What you are describing is specifically known as Selective Exposure.
There is a fairly well known description of selective exposure driven into the realm of cognitive dissonance known as Festinger's Theory which was the work of Leon Festinger but I doubt he is the one you are looking for.
There is an unrelated theory on selective exposure known created by Joseph Klapper that specifically dealt with the effects of mass communication. General selective exposure, general selective perception, and general selective retention are the three observations of humanity made in Klapper's theoretical works. According to Klapper, people are not influenced by mass communication. They filter out as noise any mass communication that does not confirm some already held bias and receive mass communication that does.
It is called Klapper's Selective Exposure
I believe that is the droid you are looking for.