  In recent years, the ease with which social media can be accessed has led to
the unexpected problem of a shrinkage in information sources. This phenomenon
is caused by a system that facilitates the connection of people with similar
ideas and recommendation systems. Bias in the selection of information sources
promotes polarization that divides people into multiple groups with opposing
views and creates conflicts between opposing groups. This paper elucidates the
mechanism of polarization by proposing a model of opinion formation in social
media that considers users' reactions of empathy and repulsion. Based on the
idea that opinion neutrality is only relative, this model offers a novel
technology for dealing with polarization.
