Divergent Effects of Partisanship on Social Information Search and Use

Social information plays a key role in almost all areas of human decision-making, helping individuals reduce uncertainty and improve their decisions. Despite a wealth of research on how people use social information, few studies have focused on the process of searching for social information. Social information search is, however, a key component of social learning. People also do not learn from just anyone, for example, they show preference for their ingroup and actively disregard information from the outgroup. Such a bias can have negative outcomes. Here, we examine how partisanship—known to cause a strong ingroup bias—affects social information search and social information use across four studies. We split the search process into initiation—an initial hurdle to seek out social information—and the extent of search after initiation. We found that partisanship did not affect the quantity of search after initiation, with participants exploring the choices of ingroup and outgroup members equally. However, in an election prediction task, where partisan identity was more salient, participants initiated more social information search from the ingroup. For social information use, participants gave more weight to the choices of ingroup members and weighed social information more if it aligned with their political beliefs. Our findings demonstrate the importance of disentangling social information search and use, highlighting that partisan biases in information processing can emerge at different stages.