The rainbow ruse
The rainbow ruse is a crafted statement which simultaneously awards the subject with a specific personality trait, as well as the opposite of that trait. With such a phrase, a cold reader can "cover all possibilities" and appear to have made an accurate deduction in the mind of the subject, despite the fact that a rainbow ruse statement is vague and contradictory. This technique is used since personality traits are not quantifiable, and also because nearly everybody has experienced both sides of a particular emotion at some time in their lives.
Statements of this type might include:
* "Most of the time you are positive and cheerful, but there has been a time in the past when you were very upset."
* "You are a very kind and considerate person, but when somebody does something to break your trust, you feel deep-seated anger."
* "I would say that you are mostly shy and quiet, but when the mood strikes you, you can easily become the center of attention."
A cold reader can choose from a variety of personality traits, think of its opposite, and then bind the two together in a phrase, vaguely linked by factors such as mood, time, or potential.