Disguise or Costume?

The article "Playing Indian" mentions several instances of Americans who disguised themselves without really hiding their identities.  Colonists dressed as Indians, and nobles dressed as commoners.  Deloria points out that these outfits didn't serve to make the perpetrators anonymous or shift the focus of blame.  Rather it seems the disguises functioned much the way costumes function in a performance.  The dissenting colonists were trying to put themselves into a character, a character to suit their actions.  Dressing up like a Indian might help a Bostonian perpetrate crimes that he would have never seen himself doing as an upstanding member of society.  The outfit still creates a new identity, but it is an identity that projects itself internally as well as externally.  The actor uses his costume to add credibility to his character which helps him perform his role with more confidence.  But there is another important analogy to a stage costume.  A costume is a lie, a fabrication.  Of course, the colonist dressed up like an Indian is still a white, Christian who has been raised in civilized society.  The disguise is just a tool to empower himself.