During his decades of publication, Banner has been portrayed differently, but common themes persist. Banner, a physicist, is sarcastic and seemingly very self-assured when he first appears in "Incredible Hulk" #1, but is also emotionally withdrawn. Banner designed the gamma bomb which caused his affliction, and the ironic twist of his self-inflicted fate has been one of the most persistent common themes. Arie Kaplan describes the character thus: "Robert Bruce Banner lives in a constant state of panic, always wary that the monster inside him will erupt, and therefore he can't form meaningful bonds with anyone." As a child, Banner's father Brian often got mad and physically abused both Banner and his mother, creating the psychological complex of fear, anger, and the fear of anger and the destruction it can cause that underlies the character. Banner has been shown to be emotionally repressed, but capable of deep love for Betty Ross, and for solving problems posed to him. Under the writing of Paul Jenkins, Banner was shown to be a capable fugitive, applying deductive reasoning and observation to figure out the events transpiring around him. On the occasions that Banner has controlled the Hulk's body, he has applied principles of physics to problems and challenges and used deductive reasoning. It was shown after his ability to turn into the Hulk was taken away by the Red Hulk that Banner has been extremely versatile as well as cunning when dealing with the many situations that followed. When he was briefly separated from the Hulk by Doom, Banner became criminally insane, driven by his desire to regain the power of the Hulk, but once the two recombined he came to accept that he was a better person with the Hulk to provide something for him to focus on controlling rather than allowing his intellect to run without restraint against the world.