Using the Nested Structure of Knowledge to Infer What Others Know
研究发现人类知识具有嵌套结构：知道少量信息的人通常知道很常见的知识，而罕见知识只有知道很多知识的人才知道。基于此，人们即使对某个主题几乎无知，也能通过对方是否知道一条罕见知识来推断其知识水平。
Humans rely on more knowledgeable individuals to acquire information. But when we are ignorant, how are we to tell who is knowledgeable? We propose that human knowledge is nested: People who know only a few things tend to know very common pieces of information, whereas rare pieces of information are known only by people who know many things, including common things. This leads to the possibility of reliably inferring knowledgeability from minimal cues. In this study ( N = 848 U.S. adults recruited online), we show that individuals can accurately gauge others’ knowledgeability on the basis of very limited information, relying on their ability to estimate the rarity of different pieces of knowledge and on the fact that knowing a rare piece of information indicates a high likelihood of knowing more information in the same theme. Even participants who are largely ignorant of a theme can infer how knowledgeable other individuals are on the basis of the possession of a single piece of knowledge.