Still working through my data (good grief there is a lot of it), but this one stuck out.
Very few of the demographics seem to have any correlation with ratings in general, how many books one reads per year, what format those books come in, or where you source them. But one of the questions was 'are you an author', which I asked specifically to try to find out if authors, in general, are softer (i.e. higher) raters than most people. Turns out they're not, there's no correlation at all.
Also turns out, authors read about half as many books per year than the rest of the respondents.
I could write a big long full of maths post about why this result is valid, when the very similar gender one wasn't, but for this result, there's about a 98.6% chance it's not random. Anything over 95% confidence is at least reportable for psychology, if not necessarily useful, and 98.6% is waaay over 95%, it's relatively a very strong result.
It's interesting to think about why that might be so. Anecdotally, many authors are pretty vocal about reading being a great (or even the only) way to learn your craft - in fact I'm listening to an audiobook on my breaks right now on the topic, about how to read like a writer. On the other hand, I've seen authors disclaiming that reading too ferociously, especially within genre, can lead to losing one's own voice, and consciously or not aping other writers style. And others point out, quite fairly, that many writers and particularly those fitting it in around day jobs, don't have much time over and would rather spend it writing than reading.
I've also seen authors protesting that "we're readers too", when author vs. reader clashes happen, and that may be true. But they're certainly not as much readers as the rest of the book reviewing community.
On the other other hand (apparently I am Kali today), an average of 66 books a year still puts the author-respondent to my survey pretty far ahead of the curve when it comes to the rest of the world, who often don't care about books in the slightest. So, not judging, just saying: Interesting result, even if I'm not sure what it means.