Hornell Hart, a professor of sociology at Duke University in North Carolina, collected together cases of what he called 'ESP projection' [Har54]. He required that the person not only have an OBE, but also acquire veridical information, as though from the OB location. This excludes many OBEs in which the information gained was wrong or could not be checked. He also rated the cases. The best possible case would gain a score of 1.0, but in fact the highest score given was .90. No higher scores were gained because the cases show a curious mixture of correct and incorrect vision which seems to be common in the OBE.
Through this research, one assumption is crucial, that ESP projection is a single phenomenon which might have any or all of Hart's eight features. Rogo [Rog78b] and Tart [Tar74a] have both suggested that several different types of experience may have been lumped together under the label 'OBE.' It could be that astral projection, traveling clairvoyance, and apparitions are quite different and need different interpretations, or other distinctions might be more relevant. The reason Hart gave why the non- evidential cases should be excluded is far from satisfactory: if there was no evidence of ESP they did not count in his analysis. Hart was ruling out the majority of cases on the basis of a very shaky criterion.
Perhaps the most thorough, and certainly the best-known case collection was carried out by Celia Green of the Institute of Psychophysical Research [Gre68a]. Her definition of an OBE was an experience, defined as follows, '... one in which the objects of perception are apparently organized in such a way that the observer seems to himself to be observing them from a point of view which is not coincident with his physical body.' J. C. Poynton [Poy75], like Green, advertised in the press, and circulated a questionnaire privately, and on the whole Poynton's results, although less detailed, are similar to Green's. Susan Blackmore [Bla82] has analyzed the cases collected by the SPR and by herself.
Table: Some Results of Case Collections [Bla82]
Green Poynton SPR cases Blackmore Proportion of 61% 56% 69% 47% 'single' cases Some features of 'single' cases: Saw own body 81% 80% 72% 71% Had second body 20% 75% -- 57% Definite sensation 'majority' 25% 36% -- on separation none Had connecting 4% 9% 8% -- cordApparently most people have had only one OBE, but the frequency of subjects claiming many OBEs is high enough to conclude that if a person has had one OBE he or she is more likely to have another. Also many people learn to control their OBEs to some extent, even if they never learn to induce them reliably at will.
OBEs are occurring in a variety of situations. Green found that 12% of single cases occurred during sleep, 32% when unconscious, and 25% were associated with some kind of psychological stress, such as fear, worry, or overwork. Some cases show that it is possible to have an OBE while the body continues with complex and co-ordinated activity. However, OBEs are far more common when the physical body is relaxed and inactive.
Most of Green's cases occurred to people whose physical body was lying down at the time (75%). A further 18% were sitting and the rest were walking, standing or were 'indeterminate.' In fact it seemed that muscular relaxation was an essential part of many people's experience. Just a few found that their body was paralyzed. A feeling of paralysis was found to be only rarely a prelude to an OBE.
A difference is found between the 'single' cases and the multiple cases. The latter tended to have had experiences in childhood, and learned to repeat them. The single cases tended to occur mostly between the ages of 15 and 35. Poynton found that many more of his cases came from females, but among the SPR cases there are more males than females. This sort of difference is most likely to be due to sample differences.
Floating and soaring sensations are certainly common. Poynton also found that most of his OBEers saw or felt their physical body. On the contrary, catalepsy rarely occurred. Some subjects mentioned noises or a momentary blacking out, but this did not seem to be the rule. The majority just 'found themselves' in the ecsomatic state. As for the return, for most it was as sudden as the departure. An interesting finding by Green was that more of the subjects who had had many OBEs went through complex processes on separation and return.
Green separated her cases into those she called 'parasomatic,' involving another body, and those she termed 'asomatic' in which there was no other body. Her surprising finding was that 80% of cases were asomatic -- they had no other body. She asked her subjects whether they had felt any connection between themselves and their physical bodies. Under a third said they had, and only 3.5% reported a visible or substantial connection such as a cord. Poynton's results tell a similar story. There seems to be little evidence from the case collections to support the usual details of astral projection.
Green found that on the whole perceptual realism was preserved. Subjects saw their own bodies and the rooms they traveled in as realistic and solid. Even when the scene appears to be perfectly normal there may be slight differences. Some her subjects said that everything looked and felt exaggerated. The experience is typically in only one or two modalities: vision and hearing. Green found that 93% of single cases included vision, a third also had hearing, but the other senses were rarely noted. Another interesting feature of the OBE world is its lighting. In some mysterious way the surroundings become lit up with no obvious source of light visible, or else objects seem to glow with a light of their own.
Perhaps the most important question about the OBE is whether people can see things they did not know about -- in other words whether they can use ESP in the course of an OBE. Among Green's subjects, some felt as though they could have seen anything, but lacked the motivation to test out such an ability. Another related question is whether subjects in an OBE can affect objects, or have the power of psychokinesis. On the whole the evidence is against that possibility.
The last feature which Celia Green found to be common in OBEs is that a spontaneous OBE can have a profound effect on the person who experiences it. Sometimes OBEs can be very frightening, sometimes exciting and sometimes they provide a sense of adventure. Interestingly, Green found that fear was more common in later, not initial experiences. Pleasant emotions are also common.
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