms a "vicious circle" which is potentially deadly. Increased risk of cardiac failure has also been noted following natural disasters as survivors cope with the stress of dealing with loss. Although anthropologists still dispute Cannon's interpretation of existing cases (with some arguing that voodoo death should be considered a culture-bound syndrome), Walter Cannon's 1944 paper remains a classic in the field of psychosomatic medicine and psychophysiology and continues to inspire research into the role that emotional factors can affect the body.
So, can curses kill? You be the judge.