We mainly just guess

Steven Pinker is a cognitive scientist that has written extensively about the inner workings of the brain.  Part of his findings deal with the ability of the brain to fill in what we selectively want to see, hear, smell and touch.  In his book How the Mind Works, Pinker has a lengthy section about the eye's perception of what it is seeing.  He compares the process to the eye seeing things as a checker board.  The white squares are not seen, but the black ones are.  Even though the picture is not complete, the mind fills in what is not seen venturing a guess at what is being seen.

A conversation with my mom about two years ago proves Pinker's point.  She was driving on a street that she has driven on many, many times.  She pulled to the stop sign, looked both ways, then began to accelerate into the intersection.  A car whizzed by and nearly hit her.  I told her that she was not expecting to see anything because she normally doesn't.  So her vision was controlled by her expectation.  Mother didn't buy the explanation, but the incident exactly  illustrated Pinker's findings.

To illustrate further, I offer the video below.  People think of Disney as a company for children, so they aren't really looking for sexual innuendos in the animated movies Disney produces.  But our expectations control what we see.

The  same is true about how we hear language.   If we think someone is questionable, ignorant, or deceitful, then that's how the words are heard.  If we think that someone is being honest and trustworthy, then that also is how we hear the words.  Fortunately, forensic methods can overcome this "blindness."  The field helps in judging truth value with accuracy.  That's helpful on a number of fronts.  It cuts through the chase in the legal and law enforcement arenas for sure.  It keeps people from babbling dishonest statements at a rate of one every second because they know you understand the language they are using.  It's just nice to have equalizing techniques at your disposal.  It's like going into a battle with an equal number of weapons in your arsenal as what the enemy has.