The initial hypothesis for explaining declines in psi effects was declining motivation, enthusiasm, and novelty by the experimenters and/or participants (Pratt, 1978; J. B. Rhine & Pratt, 1957). This hypothesis may contribute to a loss of effect, but it does not explain the full range of actively evasive effects. The overall evidence suggests that the intended, motivated effects are avoided during the actively evasive phase. Something more than reduced motivation by the experimenters and participants seems to be involved.

Historically, inconsistent psi effects were attributed to unconscious processes (J. B. Rhine, 1946c). However, labeling the unknown factors as unconscious has provided little explanatory or predictive value after 50 years of discussion and research. More specific hypotheses are needed.

The most frequently discussed motivation that could inhibit psi is fear of psi (Batcheldor, 1984; Braud, 1985; Eisenbud, 1963/1992b; Tart, 1984). The arguments supporting and opposing this hypothesis have been discussed previously (Kennedy, 2001). There is little evidence suggesting that people fear the weak statistical effects in experimental research, yet these effects become actively evasive. Further, the fact that some people devote great effort to attempting to elicit psi does not seem consistent with fear of psi. If fear or resistance to psi causes the inhibition of psi effects, the source would seem to be external to those directly attempting to elicit psi.

An alternative approach recognizes that psi experiments may be carried out against a background of powerful supporting and opposing motivation and psi influence. This possibility follows directly from the traditional assumption in parapsychology that psi is basically independent of space and time and is related to human motivation. Taken at face value, experimental outcomes could be influenced by many people who hear about or care about the results.

This possibility appears consistent with the chronic state of psychical research: There is sufficient evidence for psi to maintain the interest and enthusiasm of those strongly interested in psi, but not the consistent evidence that would threaten the ardent skeptics. A dynamic and nearly balanced equilibrium between opposing forces appears to characterize the situation. As noted earlier, many people have strong motivations on both sides of the psi issue.

The key question is to what extent does skepticism cause unsustainable psi versus unsustainable psi cause skepticism? If the primary direction of causation is that unsustainable psi causes skepticism, then it may be more productive to look for another explanation for unsustainable psi.

However, there is a rationale that the strongest opposition to psi may derive from genetically based personality characteristics. The extreme skeptics are predominantly males who place great value on rational thinking and who focus their efforts on trying to influence others  (Blackmore, 1994; Hansen, 1992). Studies of belief in ESP indicate that disbelief is associated with male gender and a greater internal locus of control (belief that they control the events in their lives; Irwin, 1993). However, discussion of these findings has usually focused on belief in psi being associated with females and external locus of control.

From an evolutionary perspective, a rational, practical style of thinking, combined with a drive to influence and control the world around them, would provide an impetus to develop tools and technology and an ability to successfully compete for resources and produce descendants. Geary (1998) brought together a wide diversity of converging evidence across species, human cultures, and human stages of life that shows that “men are biologically destined to compete with each other for social status and for the attainment of cultural success” (p. 324). He also summarized extensive evidence that from infancy onward, males tend to have more interest in inanimate objects and females more interest in people (pp. 217–239). The traits commonly associated with males across 25 countries include aggressive, rational, enterprising, inventive, and resourceful (Williams & Best, 1986).

People who do not share the drive for rational thinking and control may be a threat and natural target for the more extreme members of this group. The possibility that different values and less rational, less controlling styles of thinking could lead to prominence and status may be fundamentally threatening. This may explain the irrational degree of ridicule in the writings of the extreme skeptics and their equally irrational fear that belief in psi is a dangerous threat (Hansen, 1992).

Feelings of threat and hostility were defining characteristics for the Committee for the Scientific Investigation of Claims of the Paranormal (CSICOP). Martin Gardner, a member of the all-male founding board, described the early split that resulted in Marcello Truzzi leaving the group:

[Truzzi] wanted our periodical to provide scholarly discussion between skeptics and fringe scientists. He disliked calling anyone a crank. Marcello has always had a friendly, at times admiring, attitude toward pseudoscientists and psychic con artists. He seldom perceives them as any sort of threat to science or to the public. . . . For the rest of us on the founding board, to expect our periodical to treat outrageous pseudoscience with respect was like expecting a liberal or socialist magazine to seek articles by right-wing extremists. (Gardner, 2001, p. 360)

As Gardner indicates, CSICOP is more like a political propaganda organization than a scientific organization.

