How is male aggression explored throughout the play?
In addition to Romeo and Juliet being a play about young romance, it is also a play that deals with angry young men and the destructive qualities of masculine aggression.
This fact is most evident in the duels in act 1, scene 1 and act 3, scene 1. In both scenes, we see masculine gender roles that are reliant on the aggressive rapier duel. Sampson, for instance, challenges Abraham and Balthasar with "draw if you be men" (1.1.57), thus linking masculinity to male aggression via sword combat.
Later, reflecting on Mercutio's death and his reluctance to fight Tybalt, Romeo laments "O sweet Juliet, / Thy beauty hath made me effeminate / And in my temper soft'ned valour's steel" (3.1.113-15), which again links masculinity (the antithesis to Romeo's notion of effeminacy) to fighting in a rapier duel. Significantly, it is this duel, which results in Tybalt's death and Romeo's banishment, that we most fully see the devastating effects of masculine aggression: by linking masculinity to aggression and the violence of rapier duels, the angry young men of the play bring about its tragic end through the ripple effect of their actions.
Thus, in the end male aggression become a chaotic destabilizing force that threatens—through the deaths of many of Verona's most prominent young citizens—the very stability of civic order.