Which of the following is NOT a reason for group polarization?

Exposure to newer arguments favoring one's viewpoints. Personal preferences dominating group discussions. Perception of others' viewpoints as ingroup. None of the above

Personal preferences dominating group discussions.

Group polarization is not caused by personal preferences dominating group discussions. Rather, it occurs due to exposure to new arguments favouring one's viewpoints, and the perception of others' viewpoints as ingroup.