Mass hysteria. The girl's behavior in the courtroom when they are accusing the townspeople of witchcraft represents the psychological phenomena of mass hysteria. For example, mass hysteria can be seen when Abigail and the other girls begin repeating what Mary Warren says and pretending to feel a cold wind in the air.
Applicable quote: "Mary Warren: I-I cannot tell how, but I did. I-I heard the other girls screaming, and you, Your Honor, you seemed to believe them, and I- It were only sport in the beginning, sir, but then the whole world cried spirits, spirits, and I- I promise you, Mr. Danforth, I only thought I saw them but I did not." - Act 3
Fear. One example of the power of fear in The Crucible is where Abigail becomes almost like a saint in the community. She uses fear of accusation of witchcraft to build her reputation.
Applicable Quote: "Elizabeth: The Deputy Governor promise hangin' if they'll not confess, John. The Town's gone wild, I think. She speak of Abigail , and I thought she were a saint, to hear her. Abigail brings the other girls into the court, and where she walks the crowd will part like the sea for Israel." - Act 2
Guilt. The most recognizable guilt in The Crucible is from John Proctor concerning his affair with Abigail. When discussing the affair with his wife, Proctor reveals his guilt and that he is pricked constantly by his conscience.
Applicable Quote: "Elizabeth: "The magistrate sits in your heart that judges you." - Act 2