There is this little psychological event which occurs in some people (probably most) during some social experiments. By social experiments, i mean to imply any time two or more people get together and do something. The expectancy effect refers to our tendency to unconsciously shape the results of an interaction based on what we believe the desired outcome to be. Thus, in the Wikipedia example, if my doctor tells me with confidence that the prescribed pills will certainly have a positive effect than the theory behind expectancy effect suggests that i should expect to get better and therefore experience the placebo effect. This is important because the placebo effect has been shown in many if not most studies to be responsible for anywhere between 30% and 50% of the improvements in condition and symptoms reported by depressed persons. 30 to 50 percent? That is pretty good money if you can get it.
I have recently noticed another type of expectancy effect which does not seem to have a name in the psychology literature and seems most closely related to the one we are talking about. It is a type of expectancy effect, only in this particular manifestation, one unconsciously resists compliance to what one perceives to be the desired outcome. Thus, if i feel a person may be testing me in some fashion, i may feel inclined to "mess with their heads" as it were for the simple unconscious purpose of demonstrating my autonomy and my freedom. We know this type of behaviour exists by observing the "occupy wall street" sit-ins. People have assembled not to protest exactly but simply to affirm and assert their right to speak. It is a type of show and tell without necessarily being conflictual with the order in place. Very small children seem to engage in this type of behaviour as well but we call that "opposition". What if it were the adult being contrary and opposite to the child. Necessarily if one is opposite than the other is as well no? Anyway, i am deviating from my original idea as usual. Actually, maybe not so much of a deviation after all. Let's look at an adolescent for a minute. An adolescent will invariably identify with some form of role model. Perhaps the same or opposite sex parent, or someone in the community. That identification may take on a positive or negative form. If the case is positive in the extreme then the adolescent says : "i want to be like that person" if the case is negative in the extreme she says: "that person is an example of everything i do not want to be". In either case, there is an identification with the model. If the identification happens to be negative then that adolescent is disposed towards a type of cognitive influence i would call the counter-expectancy effect. This term refers to one's tendency to do the opposite of what one feels the other expects of them.
If you have come across anything in the psychology literature which expresses this effect more succinctly please forward it to me, otherwise i am going to telephone the American Psychological Association and advise them of my new discovery immediately! (joke).