In a recent post (called "Is It Rational To Be A Little Crazy?"-see below), I discussed how seeming irrational behavior might make sense if it reveals our emotional state. That means the information we are trying to send out could be more believable since emotions are costly to fake.
But one commentor said that we fake things all the time. Like at work, we act like we like the job (or at least don't hate it). Related to this, there is an interesting looking book (I have not read it) called Private Truths, Public Lies: The Social Consequences of Preference Falsification by Timur Kuran. Here is what one reviewer wrote:
"... people's choices, and even their desires, are not given and fixed, but are a function of social and psychological conditions, above all pressures imposed by other people...Kuran's book is a terrific success."