  Online conversations can go in many directions: some turn out poorly due to
antisocial behavior, while others turn out positively to the benefit of all.
Research on improving online spaces has focused primarily on detecting and
reducing antisocial behavior. Yet we know little about positive outcomes in
online conversations and how to increase them-is a prosocial outcome simply the
lack of antisocial behavior or something more? Here, we examine how
conversational features lead to prosocial outcomes within online discussions.
We introduce a series of new theory-inspired metrics to define prosocial
outcomes such as mentoring and esteem enhancement. Using a corpus of 26M Reddit
conversations, we show that these outcomes can be forecasted from the initial
comment of an online conversation, with the best model providing a relative 24%
improvement over human forecasting performance at ranking conversations for
predicted outcome. Our results indicate that platforms can use these early cues
in their algorithmic ranking of early conversations to prioritize better
outcomes.
