Answer:
Group polarization
Explanation:
In the field of psychology, group polarization is a term that refers to the tendency of a group to influence its members in a way that their most extreme beliefs are reinforced, even if they held no particularly extreme views before joining the group, which in turn leads to the group moving more and more towards an even more extreme position. A side effect of group polarization is that when engaged in discussion with people who hold different views, often times the end result is not a more nuanced and balanced approach, but a reinforcement of people's original views.
In our case, Stephanie and Luke were friends despite their different political views. But discussing their views online meant both mingling with people who held their same opinions and arguing with people who had opposite views, leading to a case of group polarization - their initial views grew further and further apart as a consequence of their most extreme views being reinforced. Eventually, the gulf between their ideas became so large that they drifted apart. Several studies have confirmed this phenomenon of group polarization, which has become extremely common thanks to the widespread of the internet.
