  Does engagement with opposing views help break down ideological `echo
chambers'; or does it backfire and reinforce them? This question remains
critical as academics, policymakers and activists grapple with the question of
how to regulate political discussion on social media. In this study, we
contribute to the debate by examining the impact of opposing views within a
major climate change skeptic online community on Reddit. A large sample of
posts (N = 3000) was manually coded as either dissonant or consonant which
allowed the automated classification of the full dataset of more than 50,000
posts, with codes inferred from linked websites. We find that ideologically
dissonant submissions act as a stimulant to activity in the community: they
received more attention (comments) than consonant submissions, even though they
received lower scores through up-voting and down-voting. Users who engaged with
dissonant submissions were also more likely to return to the forum. Consistent
with identity theory, confrontation with opposing views triggered activity in
the forum, particularly among users that are highly engaged with the community.
In light of the findings, theory of social identity and echo chambers is
discussed and enhanced.
