In the Western tradition, the idea of citing a specific author as a source for an idea did not become common practice until the 17th century. It was often dangerous for authors to be associated with an idea, and while it was preferable for people to cite authorship, it was not common. Before the printing press, books were hand copied by scribes in monasteries, who treated it as a sacred, even spiritual, duty. Books were seen more as storage of ideas than it was for the distribution of ideas. Libraries in monasteries and cathedrals became important sites that stored rare manuscripts.
When the state came in and created the institution of the university, this changed the way that knowledge can be shared and distributed. Following the scientific method, discoveries have to be "proven" with evidence. With the gradual splintering of disciplines into their own domains, education became increasingly segmented and territorial. The variety of disciplines that are part of the social sciences - e.g. anthropology, sociology, psychology, economics, linguistics, political science, etc. - all came under the common umbrella of "philosophy". Before all these disciplines were split and institutionalized into the departments and programs we know of today, they were often discussed under informal settings, not unlike the wikis of today, where knowledge and ideas are shared among peers in salons, clubs, and so on.
The problem of "authorship" has been addressed by many theorists, who argue that no piece of work can have a single author. But the university institute necessitated scholars to go out and disseminate their ideas, through lectures, presentations, and publications, all of which required that somehow their ideas can be called their own.
Historically, we know that this is never the case. Ferdinand de Saussure, the "father" of modern linguistics, was not published, and his ideas might not have been so widely known had his students not taken his lecture notes and created the seminal work Course in General Linguistics. But although this is generally cited under Saussure, these are his students selections and interpretations. The same can be said of collaborations between Marx and Engels.
It is not surprising, then, for many scholars today to view wikis with great suspicion, not only in that they are "unreliable" because any one can edit it, but because the institution of the university puts a premium on "original" work, which must be guarded and held until the last minute to ensure that no one will steal our idea. Wikis (and many internet tools such as blogs) turn this on its head by disrupting the idea of authorship.