sciencemag | Our society is increasingly relying on the digitized, aggregated
opinions of others to make decisions. We therefore designed
and analyzed a large-scale randomized experiment
on a social news aggregation Web site to investigate whether knowledge
of
such aggregates distorts decision-making. Prior
ratings created significant bias in individual rating behavior, and
positive
and negative social influences created
asymmetric herding effects. Whereas negative social influence inspired
users to correct
manipulated ratings, positive social influence
increased the likelihood of positive ratings by 32% and created
accumulating
positive herding that increased final ratings by
25% on average. This positive herding was topic-dependent and affected
by
whether individuals were viewing the opinions of
friends or enemies. A mixture of changing opinion and greater turnout
under
both manipulations together with a natural
tendency to up-vote on the site combined to create the herding effects.
Such findings
will help interpret collective judgment
accurately and avoid social influence bias in collective intelligence in
the future. Fist tap Dale.
