  Recent years have witnessed the tremendous growth of the online social media.
In China, Weibo, a Twitter-like service, has attracted more than 500 million
users in less than four years. Connected by online social ties, different users
influence each other emotionally. We find the correlation of anger among users
is significantly higher than that of joy, which indicates that angry emotion
could spread more quickly and broadly in the network. While the correlation of
sadness is surprisingly low and highly fluctuated. Moreover, there is a
stronger sentiment correlation between a pair of users if they share more
interactions. And users with larger number of friends posses more significant
sentiment influence to their neighborhoods. Our findings could provide insights
for modeling sentiment influence and propagation in online social networks.
