The IQ test is the best measure of intelligence that we have. However, looking at someone’s library can provide a significant insight into their level of intelligence, assuming that they read the books in their library.
When I was in my early 20’s, I spent a month with my Uncle Richard who lived in San Jose, California. At cocktail hour, I would sit in his library, listening to him play Chopin or Bach on his grand piano while I scanned the diverse array of books that populated the many shelves that enveloped us. The plays of Shakespeare, well-worn from many readings, classic literature from ancient and modern authors, and books on philosophy invited reading on all the topics that excite inquiring minds. He introduced me to Wittgenstein’s Tractatus that extended my interest in mathematics to its logical foundations. His discussions of quantum physics and its interpretations revealed an interest in anything dealing with abstract thought and he supported his learning by surrounding himself with colleagues from the university where he taught art history. He seldom mentioned that he had a Ph.D. from Harvard, but his high IQ was evident in his articulation of concepts and from an observation of his library.
In the decades that followed, I observed many people and scanned their libraries, curious about their reading interests and searching for areas in which they had some expertise that I could mine for gold. As computers and e-books entered the scene, extensive libraries became less prominent, but most high IQ people I knew tended to have lots of books, including textbooks from their college days.
At the other end of the scale, I have visited people who didn’t collect many books. They read mainly magazines, light novels or popular best-sellers that they would dispose of once they were read. Some of these people I would judge to have a high IQ based on other indicators, such as their judgements in business transactions. In spite of their high intelligence, they were not academically inclined.
Among those whom I would judge to have low IQ, based on my personal judgment of their level of awareness and life trajectory, rarely showed much interest in reading. I never found such a person to have a book on physics, mathematics, computer programming or philosophy sitting on their coffee table. Such people seemed to have little interest in anything other than the here and now. It would be difficult to imagine them looking at the night sky and reflecting on the vast galaxies in the universe.
These observations may sound pompous or self-promotional to someone who is not into reading, but they are the general observations of a person whose motivation to read comes from an awareness of his ignorance. As Mark Twain observed, “We are all ignorant; just about different things.” The books a person reads may not be a measure of their IQ, but there is probably a moderate to strong correlation.
