Consumers subconsciously screen out stimuli that they find psychologically threatening, even though exposure has already taken place. this is consistent with the perception factor of selective attention selective exposure perceptual defense perceptual differentiation perceptual organization

Perceptual defense  

Explanation:

The perceptual defense is a process by which a catalyst alarming offensive and disagreeable are either not perceived or per-verted in perception especially when presented as brief flame. It is a non-recognition threatening stimuli. A stimulus may register outside of the awareness and bring about a change in response  

There are two conditions must be there  

1) The stimulus must be relevant  

2) It must be maintained over time.

ever since wwii tmthey always did hated each other.