Social Influence Bias: A Randomized Experiment
Lev Muchnik, Sinan Aral and Sean Taylor ran a randomized experiment on a social news aggregation website to test whether seeing others' aggregated opinions distorts individual decisions. Prior ratings created significant bias in individual rating behaviour. Positive and negative social influence produced asymmetric herding: negative influence led users to correct the manipulated ratings, while positive influence increased positive ratings and produced accumulating herding that raised final ratings. The positive herding depended on topic and on whether users saw opinions from friends or from enemies, and the authors attribute the effects to a mix of changed opinions, greater turnout under both manipulations and users' natural tendency to up-vote.
Lev Muchnik, Sinan Aral and Sean Taylor ran a randomized experiment on a social news aggregation website to test whether seeing others' aggregated opinions distorts individual decisions. Prior ratings created significant bias in individual rating behaviour. Positive and negative social influence produced asymmetric herding: negative influence led users to correct the manipulated ratings, while positive influence increased positive ratings and produced accumulating herding that raised final ratings. The positive herding depended on topic and on whether users saw opinions from friends or from enemies, and the authors attribute the effects to a mix of changed opinions, greater turnout under both manipulations and users' natural tendency to up-vote.
Written from the abstract as shown on the PubMed record, read 2026-10-28.
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Muchnik, L., Aral, S., & Taylor, S. J. (2013). Social influence bias: A randomized experiment. Science, 341(6146), 647-651. doi:10.1126/science.1240466 https://doi.org/10.1126/science.1240466