Mommy, mommy, mommy," your young son asks frantically. "can we buy a new playstation ®3 console with all of the games and the wireless controllers so that we don't have to sit near the television? " "no," you reply, "we can't afford to buy all of that! " seemingly unperturbed by your rejection, your son comes back with "then can we just buy one new game for our playstation ®2? " "okay, i guess so," you answer, not realizing that your precocious son has taken a social psychology class and has just used the technique to get what he wanted.