A question about the content of biographical entries in Wikipedia

Are biographical entries in Wikipedia written by their subjects? Doing so would be a way of getting content that is not subject to copyright, but it would be nice to have it somewhere admitted if this is what is happening. A piece of evidence that this is happening is when the subject writes in the first person, and the Wikipedian who posts it fails to fully convert it to the third person, as apparently happened in the case of this wonk for the pharmaceutical industry, where ‘am an elected Fellow of the’ occurs in the entry on this individual.
keywords: sourcing, editing, TOPICAL