Australian Sheep-Goat Scale

Lore & Background

The scale's item selection criterion is whether the topic contravenes philosopher C. D. Broad's 'Basic Limiting Principles', which set limits on mind in a mathematically describable universe. The scale excludes items on astrology, cryptozoological creatures, and extraterrestrial intelligence. The term 'Australian' distinguishes it from other nations' instruments, such as the Icelandic Sheep-Goat Scale. A believer is termed a 'sheep' and a disbeliever a 'goat', after the New Testament simile in Matthew 25:31.

Reader's Guide

The Australian Sheep-Goat Scale is significant as a standardized tool for quantifying paranormal belief in psychological and parapsychological research. Its forced-choice version is the most popular, though visual analogue and Rasch scaled versions exist and yield approximately the same answers. A background paper on scale construction and empirical findings has been published. Studies using the scale have discovered a relationship between narcissistic personality and paranormal belief, and a 2011 study found a significant interaction effect between Sheep-Goat score and type of coincidence, suggesting that people with lower thresholds of surprise when experiencing coincidences harbor higher paranormal belief. The scale's grounding in Broad's limiting principles provides a theoretical framework distinguishing it from broader supernatural belief measures.

Did You Know?

• The scale's items include statements about ESP, precognitive dreams, life after death, and psychokinesis.
• The terms 'sheep' and 'goat' derive from the New Testament simile in Matthew 25:31.
• The scale was devised in Adelaide, South Australia, to distinguish it from other nations' instruments.
• A 2011 study using the scale found a significant interaction between Sheep-Goat score and type of coincidence.

Origins, Naming, and Philosophical Roots

The Australian Sheep-Goat Scale traces its origins to Michael Thalbourne, who devised the instrument in Adelaide, South Australia. The geographic label serves a practical purpose: it distinguishes this particular questionnaire from parallel instruments developed elsewhere, such as the Icelandic Sheep-Goat Scale. The playful nomenclature of "sheep" and "goat" draws on a New Testament passage—Matthew 25:31—where Christ is depicted separating people the way a shepherd divides sheep from goats. In the ASGS context, a "sheep" is someone who affirms at least some paranormal claim, while a "goat" is a skeptic who rejects such claims. Thalbourne's overarching goal was to create a reliable, standardized questionnaire that could gauge just how deeply a respondent embraces paranormal ideas. The scale was not built on arbitrary topic selection; instead, each item had to pass a specific philosophical filter rooted in the work of philosopher C. D. Broad, whose Basic Limiting Principles define the boundaries of what mind can do within a mathematically describable universe. This criterion deliberately excludes topics like astrology, cryptozoological creatures, and extraterrestrial intelligence, keeping the instrument focused on a narrower class of anomalous claims.

Structure, Items, and Scoring Mechanics

The most widely adopted iteration of the ASGS, published by Thalbourne in 1995, consists of eighteen discrete statements that respondents evaluate. Sample items probe beliefs in extrasensory perception, the phenomenon of precognitive dreams that the respondent considers more than mere coincidence, the existence of an afterlife, and psychokinesis, which the scale defines as mind acting directly on a physical system with no known mediating energy. For each statement the respondent chooses among three options: "true," "uncertain," or "false." These map onto a simple point system of two, one, and zero respectively. Summing the points across all eighteen items yields a composite score that can range from a minimum of zero to a maximum of thirty-six. Because respondents must select from a fixed set of options rather than placing their answer on a continuous line, this particular format is commonly referred to as the Forced Choice version. Thalbourne later published a dedicated background paper detailing both the construction process and the empirical findings accumulated with the scale, providing researchers with a transparent account of its development and psychometric behavior.

Alternative Formats and Cross-Version Consistency

Although the Forced Choice format dominates the research literature, Thalbourne and subsequent researchers developed alternative scoring approaches to suit different methodological needs. The two most frequently encountered alternatives are the visual analogue scale version, in which respondents mark a position along a continuous line rather than picking a discrete category, and the Rasch scaled version, which applies item-response theory to calibrate item difficulty and respondent ability on a common metric. Importantly, empirical comparisons have indicated that these three formats—Forced Choice, visual analogue, and Rasch scaled—produce approximately equivalent answers when used to address the same research questions. This cross-version consistency is a significant methodological strength: it suggests that the underlying construct being measured, namely degree of paranormal belief, is robust enough to survive changes in response format. For researchers designing studies, this means the choice of version can be guided by practical considerations such as data-analysis preferences or the cognitive demands placed on participants, without fearing that the format itself will distort the substantive findings.

Empirical Applications and Notable Findings

The ASGS has served as a measurement tool in a variety of personality and cognitive studies beyond simple paranormal-belief surveys. One line of research uncovered a meaningful relationship between narcissistic personality traits and scores on the scale, suggesting that individuals with stronger narcissistic tendencies may be more inclined to endorse paranormal claims. A particularly informative 2011 investigation examined how the experience of coincidence interacts with paranormal belief, using the ASGS as the dependent measure. The study revealed a significant interaction effect between the Sheep-Goat score and the type of coincidence encountered. Specifically, participants who reported a lower personal threshold for feeling surprised by coincidental events tended to harbor stronger paranormal beliefs than those with a higher threshold of surprise. This finding implies that the relationship between everyday coincidences and paranormal conviction is not uniform; rather, it is modulated by an individual's subjective sensitivity to unexpected events. Together, these studies illustrate the ASGS's utility as a bridge between personality psychology, cognitive perception, and the study of anomalous belief.