Web of lies: a tool for determining the limits of verification in preventing the spread of false information on networks.

The spread of false information on social networks has garnered substantial scientific and popular attention. To counteract this spread, verification of the truthfulness of information has been proposed as a key intervention. Using a novel behavioral experiment with over 2000 participants, we analyze participants' willingness to spread false information in a network. All participants in the network have aligned incentives making lying attractive and countering the explicit norm of truth-telling that we impose. We investigate how verifying the truth, endogenously or exogenously, impacts the choice to lie or to adhere to the norm of truth-telling and how this compares to the spread of information in a setting in which such verification is not possible. The three key take-aways are (1) verification is only moderately effective in reducing the spread of lies, and (2) its effectivity is contingent on the agency of people in seeking the truth, and (3) on the exposure of liars, not only on the exposure of the lies being told. These results suggest that verification is not a blanket solution. To enhance its effectivity, verification should be combined with efforts to foster a culture of truth-seeking and with information on who is spreading lies.