Often the person does not even realize that he has answered these promptings. After a suitable delay the cold reader will then repeat what has just been learned to the amazement of his audience. Verbal feedback to try-ons and other ploys helps explain the phenomenal success of psychic hotlines, which is now almost a billion dollar a year industry. Visual feedback is not vital to experienced cold readers, verbal feedback alone often provides enough information so that the subjects are virtually open books. Deprived of feedback, the process of cold reading grinds to a halt.
Muscle reading is yet another tool for surreptitiously acquiring information.
It involves direct contact with the person being read, either holding a hand or an arm or touching something the client is holding like a handkerchief. Contact like this permits the reading of involuntary muscle movements that can be used to gauge a clients reaction. These reactions inform the cold reader if he is hot or cold allowing him to go from general to more specific statements. Cold readers also know that certain aspects of human psychology itself helps in their endeavors. One phenomenon, called subjective validation or selective memory, is especially important.