Bias and Democracy
SOCIAL KNOWLEDGE IMPROVES collective decision making only if new information changes minds. But internal bias presents an important obstacle to updating on the basis of external evidence of the world. Indeed, some political scientists and psychologists believe bias is so pervasive that little if any updating takes place in politics. If bias prevents more information from modifying electoral outcomes, better deployment of information technology and better information-eliciting rules will not help solve problems of governance.
A host of biases infect political decision making. Nevertheless, even now these pervasive biases do not present an insuperable obstacle to democratic updating. The fundamental building blocks of a modern democratic system, from voting rules to the nature of representation, constrain bias by economizing on the number of people who need to update and by providing incentives to key players to temper their biases.
Bias represents a departure from rational updating on the evidence. People are biased in their daily lives even apart from politics, and psychologists have cataloged these biases in a systematic way. But whatever the departures from rational updating in daily life, it would be extravagant to deny that updating routinely takes place. It is an axiom of cognitive science that people often change their minds in the face of new information,1 even if biases and cognitive limitations make such updating imperfect. Experiments suggest that individual decisions are often better when there is better access to information and facts.2
Evolution offers the most powerful proof that innate biases are not so substantial that they preclude updating. If humans did not rationally act on evidence, they would be less likely to make it to reproductive age.3 Failing to update would make it likelier that one would miss the opportunity to trap an animal for one’s meal or avoid the predator behind a tree.