Wouldn't this correlate with people with a bias for action? (both to physically go to a talk, and to take the action of creating something that would cite it)
Also, physically attending a talk shows a very strong interest in a subject, meaning you would probably already be working on some adjacent knowledge.
Indeed. I would suspect that also the talk goes into more detail about some of the less-familiar contributions, which helps with understanding and retention. People won't cite papers if they don't understand them well, and that could happen if they're so dry that the point doesn't come across as easily.
Also, physically attending a talk shows a very strong interest in a subject, meaning you would probably already be working on some adjacent knowledge.