Obviously, with writers, the inner life of the mind is considered important. I would say, that the level of interest writers have in the real world may vary from writers who are keenly interested in the ordinary external realms of social relations and facts.
People know that nonfiction can be education or entertainment. Fiction is usually either entertainment or ‘edutainment’. Fiction is also medicine to alleviate some of the trouble of dealing with real life. Too much turns into unhealthy escapism but the right amount brings some relief and activity for the mind beyond one’s own inner worlds.
Writers tend to be along the creative end of the spectrum, but if they make their money writing instruction manuals for products it may not seem that way.
There may be some truths that go into creating author stereotypes but I’m not sure they are liable to any more or less true than other stereotypes.
Authors have days when they need external privacy and to get more intimate with fictional characters who they themselves hope will never be real in the usual sense, but known as the fictional beings they are would be okay. Authors also have days when what really matters to them is to be social in real life with good personal relationships. So, don’t be surprised if you meet an author desperately interested in the real world as an escape from the amount of fiction with which he or she has been involved. The same person, may also want to do only a little in real life but work on a pretend story on a different day. I have no real statistical information regarding whether or not authors are more, equally or less weird than say, thespians or computer programmers.