Studying new media and their effects also happened long time ago.
Mass media:

• Book, Journal(Magazine), Newspaper, Telegraph, Telephone, Radio, Television, the Internet, etc. . . .
  
• When was Telegraph invented?
  
• What about Telephone?
  
• Radio, Television?
  
  

--> Include(HistoryOfMassMedia) or See History of Mass Media

As you may see in the history of mass media section. There was a consensual atmosphere about the powerful effects of mass media. This was backed up with the studies from the psychology, a newly emerging academic discipline. By the time, that people blindly witnessed the effect of mass media, psychological studies was also rapidly developing. Specifically, around the time, behaviorism was a big issue. For example,

1863 - Ivan Sechenov's Reflexes of the Brain was published. Sechenov introduced the concept of inhibitory responses in the central nervous system. 1900 - Ivan Pavlov began studying the salivary response and other reflexes. 1913 - John Watson's Psychology as a Behaviorist Views It was published. The article outlined the many of the main points of behaviorism. 1920 - Watson and assistant Rosalie Rayner conducted the famous Little Albert experiment. 1943 - Clark Hull's Principles of Behavior was published. 1948 - B.F. Skinner published Walden II in which he described a utopian society founded upon behaviorist principles. 1959 - Noam Chomsky published his criticism of Skinner's behaviorism, "Review of Verbal Behavior." 1971 - B.F. Skinner published his book Beyond Freedom and Dignity, where he argues that free will is an illusion.