An obsession are pattern of thoughts that are intrusive, which means that the individual has no control over them. They are usually images that are uncomfortable for the individual and or usually grotesque in nature and they produce distress to the individual.
A compulsion is a behavior that is repetitive that when performed it lowers the anxiety that the individual is experiencing associated with his/her obsession.
Example: Paul has an obsession with being violent and hurting his little brother. He knows he loves his brother but he has this recurrent images of him punching his brother and it causes him significant distress.
When he has the images, the only thing that eases his anxiety is counting his steps and he does it repeatedly during the day.
They avoid being detected because this would throw off the behavior patterns that exist naturally and they don't want their presence being known since this might throw it off.<span />
