Nightmares and nocturnal attacks have been closely connected
to myths and monsters across time and cultures. It has even been
even suggested that the night-mare is the origin of all mythology
(see Kirby, 1901). Although few modern scholars would be quite
so bold or sweeping in their claims the pervasiveness of the
nocturnal attack in mythology, religion, and legend is quite
striking. Ardat lili or Lilitu, an evil Sumerian spirit, is one
of the earliest Hag-demons. She was capable of flying, which
she preferred to do at night, at which time she frequently attacked
men in their sleep. She is thought to constitute the prototype
for the Hebrew Lilith and the Roman Lamia (Russell, 1995). All
these female spirits or demons have in common an association
with nocturnal attacks. Moreover there are a number of related
spirits described in Middle Eastern and European lore with connotations
of leaping upon, oppressing, or crushing, supine individuals
as they attempt to sleep at night. Some of the better-known spirits
of this sort are; Greek ephialtes (one who leaps upon) and mora
(the night "mare" or monster, ogre, spirit, etc.), Roman incubus
(one who presses or crushes), German mar/mare, nachtmahr, Hexendrücken
(witch pressing), and Alpdruck (elf pressure); Czech muera, Polish
zmora, Russian Kikimora, French cauchmar (trampling ogre), Old
English maere (mab, mair, mare-hag), hagge, (evil spirit or the
night-mare--also hegge, haegtesse, haehtisse, haegte); Old Norse
mara, Old Irish mar/more, Newfoundland Ag Rog (Old Hag), and the
Spanish pesadilla ( Keissling, 1977; Hufford, 1982; OED, Roscher,
1900/1979; Sebald, 1978; Thompson, 1957; Ward, 1981). In addition,
the Greeks also had the pnigalion (the choker) and the barychnas
(the heavy breather)troubling would-be sleepers (Keissling, 1977).
In addition to attacking helpless humans at night these creatures
were shape-shifters, able to take on various forms during these
attacks (Keissling, 1977).
Among the writers of European antiquity, Herodotus provides an early account of an ephialtes who appeared to the wife of King Ariston of Sparta in the form of the King himself, although it was itself the spirit of the deceased hero Astrobacus. Horace makes a reference to a threat whereby a boy claims that if he is killed he "will attend you as a nocturnal fury; and, a ghost, I will attack your faces with my hooked talons (for such is the power of those divines, the Manes), and brooding upon your restless breasts, I will deprive you of repose by terror." In Greece and Rome, the ephialtes and the incubus were identified with gods and demons of the forest and woodland, such as, the god Pan (Roman = Faunus), as well as Satyrs, Sirens, and Silvani (Kiessling, 1977), and even with the goddess Diana (Russell, 1995). Many of these creatures were depicted as resembling humans in the upper portions of their bodies and beasts, usually goats or fauns, in the lower extremities. This association was evidently still quite strong by the time of Augustine who explicitly associated Pan with the incubus. Pan was particularly associated with shepherds and goatherds and one may well imagine that the isolated and rigorous life of such individuals predisposed them to many nocturnal visitations. Similarly, the succubus Lilith was to be typically to be found in the remote regions of the desert (Isaiah, 34:12). Pan's attacks were of course associated with panic. Pan was also more generally seen as the instigator of "dreams and visions, especially those that produced sudden, violent terror" (Kiessling, 1977, p. 5).
There is also certain classes of angels, "watchers" and "fallen angels," referred to in the Judeo-Christian traditions, associated with the incubus. Some were sent to watch over humans, and sometimes became enamoured of human women. The progeny of such encounters were, however, monsters and demons who further molested and assaulted helpless sleepers (Kiessling, 1977). Augustine doubted that angels were the source of incubi, though he had no doubt that the latter existed. "There is, too, a very general rumor, which many have verified by their own experience, or which trustworthy persons who have heard the experience of others corroborate, that sylvans and fauns, who are commonly called "incubi," had often made wicked assaults upon women, and satisfied their lust upon them; and that certain devils, called Duses by the Gauls, are constantly attempting and effecting this impurity is so generally affirmed, that it were impudent to deny it" (ch. 23). Martin Luther was unequivocal in asserting that, "sunt incubi et succubi daemonis . . ."
