There are several differences in personality between Oedipus and Jocasta, but two most important are her reasoned thinking, even in the middle of extreme stress, and her passive nature. When she sees Oedipus and Creon quarrelling, she tries to make peace. She points out the fallacy in judging before proof is brought, while Oedipus has jumped to the first conclusion, that there is a conspiracy against him, and has taken hold like Jila Monster.
However, when the truth is about to be proven, Jocasta begs him to stop looking. She does not want to know. Oedipus doggedly pursues the real history and Jocasta runs inside to avoid that truth. Jocasta is actually so passive, that when she was faced with the choice between her newborn son or her husband, she deferred to her husband’s judgment and willingly gave up her son to be killed.
She commits suicide to escape the consequences of the truth behind the whole matter, and avoid facing anyone about it. Oedipus is very active, aggressive and controlling, while Jocasta is a reasoned peacemaker who wants to follow a plan to prove something, yet she flees at the first moment when she knows she will face humiliation.