What does "it" refer to ?

Hi~ In the last sentence below, what do you think the pronoun "it" refers to in this context ?

The brain?

Or does "it" equal to the phrase "to violate~ and produce~"?

Thanks for your help~

The first aspect of cyberbullying that impacts human behavior is the element of anonymity. Researchers placed healthy normal adults in a dark padded room (utter invisibility) and through a specialized camera recorded
behavior. Individuals confident that no one would know who they were displayed a sense of freedom that allowed them to cross the boundaries of social norms and decency. When the brain perceives that behaviors are void of all accountability, it is prone to violate social norms and produce increased levels of affection and aggression.