In some traditions these monsters are the descendents of Adam and his first wife, none other than Lilith herself (Kiesling, 1977). Certain midrashic stories allege that Cain is an offspring of such a union, in this case between Eve and the ultimate fallen angel, the devil himself. It is not surprising, therefore, that Beowulf's foe, the monster Grendel (referred to at least once n that famous poem by the term maere--Kiessling, 1977) is described in the poem as a descendent of Cain. Grendel, a cannibalistic devourer of men invariably carries out his attacks in the dead of night on sleeping men. Prior to Beowulf's confrontation with Grendel, Hrothgar tells him how previous heroes have been defeated, apparently because they were unable to remain awake. It is also worth noting that Beowulf eschews arming himself for the confrontation with Grendal on the grounds that Grendel does not bear arms. He destroys Grendal as Grendal destroyed men, by ripping a limb from its socket.
These experiences and their ensuing personification and elaboration are by no means limited to western culture. In St. Lucia, West Indies, an attack of kokma comes at a time that the individual is just falling asleep or just waking up. The sensations include pressure on the chest, inability to move, and anxiety. The kokma is the spirit of a dead baby that haunts an area, attacking people in their beds. In a familiar pattern, they jump on the victim's chest and clutch at the throat. The victim attempts to cry out, or in some other way to get another's attention, someone that might scare off the kokma. Informants described the babies clutching at their throats. The notion that the attacks are thought to be initiated by dead, unbaptized babies is also found in Ireland. "The kokma cannot be controlled, they grab people just for the hell of it" (Dressler, 1977, cited in Ness, 1978). In Thailand experiences referred to as Phi um (ghost covered) and phi kau (ghost possessed) involve pressure, immobility, and something black covering the body. In Japan kanashibara ("to tie with an iron rope") is a common and widely known experience (Fukuda, 1993). In Korea, people are afflicted by ka wi nulita ("scissors pressed"), an experience felt to be brought on by fear. In the Far North one speaks of agumangia (Inupik) or ukomiarik (Yupik) in which "a soul" tries to take possession of the paralyzed victim. In Laos, (Lemoine & Mounge, 1983) da chor is described as follows: "You want to listen, you can't hear; you want to speak, you are dumb; you want to call out, you cannot; you feel you are dying, dying; you want to run away. You piss with fear in your sleep" (cited in Firestone, 1985, p. 61). In the Philippines people are afflicted with urum, ngarat (Simons & Hughes, 1985). Among the Hmong of Laos the nightmare spirit is referred to as dab (nightmare) tsog (evil spirit) or tsog tsuam (evil spirit who crushes, smothers, or presses upon) (Adler, 1994).
As Hufford (1976) noted almost a quarter-century ago, of the SP night-mare, " (1) the experience is wide-spread, at least in Western culture; (2) it has been regularly reported for more than two thousand years; (3) it has been attached to a variety of narrative frameworks . . . , but regardless of the framework, the experiential features have remained basically the same; (4) this consistency of detail, apparently rather independent of tradition, is the most surprising and difficult to account for" (p. 78). These experiences appear to be widely known in traditional cultures, in marked contrast to industrialized society. Hufford (1976) found that, among his Newfoundland participants who had been hagged, half did not know the Old Hag tradition. This is the same proportion of the entire sample who had not heard of the tradition. This, of course, quite inconsistent with the cultural source hypothesis that such experiences are induced by knowledge of cultural traditions. Subsequent research has made clear that these experiences are by no means limited to Western cultures. Also striking in this connection is the similarity of the descriptions of the SP experiences across all cultures, including industrialized culture which appears to have no commonly accepted popular myths to offer cognitive support to the experiences. Hufford (1976) makes a fairly convincing connection between sleep paralysis and "bedroom" alien abductions as described by Keel (1970). Many others have made this connection since (Baker, 1994, Blackmore, 1998; Spanos, 1994).