Most of us have been reading since we were very young, but how many of us really think about the “why” behind the words? What makes a novel compelling, or a memoir so riveting? Why do some readers lose themselves in fantasy and sci-fi while others swear by non-fiction instead?

According to Sara Nelson, editor in chief of Publishers Weekly, “Why people read what they read is a great unknown and personal thing.” But while the reasons for reading can’t exactly be dissected, the science behind why readers read - and what happens to our brains when we read - is profoundly interesting.

I read, therefore I am stimulated

We all know more or less how the brain becomes addicted to things. Sometimes lifelong readers read simply because reading makes them feel good, or because it’s familiar. Many famous novelists confess to being steered towards books by a single transformative reading experience during adolescence.

Junot Diaz, author of Pulitzer Prize-winning "The Brief Wondrous Life of Oscar Wao," remembers stumbling upon a mobile library with his family after emigrating from the Dominican Republic to New Jersey. Sherman Alexie, who won the National Book Award for “The Absolutely True Diary of a Part-Time Indian," attributes his romance with reading to "The Snowy Day," a children’s picture book that featured a “brown” character like himself.

Most readers would be able to relate to those stories, but the missing plot component behind each of them is the “why.” Does a lifelong love of reading really just come down to firing endorphins? Not quite. This is where science comes into play.

Your brain on books

The human brain is very creative, and we naturally tend to visualize whatever we think about. While the average reader is no Einstein (who famously performed visual thought experiments that led to all of his breakthroughs), the act of reading naturally triggers complex visualizations. In other words, getting lost in a great book is a highly immersive experience that makes our brains come alive.

In fact, reading about something is the same as experiencing it, at least neurologically-speaking. The same regions of the brain stimulated by the real thing are also stimulated by words. So, while a literary fiction reader may have a harder time suspending disbelief compared to a J.R.R. Tolkien apologist, both readers are having vicarious experiences. Nonfiction readers are just as susceptible: a good memoir or guidebook allows readers to retrace the experiences of the writer in the same way fiction does.

Story structure itself also plays a role in why we start reading and keep reading throughout adult life. A story with a beginning, middle, and end is food for the brain because it makes us think in sequence and links cause and effect. Neuroscientists actually encourage parents to read to their children because it extends attention spans while the brain is growing.

Which begs the question: does the brain react in the same way to other story mediums the same way it does to text? Not quite. Believe it or not, reading has a unique power.

How reading is different from listening or watching

According to one Carnegie Mellon study, reading actually activates brain growth. Participants underwent a six-month reading program and were actually able to increased white matter in the language area of the brain, which could lower the risk of mild cognitive impairment (MCI) associated with Alzheimer’s disease. Critical literary reading can even give the brain a real workout in complex cognitive functions.

In other words, reading can benefit non-readers, too. People who prefer to get their story fix via television or video game narratives can be trained to become better readers, which will help them maintain cognitive ability and increase attention spans over time.

Reading has even been shown to make readers more empathetic. As psychologists from Washington University in St. Louis discovered, “readers mentally simulate each new situation encountered in a narrative.” By doing so, they become “more alert to the inner lives of others.” This would certainly explain why many introverts also happen to be bookworms. Reading not only tickles their fancies in the right way - it also helps them develop sympathetic social skills apart from high-stress social environments.

Reading between the lines

As it turns out, there are plenty of good reasons to read and keep reading. In an age of increasing technological distractions, readers, writers, and publishers alike can find solace in the fact that what they do helps us all stay grounded. It certainly doesn’t hurt that reading makes us smarter, too.

A lifelong love of reading may very well be one of the best habits (or addictions) you’ll ever have.