well i believe whatever your is about anything ,bookish or personalized , there has to some logic behind that, if you'll not based your answer on logical ground, you would vary in your answers and psychologist would spot that, psychologists are there to gauge your personality and its attributes so one need not to make it up, just be your self in a reasonable way,
if your nervous just try to calm your self down,as far as in know they give you a proper time to get your self relax.......