 The theory explains that when people have that mutual social influence it motivates them to want to “co-ordinate their behavior in ways that are relevant to that identity.” (Haslam, 2012) This is important because this is how people develop their views on the world and their thoughts, feelings, and actions.To completely understand the importance of theory, you must know the whole story and the person's intentions.It is like the Phineas Gage situation; Macmillan wrote an article on how over the centuries the story of Phineas Gage and what happened to him has changed or does not include all the details.