People use less information than they think to make up their minds

Klein and O'Brien (open access, ) note another of our psychological biases or shortcomings. We perform Manichean good or bad characterizations with much less information than we imagine:

Significance

People readily categorize things as good or bad, a welcome adaptation that enables action and reduces information overload. The present research reveals an unforeseen consequence: People do not fully appreciate this immediacy of judgment, instead assuming that they and others will consider more information before forming conclusions than they and others actually do. This discrepancy in perceived versus actual information use reveals a general psychological bias that bears particular relevance in today’s information age. Presumably, one hopes that easy access to abundant information fosters uniformly more-informed opinions and perspectives. The present research suggests mere access is not enough: Even after paying costs to acquire and share ever-more information, people then stop short and do not incorporate it into their judgments.

Abstract

A world where information is abundant promises unprecedented opportunities for information exchange. Seven studies suggest these opportunities work better in theory than in practice: People fail to anticipate how quickly minds change, believing that they and others will evaluate more evidence before making up their minds than they and others actually do. From evaluating peers, marriage prospects, and political candidates to evaluating novel foods, goods, and services, people consume far less information than expected before deeming things good or bad. Accordingly, people acquire and share too much information in impression-formation contexts: People overvalue long-term trials, overpay for decision aids, and overwork to impress others, neglecting the speed at which conclusions will form. In today’s information age, people may intuitively believe that exchanging ever-more information will foster better-informed opinions and perspectives—but much of this information may be lost on minds long made up.