To call someone a liar is a serious charge made when we are very angry. It is surely going to cause a fight. Yet, common sense tells us that some distrust is appropriate.
People do deceive others, even best friends and loved ones.
So, in some ways society encourages distrust. We teach children not to accept rides from strangers. We don't believe ads and salespersons. Politicians say what we want to hear. We believe people are pushed by unconscious forces and don't really know themselves.