Social influence[1] bias refers to the phenomenon where people’s decisions or actions are swayed by the opinions or behaviors of others, particularly in an online setting. This bias is often seen in online reviews or ratings, where the initial opinions can significantly shape subsequent reviews. This herd behavior can impact the credibility and accuracy of online reviews, leading to a skewed distribution of ratings. A study by Muchnik, Aral, and Taylor found that positive manipulation increased the likelihood of up-voting and higher mean ratings. On the other hand, negative manipulation didn’t significantly alter the final ratings. This bias can also extend to social media[2] platforms, influencing user perceptions and reinforcing ideologies. Understanding and addressing social influence bias is essential for accurate interpretation of online reviews and for mitigating its impact on public opinion.
The social influence bias is an asymmetric herding effect on online social media platforms which makes users overcompensate for negative ratings but amplify positive ones. Positive social influence can accumulate and result in a rating bubble, while negative social influence is neutralized by crowd correction. This phenomenon was first described in a paper written by Lev Muchnik, Sinan Aral and Sean J. Taylor in 2014, then the question was revisited by Cicognani et al., whose experiment reinforced Munchnik's and his co-authors' results.