Using Rooting Interest Techniques and Their Opposites to "Dial Up" or "Dial Down" an NPC's Likability and the Degree to Which We Identify with Him or Her
Any Rooting Interest Technique, flipped upside down, can make a character unlikable and make us unwilling to identify with that character. For instance, it's a Rooting Interest Technique to have a character risk sacrificing himself for another person who's in danger. Flip this upside down, and it makes the person unlikable.
Thus, we have a sort of dial by which we can control exactly how much we like (or identify with) any particular character.
There are many uses for this "Rooting Interest Dial," such as: