A major insight into human behavior from pre-internet era studies of communication is the tendency of people not to speak up about policy issues in public—or among their family, friends, and work colleagues—when they believe their own point of view is not widely shared. This tendency is called the “spiral of silence.”
Some social media creators and supporters have hoped that social media platforms like Facebook and Twitter might produce different enough discussion venues that those with minority views might feel freer to express their opinions, thus broadening public discourse and adding new perspectives to everyday discussion of political issues.
Before the internet the advice was “Don’t talk about sex, politics or religion at the dinner table”. Still true, apparently.