  As political polarization in the United States continues to rise, the
question of whether polarized individuals can fruitfully cooperate becomes
pressing. Although diversity of individual perspectives typically leads to
superior team performance on complex tasks, strong political perspectives have
been associated with conflict, misinformation and a reluctance to engage with
people and perspectives beyond one's echo chamber. It is unclear whether
self-selected teams of politically diverse individuals will create higher or
lower quality outcomes. In this paper, we explore the effect of team political
composition on performance through analysis of millions of edits to Wikipedia's
Political, Social Issues, and Science articles. We measure editors' political
alignments by their contributions to conservative versus liberal articles. A
survey of editors validates that those who primarily edit liberal articles
identify more strongly with the Democratic party and those who edit
conservative ones with the Republican party. Our analysis then reveals that
polarized teams---those consisting of a balanced set of politically diverse
editors---create articles of higher quality than politically homogeneous teams.
The effect appears most strongly in Wikipedia's Political articles, but is also
observed in Social Issues and even Science articles. Analysis of article "talk
pages" reveals that politically polarized teams engage in longer, more
constructive, competitive, and substantively focused but linguistically diverse
debates than political moderates. More intense use of Wikipedia policies by
politically diverse teams suggests institutional design principles to help
unleash the power of politically polarized teams.
