Temporal stability of the Launay-Slade Hallucination Scale for high- and low-scoring normal subjects

It has been documented that many normal people report hallucinatory experiences. The Launay-Slade Hallucination Scale is widely used to investigate differences between subjects who score high or low in hallucinatory predisposition. In this study we addressed the question of whether scores remain stable over time. We selected 19 high-scoring subjects and 17 low-scoring subjects (upper and lower quartile) from a group of 243 undergraduate students who completed the scale. These two groups retook the scale after a period of 3 to 6 weeks. 81% received the same classification, which supports the view of hallucinatory predisposition as a stable trait; however, for 30% of the subjects the mean rating at the second time differed more than 3 SDs from the mean rating at the first time. In addition, the mean rating of 19% of subjects changed enough so they did not receive the same classification, indicating that state characteristics may also affect these scores.