Why do we read fiction? Why do we care so passionately about nonexistent characters? What underlying mental processes are activated when we read? ...The layered process of figuring out what someone else is thinking — of mind reading — is both a common literary device and an essential survival skill. This capacity is termed 'theory of mind' by cognitive psychologists.Experiments are actually planned to perform MRI experiments on subjects exposed to a set of texts of graduated complexity, noting brain areas previously associated with theory of mind operations. Cohen's article notes nother perspective:
Humans can comfortably keep track of three different mental states at a time. For example, the proposition “Peter said that Paul believed that Mary liked chocolate” is not too hard to follow. Add a fourth level, though, and it’s suddenly more difficult. And experiments have shown that at the fifth level understanding drops off by 60 percent. Modernist authors like Virginia Woolf are especially challenging because she asks readers to keep up with six different mental states, or levels of intentionality...Perhaps the human facility with three levels is related to the intrigues of sexual mating. Do I think he is attracted to her or me?
...fictional accounts help explain how altruism evolved despite our selfish genes. Fictional heroes are [frequently] “altruistic punishers,” people who right wrongs even if they personally have nothing to gain. “To give us an incentive to monitor and ensure cooperation, nature endows us with a pleasing sense of outrage” at cheaters, and delight when they are punished. We enjoy fiction because it is teeming with altruistic punishers: Odysseus, Don Quixote, Hamlet, Hercule Poirot...It’s not just that evolution gives us insight into fiction, but also that fiction gives us insight into evolution.