Gerber theory

Cultivation Theory

Cultivation theory suggests that repeated exposure to television over time can subtly ‘cultivates’ viewers’ perceptions of reality. George Gerber and Larry Gross theorized that TV is a medium of the socialization of most people into standardized roles and behaviors.

This basically means in the terms of newspapers if a paper focuses on one thing for a period of time the audience of said newspaper would have there opinions changed by the story's that they see. For example if a newspaper only portraits Muslims as terrorists then the opinion of Muslims will be bad because of the papers. 

This news papers portraits Muslims in Britain to be sympathizing to the terrorist group "isis". Doing this makes all Muslims look bad, this sells more papers but gives people false information.