In a popular movie about the Mafia, the head of the family chastises one of his sons, Sonny, for letting other people know what he was thinking and feeling. "Never let anyone outside the family know what you are thinking," the Mafia boos says to Sonny. From an emotions perspective, the father is speaking about

Display rules

Explanation:

Display rules are a social group or culture's informal norms about how to properly express emotions. The norms of a group helps identify where and when it is right to express emotions and the levels at which these emotions are exhibited.  Atimes, social norms directs when emotional displays should be subdued.  Display rules are often used as a way to protect the feelings of oneself or other people.  A typical example of display rules is described in the passage as the head of the family scold his son to always try to control his emotions in public.