Humans can allow other entities--personalities or ideas--to control them to varying degrees. If they allow other persons or concepts to take dominant control of their thoughts and actions, they lose the ability to think or act autonomously. As a personality or an ideology takes progressive control of them, they become possessed (an obsessive, a bigot, an ideologue) and finally end in hysteria--the manifestation of self-limiting or self-destructive tendencies.
In psychology, hysteria refers to the loss of sensory or motor function without organic pathology. The person suddenly cannot hear, see, or feel, or his arm or leg may be paralyzed, or he may be unable to speak--even though the bodily organs are completely functional.
Currently, possession and hysteria are present in much of the world's population. We see these phenomena most clearly in the fixed ideas and obsessive belief-systems of masses of people world-wide who are oblivious to the destruction of their lives by politicians and corporations. The phenomena of possession and hysteria are most evident in the American masses who have lost the ability to see what is happening in America and the world.
As humans become progressively possessed by destructive personalities and ideologies, they ultimately end in suicidal behavior: voting for and supporting people who are deliberately destroying them. They become blind to everyday realities--even to the total collapse of the world economy and the destitution of workers.