Mentalism is a performing art in which its practitioners, known as mentalists, appear to demonstrate highly developed mental or intuitive abilities. Performances may appear to include hypnosis, telepathy, clairvoyance, divination, precognition, psychokinesis, mediumship, mind control, memory feats, deduction, and rapid mathematics. Mentalists perform a theatrical act that includes special effects that may appear to employ psychic or supernatural forces but that are actually achieved by "ordinary conjuring means", natural human abilities , and an in-depth understanding of key principles from human psychology or other behavioral sciences.