Overview

Murphy’s investigation of belief effects and personality correlates in ESP performance emerged from a fundamental question: why do some individuals demonstrate measurable psi ability in controlled settings while others do not? Rather than attributing such differences to chance or experimental artifact, Murphy pursued a systematic psychological approach, hypothesizing that stable personality traits and cognitive dispositions shaped psi expression.

This research program was grounded in Murphy’s broader theoretical commitment to understanding psi as a biosocial phenomenon, one embedded in the personality structure and psychological makeup of the individual. He rejected purely mechanistic models of ESP that treated it as a uniform capacity independent of the person’s beliefs, attitudes, and emotional state. Instead, Murphy argued that psi ability was inseparable from personality organization and that meaningful individual differences in ESP performance reflected genuine psychological variation.

The work was conducted primarily during Murphy’s tenure at the City College of New York and through his leadership role at the American Society for Psychical Research (ASPR), where he served as Research Officer and helped establish the institutional framework for rigorous parapsychological investigation. His collaborations with Gertrude Schmeidler and others produced landmark studies that became touchstones for personality-based approaches to psi research.

The sheep-goat effect

Murphy and Schmeidler’s most influential contribution was the systematic investigation of what became known as the “sheep-goat effect”, the finding that participants’ explicit beliefs about the possibility of ESP predicted their performance on ESP tasks. Participants who believed ESP was real and possible (termed “sheep”) consistently achieved higher hit rates on card-guessing and other psi tasks, while those who disbelieved (“goats”) performed at or below chance levels.¹

The initial studies demonstrated that this effect was robust and replicable. When Murphy and Schmeidler administered belief questionnaires before ESP experiments, they found that sheep-goat classification predicted scoring direction with statistical significance. Importantly, the effect was not trivial: sheep often scored substantially above chance, while goats frequently scored below chance, a pattern that suggested belief was not merely influencing conscious guessing strategies but was somehow modulating the underlying psi process itself.²

Murphy recognized that the sheep-goat effect raised profound theoretical questions. The finding implied that psi was not a fixed, mechanical capacity but rather a psychological function sensitive to the participant’s cognitive and emotional stance toward the phenomenon. A person’s conviction that ESP was impossible appeared to inhibit or suppress psi expression, while openness to the possibility facilitated it. This suggested that belief operated not as a mere reporting bias but as a genuine moderator of psi performance.

The sheep-goat distinction also provided a methodological tool for parapsychologists. Rather than treating individual differences as noise to be averaged out, Murphy’s approach elevated personality and belief to the status of independent variables worthy of systematic study. This reframing transformed parapsychology from a search for a universal psi capacity into an investigation of the conditions (psychological, social, and environmental) under which psi abilities emerged.

Personality and biosocial theory

Murphy’s theoretical framework extended beyond simple belief-disbelief dichotomies to encompass a broader personality psychology of psi. He argued that ESP performance was correlated with multiple personality dimensions, including emotional adjustment, social maturity, openness to experience, and psychological flexibility. These traits were not incidental correlates but constitutive elements of the psychological conditions that enabled psi expression.

In collaboration with Schmeidler and McConnell, Murphy developed a comprehensive personality-based model of ESP potential. Their research examined how traits such as neuroticism, extraversion, creativity, and defensive style related to psi scoring.³ The findings suggested that individuals with greater psychological openness, lower defensiveness, and higher emotional stability tended to demonstrate stronger ESP effects. Conversely, rigid, defensive, or anxious personality profiles were associated with suppressed or absent psi performance.

Murphy termed this approach “biosocial” because it recognized that psi abilities were not purely biological capacities but were shaped by social experience, personality development, and psychological adjustment. An individual’s capacity to express psi was thus understood as emerging from the interaction of biological potential with learned patterns of emotional regulation, social adaptation, and cognitive style. This framework anticipated modern biopsychosocial models in psychology and positioned parapsychology within mainstream personality science.

The biosocial perspective also implied that psi abilities could be understood through the same psychological principles that governed other human capacities. Just as social anxiety might inhibit public speaking ability or depression might suppress creative output, psychological defensiveness or disbelief might inhibit psi expression. This made psi amenable to psychological investigation and suggested that understanding personality dynamics was essential to understanding psi phenomena.

