  Politically divided societies are also often divided emotionally: people like
and trust those with similar political views (in-group favoritism) while
disliking and distrusting those with different views (out-group animosity).
This phenomenon, called affective polarization, influences individual
decisions, including seemingly apolitical choices such as whether to wear a
mask or what car to buy. We present a dynamical model of decision-making in an
affectively polarized society, identifying three potential global outcomes
separated by a sharp boundary in the parameter space: consensus, partisan
polarization, and non-partisan polarization. Analysis reveals that larger
out-group animosity compared to in-group favoritism, i.e. more hate than love,
is sufficient for polarization, while larger in-group favoritism compared to
out-group animosity, i.e., more love than hate, is necessary for consensus. We
also show that, counter-intuitively, increasing cross-party connections
facilitates polarization, and that by emphasizing partisan differences, mass
media creates self-fulfilling prophecies that lead to polarization. Affective
polarization also creates tipping points in the opinion landscape where one
group suddenly reverses their trends. Our findings aid in understanding and
addressing the cascading effects of affective polarization, offering insights
for strategies to mitigate polarization.