The other pole with regard to attitude toward psi may be those who have a strong innate sense that life is interconnected and has a higher purpose. Those with these characteristics often view psi as evidence for and a natural manifestation of this interconnectedness and higher purpose. These characteristics are associated with spirituality and may have natural selection advantages because they promote cooperation, and optimism and resilience when confronting situations that cannot be controlled. Epidemiological studies indicate that religion or spirituality is associated with better physical and mental health (Koenig, McCullough, & Larson, 2001; Mueller, Plevak, & Rummans, 2001). Women tend to be more religious or spiritual than men (Stark, 2002) and to develop altruistic, reciprocal relationships, whereas men tend to base relationships on power and dominance (Campbell, 2002; Geary, 1998). The extreme skeptics tend to consider that both religion and belief in paranormal phenomena are irrational (Hansen, 1992).

The hypothesis of a genetic component for attitude toward psi is also supported by evidence for genetic components for (a) the psi-related personality characteristics absorption (Tellegen et al., 1988) and hypnotic susceptibility (Morgan, 1973), (b) interest in religion and spirituality (Bouchard, McGue, Lykken, & Tellegen, 1999; Kirk, Eaves, & Martin, 1999; Waller, Kojetin, Bouchard, Lykken, & Tellegen, 1990), and (c) possibly psi ability (Cohn, 1999). Stark (2002) concluded that the difference in spirituality between men and women appears to have a genetic component.

Both the rational, controlling and interconnected, spiritual personality characteristics may have adaptive value and contribute to the optimum diversity of the human species, and to a balanced background of motivations supporting and opposing psi. A more detailed examination will likely find that these characteristics consist of multiple factors and some of the factors may be separate dimensions rather than extremes of a continuum. People who are unsure or indifferent to psi and those who want to use psi instrumentally must also be recognized.

Various aspects of this model can be tested. Using the methods of behavioral genetics to investigate the genetic aspects of belief and skepticism is an obvious starting point. The fact that skeptics are a minority of the population may indicate that all people do not contribute equally to the background psi. The background opposition could be due to a subgroup of people with psi ability and high motivation. Also, the evidence that males may typically demonstrate greater PK influence than females (Dunne, 1998) is consistent with the male drive to assert themselves and may have implications for a disproportionate background influence by skeptics.

Strategies that influence psi effects may also be tested. Although this model can be precisely handled as an observational model, the critical assumptions are the independence of time and space rather than the act of observation.

Bierman (2001) suggested that the number of people becoming aware of and potentially influencing psi experiments increases as experiments are repeated. Presumably, the background opposition to psi has an increasing role with replication, while the motivation and novelty for the experimenters may decline. The evidence that psi effects abruptly drop after meta-analyses (Houtkooper, 1994, 2002) is particularly relevant. Bierman (2002) also suggested that the reported stability of the classified Star Gate research may reflect limitations on the number of persons potentially influencing the results. Houtkooper (2002) extended this idea by suggesting that the restricted information of classified research may allow the skeptics to dismiss findings without being confronted with strong evidence. Similarly, the idea that stronger psi occurs with weak methodology also may reflect less attention and negative motivation by skeptics.

If these ideas are correct, the optimum conditions for psi results would be for one person or a few people with psi ability to carry out self-tests with the firm constraint that no one else will ever learn of any positive outcomes. This is consistent with the strategy “go and tell no one” recommended by some proponents of psi (e.g., Sinetar, 2000). Other experiments could be carried out with varying degrees of information distribution, including simulating classified research. One interesting strategy would be to attempt to reverse the declines by having more restricted distribution of information and perhaps lower quality methodology as the research progresses.

Although these ideas are interesting and should be tested, I personally doubt that they will turn out to explain the unsustainable nature of psi. This expectation is based on my experience with psi (Kennedy, 2000) and the likelihood that psi is not as anthropocentric as assumed with these ideas. At the same time, I think the idea that genetic and gender factors are significant in the polarization of psi beliefs is almost certainly true.

Eisenbud (1963/1992b) proposed that the declines and lack of usefully repeatable results in psi research reflect a fundamental, insurmountable property of nature. He suggested that psi has a role in and is constrained by the basic laws of probability. Beloff (1994) proposed ideas with similar conclusions. However, these speculations focus on the actively evasive phase and offer no explanation or insights for the reliable phase of psi or for the transition between reliable and evasive psi.

Lucadou (1988, 2001, 2002) proposed that usefully reliable psi is not possible based on a general systems theory model that includes the meaning of the psi event as a critical factor. This model attempts to combine physical and psychological aspects into one overall system that has boundaries and limitations determined by the meaning or “pragmatic information” of the situation. Experimental outcomes change as this meaning changes.

The model predicts that psi effects can occur in situations that are novel for those involved, but the effects will vanish or change if useful or confirming information is involved. Lucadou (2001) suggested that psi researchers should make sufficient changes when replicating studies to maintain novelty and that the ideal situation would be to keep the experimenters and participants unaware of the previous outcomes for a line of research. The model appears to preclude practical application of psi. At a minimum, this model is a stimulating effort to deal with the perplexing properties of psi.