Creativity and ESP potential

Murphy’s investigation of the relationship between creativity and ESP potential revealed another significant personality correlate of psi ability. Working with Moriarty, Murphy examined whether individuals scoring high on measures of creative thinking and imaginative capacity also demonstrated enhanced ESP performance.⁴

The results supported a positive association between creativity and ESP potential. Participants who demonstrated greater cognitive flexibility, originality in problem-solving, and imaginative capacity tended to achieve higher ESP scores. This finding suggested that the psychological capacities underlying creative achievement, the ability to think beyond conventional categories, to entertain novel possibilities, and to access non-rational modes of cognition, were also conducive to psi expression.

Murphy interpreted this relationship within his broader biosocial framework. Creative individuals, he argued, possessed personality organizations that were more open to unconventional experiences and less constrained by rigid cognitive structures. They were more likely to tolerate ambiguity, to engage in imaginative play, and to access intuitive or non-analytical modes of knowing. These same psychological characteristics appeared to facilitate ESP performance, suggesting that psi and creativity drew upon overlapping psychological capacities.

The creativity-ESP connection also had implications for understanding individual differences in psi ability. It suggested that psi was not a specialized faculty independent of other cognitive and personality functions but was integrated with broader personality organization. Individuals with creative, flexible, open personality styles were more likely to manifest measurable psi abilities, while those with rigid, conventional, or defensive styles were less likely to do so.

Spontaneous ESP phenomena

Murphy’s commitment to understanding personality correlates of psi extended beyond laboratory experiments to the study of spontaneous ESP experiences. In collaboration with Dale and White, Murphy conducted a systematic survey of spontaneous ESP cases, examining whether the personality patterns observed in laboratory settings were also evident in naturally occurring psi phenomena.⁵

This research represented an important methodological contribution, as it bridged the gap between controlled experimentation and naturalistic observation. Rather than treating spontaneous cases as anecdotal or unreliable, Murphy developed systematic procedures for collecting, categorizing, and analyzing reports of ESP experiences. The resulting case collection provided a rich database for examining how psi manifested in real-world contexts.

The spontaneous cases supported and extended the laboratory findings. Individuals reporting spontaneous ESP experiences often exhibited personality profiles consistent with those of high-scoring laboratory participants: openness to psi phenomena, psychological flexibility, and creative or imaginative dispositions. Conversely, cases were less frequently reported by individuals with rigid, skeptical, or defensive personality styles. This convergence between laboratory and spontaneous data strengthened Murphy’s theoretical framework by demonstrating that personality-psi relationships were not artifacts of experimental procedure but reflected genuine psychological patterns.

The spontaneous case research also illuminated the contexts in which psi was most likely to occur. Murphy observed that ESP experiences frequently emerged during periods of emotional intensity, heightened intuitive awareness, or relaxed, receptive mental states. These contextual observations aligned with the personality findings: individuals with greater psychological openness and emotional flexibility were more likely to encounter conditions conducive to psi expression.

Legacy and ongoing relevance

Murphy’s research on belief effects and personality correlates in ESP performance established a research tradition that continues to influence parapsychology. The sheep-goat effect has been replicated in numerous subsequent studies, and the personality-based approach to understanding psi remains a central framework in contemporary parapsychological research.

The theoretical implications of Murphy’s work extended beyond parapsychology. By demonstrating that psychological factors systematically modulated psi performance, Murphy contributed to a broader understanding of how personality and belief shape human experience and capability. His work anticipated modern research on expectancy effects, placebo phenomena, and the role of belief in shaping cognitive and perceptual processes.

Murphy’s biosocial framework also provided a model for integrating parapsychology with mainstream psychology. Rather than treating psi as an anomalous phenomenon requiring special explanation, Murphy’s approach positioned psi within the normal range of human psychological variation. This perspective made parapsychology more accessible to psychological science and suggested that understanding psi required the same rigorous personality assessment and psychological measurement employed in other areas of psychology.

The emphasis on individual differences in psi ability also had practical implications. If personality and belief systematically predicted ESP performance, then parapsychological research could be more efficient by focusing on participants likely to demonstrate psi abilities. This suggested that screening for personality characteristics and belief systems could improve the signal-to-noise ratio in psi experiments and accelerate the accumulation of reliable findings.

Murphy’s work remains relevant to contemporary debates about replication and effect sizes in parapsychology. By highlighting the importance of personality and belief as moderating variables, Murphy’s research suggests that failures to replicate psi effects may reflect inadequate attention to individual differences rather than the absence of genuine phenomena. Modern parapsychological research increasingly incorporates personality assessment and belief measurement as standard components of experimental design, a practice directly traceable to Murphy’s pioneering investigations.