The Nature and Origins of Misperceptions: Understanding False and Unsupported Beliefs About Politics : Nature and Origins of Misperceptions

Human behaviour is thought to spread through face-to-face social networks, but it is difficult to identify social influence effects in observational studies, and it is unknown whether online social networks operate in the same way. Here we report results from a randomized controlled trial of political mobilization messages delivered to 61 million Facebook users during the 2010 US congressional elections. The results show that the messages directly influenced political self-expression, information seeking and real-world voting behaviour of millions of people. Furthermore, the messages not only influenced the users who received them but also the users' friends, and friends of friends. The effect of social transmission on real-world voting was greater than the direct effect of the messages themselves, and nearly all the transmission occurred between 'close friends' who were more likely to have a face-to-face relationship. These results suggest that strong ties are instrumental for spreading both online and real-world behaviour in human social networks.

Substantial constituency influence over the lower house of Congress is commonly thought to be both a normative principle and a factual truth of American government. From their draft constitution we may assume the Founding Fathers expected it, and many political scientists feel, regretfully, that the Framers' wish has come all too true. Nevertheless, much of the evidence of constituency control rests on inference. The fact that our House of Representatives, especially by comparison with the House of Commons, has irregular party voting does not of itself indicate that Congressmen deviate from party in response to local pressure. And even more, the fact that many Congressmenfeelpressure from home does not of itself establish that the local constituency is performing any of the acts that a reasonable definition of control would imply.