David Spiegel, associate chair of psychiatry and behavioral sciences is an expert on the science of hypnosis. Instead of thinking in terms of a trance, a spooky loss of control to a professional manipulator, he says the phenomenon is better described as a “flow state”. We all know this feeling, sometimes described as “being in the zone”, where time seems to stop and you feel thoroughly immersed in an activity. Hypnosis, like meditation, is just a special version of that normal, desirable human psychological state.
Spiegel makes an app, Reveri, which attempts to package Spiegel’s hypnosis sessions into a series of recorded steps. For $15/month, the app claims to help you achieve your goals of healthier eating, reduced anxiety, better sleep, and more.
Andrew Huberman did a podcast episode with David Spiegel where this is discussed in detail. About 2/3rds of people are hypnotizable, including Huberman. You can test this with a “eye roll”, to see if when moving your eyes up, the whites are visible. See Podcast Notes and also notes from Juan Pablo Aranovich
Time magazine (offline) has a short overview of the subject, including additional details from Spiegel.