Brennan's personality undergoes significant changes throughout the course of the series. Her thinking becomes less rigid in later seasons, something which is observed by Dr. Gordon Wyatt, who notes that she is now able to distinguish the difference between accuracy and truth. In season 4, Booth takes her along to his interrogations and helps her learn how to set aside her scientific perspective and relate with the victim's family and suspects on a more interpersonal level. She is also able to put aside her rationality to support her friends in sometimes irrational pursuits, such as Angela's quest to raise money to save a pig from slaughter, and to comfort Booth, even using science or quoting directly from the Bible to rationalize his religious beliefs. Her sensitivity and empathy towards others are also much improved, seen quite strongly when she comforts his grandfather, and when she attends a funeral so that the victim's single mother won't be alone. She also displays more "typical" human emotions when in extreme stress. One example of this is her fear of snakes in "The Mummy in the Maze," when a girl is in the process of being scared to death in a room, the floor teeming with snakes. This goes against her empirical nature, as, when Booth tells her that the snakes aren't venomous, she states that she is aware, but still refuses to step in the room, causing Booth to carry her on his back. Usually strong-willed and independent, she has since admitted on multiple occasions that her happiness was contingent on Booth's and could not envision herself living a fulfilled life without him.