When David Petraeus visited the Harvard Kennedy School in 2009, one of the meetings he requested was with author Doris Kearns Goodwin. Petraeus, who holds a PhD in International Relations from Princeton, is a fan of Team of Rivals and wanted time to speak to the famed historian about her work. Apparently, the great general (and current CIA Director) is something of a bibliophile.

He’s increasingly an outlier. Even as global literacy rates are high (84%), people are reading less and less deeply. The National Endowment for the Arts has found that “[r]eading has declined among every group of adult Americans,” and for the first time in American history, “less than half of the U.S. adult American population is reading literature.” Literacy has been improving in countries like India and China, but that literacy may not translate into more or deeper reading.

This is terrible for leadership, where my experience suggests those trends are even more pronounced. Business people seem to be reading less — particularly material unrelated to business. But deep, broad reading habits are often a defining characteristic of our greatest leaders and can catalyze insight, innovation, empathy, and personal effectiveness.

Note how many business titans are or have been avid readers. According to The New York Times, Steve Jobs had an “inexhaustible interest” in William Blake; Nike founder Phil Knight so reveres his library that in it you have to take off your shoes and bow; and Harman Industries founder Sidney Harman called poets “the original systems thinkers,” quoting freely from Shakespeare and Tennyson. In Passion & Purpose, David Gergen notes that Carlyle Group founder David Rubenstein reads dozens of books each week. And history is littered not only with great leaders who were avid readers and writers (remember, Winston Churchill won his Nobel prize in Literature, not Peace), but with business leaders who believed that deep, broad reading cultivated in them the knowledge, habits, and talents to improve their organizations.

The leadership benefits of reading are wide-ranging. Evidence suggests reading can improve intelligence and lead to innovation and insight. Some studies have shown, for example, that reading makes you smarter through “a larger vocabulary and more world knowledge in addition to the abstract reasoning skills.” Reading — whether Wikipedia, Michael Lewis, or Aristotle — is one of the quickest ways to acquire and assimilate new information. Many business people claim that reading across fields is good for creativity. And leaders who can sample insights in other fields, such as sociology, the physical sciences, economics, or psychology, and apply them to their organizations are more likely to innovate and prosper.

Reading can also make you more effective in leading others. Reading increases verbal intelligence (PDF), making a leader a more adept and articulate communicator. Reading novels can improve empathy and understanding of social cues, allowing a leader to better work with and understand others — traits that author Anne Kreamer persuasively linked to increased organizational effectiveness, and to pay raises and promotions for the leaders who possessed these qualities. And any business person understands that heightened emotional intelligence will improve his or her leadership and management ability.

Finally, an active literary life can make you more personally effective by keeping you relaxed and improving health. For stressed executives, reading is the best way to relax, as reading for six minutes can reduce stress by 68%, and some studies suggest reading may even fend off Alzheimer’s, extending the longevity of the mind.

Reading more can lead to a host of benefits for business people of all stripes, and broad, deep reading can make you a better leader. So how can you get started? Here are a few tips:

Join a reading group. One of my friends meets bimonthly with a group of colleagues to read classics in philosophy, fiction, history, and other areas. Find a group of friends who will do the same with you.

One of my friends meets bimonthly with a group of colleagues to read classics in philosophy, fiction, history, and other areas. Find a group of friends who will do the same with you. Vary your reading. If you’re a business person who typically only reads business writing, commit to reading one book this year in three areas outside your comfort zone: a novel, a book of poetry, or a nonfiction piece in science, biography, history, or the arts.

If you’re a business person who typically only reads business writing, commit to reading one book this year in three areas outside your comfort zone: a novel, a book of poetry, or a nonfiction piece in science, biography, history, or the arts. Apply your reading to your work. Are you struggling with a problem at work? Pick up a book on neuroscience or psychology and see if there are ways in which you can apply the lessons from those fields to your profession.

Are you struggling with a problem at work? Pick up a book on neuroscience or psychology and see if there are ways in which you can apply the lessons from those fields to your profession. Encourage others. After working on a project with colleagues, I’ll often send them a book that I think they’ll enjoy. Try it out; it might encourage discussion, cross-application of important lessons, and a proliferation of readers in your workplace.

After working on a project with colleagues, I’ll often send them a book that I think they’ll enjoy. Try it out; it might encourage discussion, cross-application of important lessons, and a proliferation of readers in your workplace. Read for fun. Not all reading has to be developmental. Read to relax, escape, and put your mind at ease.

Reading has many benefits, but it is underappreciated as an essential component of leadership development. So, where have you seen reading benefit your life? What suggestions would you have for others seeking to grow their leadership through reading?