In one of the experiments, the subjects were asked to read a short story about a student who had to overcome a series of obstacles to vote in an election. The readers who'd most closely identified with the character became far more likely to vote in the United States presidential election, held a few days later.
For the influence to work, the reader has to deeply identify with the character, and feel the character's emotions, thoughts, beliefs and internal responses as their own. The researchers called this phenomenon "experience-taking".
"Experience-taking can be a powerful way to change our behaviour and thoughts in meaningful and beneficial ways," said Lisa Libby, co-author of the study and assistant professor of psychology at Ohio State University.
The effect was more pronounced when the subject was reading a version of the story written in first person ("I entered the voting booth") than when it was in third person ("Paul entered the voting booth"). It was also stronger when the character in the story was a student who attended the same university as the readers, compared with a character from a different university.
For the effect to work, the reader also needed to be able to put aside his or her own identity - the spell of influence was broken when the researchers put readers into a cubicle with a mirror in it.
"Experience-taking changes us by allowing us to merge our own lives with those of the characters we read about, which can lead to good outcomes," said Geoff Kaufman, who led the study.
"The more you're reminded of your own personal identity, the less likely you'll be able to take on a character's identity.
"You have to be able to take yourself out of the picture, and really lose yourself in the book in order to have this authentic experience of taking on a character's identity."
Other experiments found that readers were more likely to adopt liberal attitudes to sexual orientation and race after becoming absorbed in stories that featured a character of a different race or orientation - but only if they discovered late in the story that the character was different from them, so they had time to channel that person first.
Libby said experience-taking was different from perspective-taking, where people can understand what a character is going through but don't lose sight of their own identity.
"Experience-taking is much more immersive - you've replaced yourself with the other," she said.
"Experience-taking can be very powerful because people don't even realise it is happening to them. It is an unconscious process."
She said the effect could last for days.
I'm off to read The Hunger Games. The things I could do with a bit more Katniss Everdeen in me...
Have you ever experienced this? What character would you like to channel?