The highest tier of psychologist is the dreamwalker. He learns it not in sleep, but in waking: the ability to capture, widen, and sustain those fragments of dreaming which occur at almost all moments of sentience. The art of microhypnosis: he does not so much "enter" a dream, but dilates a fragmented dream opportunistically with unconscious intent. This is why the most effective, and also most dangerous psychologists are instinctual: one has to know what one wants. It's not possible to generate deep communicative resonance with merely conscious activity: most meaningful transmission occurs in omission, association, subtext.
But what seems like the ability to hypnotize, is largely the ability to cancel distraction: actually every sentient creature moves between many simultaneous and orthogonal trances at once, the interoperations of which produce contextually rich behaviors... Every trance is the result of the isolation of a fewer set of perceptual-behavioral loops than normally operative. What then causes that stasis which gives it away? Just this: the temporary dominance of one instinctual systemic response over many others - instinct spends most of its time waiting, and defaults to off. Think of the stalking cat: its eyes fixed, its musculature poised, all other responses suppressed.
To "mesmerize" is to produce a potently multivalent signal while deferring interpretation: to keep everyone awake, interested, but suspended between stimulus and interpretive response. Nothing breaks beautiful trance like premature interpretation: thus the droning, repetitive, uninformative talk of most modern folk, which manages to combine suspiciously optimistic monotony with a marching thrum of numbing certainty at every step. This is antitrance: a shallow fitful sleep which rests nowhere, which constantly strums the same note in response to every input in order to preclude associative traversal... To suppress premature interpretation: that happens to be one of the ingredients which Freud discovered was essential to the exploration of unconscious valence - everyone likes to forget that Freud began as a neurologist exploring the power of hypnosis.
If you get the feeling sometimes, that my writing induces mild trance, you are beginning to understand me. But no one can induce receptivity where there is none, and every dream is a "shared dream" - because we are never alone within this sloshing nucleic acid tidepool called terrestrial life: to be conscious is not to be alone, only to produce the illusion of useful unity where there is plurality. It's no accident that every nomadic people on the planet considered the dreamstate to be that place where contact with ancestors was most likely... So what are we doing together then? I am speaking to you across the narrow genetic footbridge which separates us, a mere 200,000 years of branching at most: as a single species, we are of the same body. Our nervous systems resonate so readily, because they are hardly different - only I know how to make mine sing with words, such that it becomes a swaying rhythm built on the rhythms of heart, blood, stomach. But it's your power I'm using: all I can do is defer the distraction of your garrulous narrative consciousness with a flood of irresistible poetry, such that latent wakefulness finds itself in the midst of a suddenly stilled landscape - depth of dreaming comes when the wakeful coexists with unconscious topology without disturbing its dendritic overdetermined process... In other words: the ability to witness, respond, and even manipulate, without imposing the brutality of singular valence so typical of the forebrain. The dilation of fragmented dreams: there is no more significant channel of communication I know of, and I've looked.