I have seen anxiety behaviors maintained by escape. An example of this is being scared of heights and avoiding higher areas on the playground like monkey bars or bridges. I used to work with a client who would get anxious when climbing up a jungle gym and he would look down, so I would tell him not to look down and to climb higher. He would avoid climbing higher and would step off after being a couple feet off the ground. His anxiety was being maintained by escape as he never pushed himself to climb over things.