Heterogeneity in high hypnotic suggestibility: Models, evidence, and synthesis.

Most empirical studies and theoretical models in research on suggestion and hypnosis presuppose that highly suggestible individuals comprise a uniform population. This assumption contrasts with consistent evidence for heterogeneity in this group, yet these findings have not been systematically integrated or evaluated against competing models of heterogeneity. In this article, I first outline the characteristics of heterogeneity among highly suggestible individuals, highlight methodological considerations, and review the assumptions of different models of heterogeneity. Next, I consider evidence for heterogeneity spanning responsiveness to hypnotic inductions and suggestions, strategy use during response to suggestion, developmental trajectories, cognitive-perceptual profiles, and symptomatology. I identify key limitations in this research area, highlight convergent findings within and across these domains, assess the explanatory scope of different models, and propose priorities for future research on heterogeneity. Elucidating the characteristics and latent structure of heterogeneity among highly suggestible individuals is essential for advancing our understanding of the neurocognitive substrates of suggestion.