A team of researchers at Ohio State University have found that readers of literature "begin spontaneiously assuming the thoughts, behaviours, goals and traits of fictional characters as if they are their own." This is especially true of reading material written in the first person.
Let's look at the specifics. One group of university students read a short story about a person who attended the same university as the group voting despite a number of obstacles. Another group read a similar short story but about someone not at their university. The accounts also varied as to whether they were written in the first person or the third person.
There was an election at the participants' university not long after this. The group who read the first person account of a character who attended their university had a much higher turnout on election day than the others (65% vs. 29%).
I wonder how this applies to writers who immerse themselves in a character as they write a novel or a screenplay. Are there "method" writers who feel the influence of their characters even when they're not writing?
I once was asked whether I wanted to write a screenplay based on the story of a woman who had been held captive and tortured. I turned it down because I didn't want to spend a lot of time immersed in that world--the job would have involved lengthy interviews with the victim who herself had a criminal past, and a number of her associates.
Actually, the producer could tell this wasn't my cup of tea and wouldn't have hired me anyway, he told me after I'd said no. I think his statement was, "These people would eat you alive."
It's not that I can't or don't want to write parts for villains; in fact it's a pleasure because they do tend to be the juiciest characters. However, they've been just one part of the story and I've always been more interested in how they are similar to the "hero" rather than how they are different.
I've also had the opposite effect--that is, I've really enjoyedj spending time with characters I liked and was sad when I finished the screenplay.
Anyway, it's something to watch out for when you immerse yourself in a story. There may be times when you need to consciously leave the characters behind when you get up from your writing desk.
(How did the great writers like Dickens, Austen, Chekvhov, Hemingway and others approach creating vivid characters? You'll find their advice on this in my newest book, "Your Creative Writing Masterclass," published by Nichoals Brealey and available now from Amazon and other booksellers.)