However, it appears to me that the reliable phase of psi sometimes involves successful confirmation or useful information that conflicts with the basic predictions of this model. Also, human meaning has a pivotal role in this model. Here too, I think it is likely that psi is not as anthropocentric as assumed in this model. However, the key concepts and terms in the model (“pragmatic information,” “organizationally closed system,” etc.) cannot be quantified at present and are sufficiently ambiguous and complex that the model can probably be adapted to a wide range of outcomes.

It may be useful to note that researchers can develop similar hypotheses based on inferences from previous empirical findings without the need for the esoteric jargon and equations from systems theory. In fact, with the current state of knowledge, it is not clear that the jargon and equations contribute value beyond simple predictions based on consistency with the experience from previous research.

The ideas discussed in this section focus on the attitudes and knowledge of those directly involved in a study, whereas the ideas discussed in the previous section focus on the attitudes and knowledge of those outside the experimental setting. In principle, these differences can be tested by controlling the dissemination of information about experimental outcomes. For example, cases when multiple studies are initially reported publicly at one time can be compared with cases when sequential studies are reported individually.

The most obvious, empirically grounded model for the unsustainable nature of psi is that the primary function of psi is to induce and maintain a sense of mystery and wonder. To fulfill this purpose, psi effects must remain mysterious and unsustainable. William James’s (1909/1960) comment that psi appears to be intended to be baffling would be precisely correct. Psi effects may inspire and maintain the interconnected, spiritual dimension of humanity by inducing a sense of mystery and wonder. In addition, some psi effects seem consistent with intervention or guidance by a higher consciousness (Kennedy, 2000).

This hypothesis is similar to, but may qualify, the idea that psi effects are a process of personal transformation. Several writers have suggested that psi can best be understood by examining the personal meaning and transformative effects of psi experiences (Kennedy, 2000, 2001; Taylor, 1995; White, 1990, 1993, 1994). White (1993) suggested that the best research strategy may be to let psi lead us rather than to try to control or apply psi.

However, looking to psi to guide one’s personal growth or research may be another form of application of psi that overlooks the unsustainable nature of psi. The role of psi may begin and end with inducing a sense of wonder. Personal transformation and growth may be inspired by the mystery of psi experiences, but psi may be an unsustainable source of information of any type—whether the information relates to personal growth or to predicting commodities markets.

This hypothesis does not indicate who or what is the source of psi. Presumably, psi effects result from the motivations and meanings of individuals interacting with another agency that allows or causes a psi effect to occur if the effect inspires mystery and wonder. For the present, labeling the unknown agency as a “higher consciousness” without attempting further clarification is probably as useful as offering untestable speculations about its nature or relationship to human consciousness and unconsciousness.

Once the scientifically uncomfortable step of considering that a higher consciousness may cause the unsustainable nature of psi is taken, more diverse properties of psi become plausible. In particular, the higher consciousness could allow psi effects in accordance with more complicated rules involving motivation and meaning, and particularly personal growth and spirituality. From a scientific perspective, the guiding principle must be to focus on the simplest, most testable models that are consistent with available data.

With this approach, the first empirical question is whether psi has any function in addition to inducing a sense of mystery and wonder. This requires more than a superficial listing of some cases in which psi appeared to save someone from harm. If there are many psi cases that induce wonder without a practical benefit and a comparatively small number that have a practical benefit as well as induce wonder, it is likely that the practical benefit is incidental to the main function of the experience. More sustained patterns of consistent experiences converging on a specific outcome would seem to be needed.

Another empirical strategy is to try to identify patterns or rules about when efforts to apply psi are successful and when the evasive phase starts. Most previous explorations along these lines have been limited by focusing on mechanistic principles from quantum physics. The concept of a higher consciousness offers more flexibility for developing testable models.

For example, psi could promote or create diversity for evolution. Psi would not directly guide evolution as various writers have suggested (reviewed in Stokes, 1997), rather psi would influence or enhance the random processes generating the diversity that underlies natural selection. This diversity could apply to human consciousness as well as to traditional biological diversity. Psi would be a creative principle that acts briefly at transition points to generate new states but would not maintain those states or produce sustained effects. The traditional forces of competition and natural selection would determine which states survived. The sense of mystery and wonder resulting from psi could be a side effect or special case of the enhanced diversity

Psi effects are unsustainable. They are sometimes impressive and reliable, but then become actively evasive. One of the most testable models for this property is that psi effects occur against a background of supporting and opposing motivation and psi influence due to the extreme polarization of attitudes toward psi in the population. A more likely explanation is that some type of higher consciousness influences or guides the occurrence of psi. Psi effects induce a sense of mystery and wonder, which may be the primary function of psi. However, other functions are possible and need to be investigated.