What is theme of the movie Mean Girls?

Although the
title may refer to the action within the film rather euphemistically as being "mean,"
Mean Girls is ultimately a movie about
bullying. Upon starting her first day of public high school, Cady
Stanton must come face-to-face with The Plastics and their cruel leader, Regina George, the most
popular and nastiest girl in the school. After Regina sabotages Cady's attempt to get together
with Aaron Samuels, Cady decides to get revenge with the help of her outcast pal, Janis, by
targeting Regina's relationship, friend group, and self-image.

Although it
may appear that Cady is seeking justice for the acts of cruelty that Regina has committed
against the school, she is actually just participating in the same sneaky bullying tactics that
Regina has used to exert control over the student population. The rest of the movie examines
this power struggle and the ways that Regina and Cady's brutal behavior escalates. In this
sense, the movie is also one about friendship,
loyalty, and the cost of
betrayal.