Too Much Crystallized Thinking Lowers Fluid Intelligence

In a digital age—that puts a premium on facts, figures, and data—crystallized intelligence has become disproportionately valued over fluid intelligence. A wide range of new studies is finding that motor skills, hand-eye coordination, aerobic conditioning, and daily physicality are important for maintaining working memory and fluid intelligence.

Fluid intelligence is the capacity to think logically and solve problems in novel situations, independent of acquired knowledge. Fluid intelligence involves the ability to identify patterns and relationships that underpin novel problems and to extrapolate these findings using logic.

On the other hand, crystallized intelligence is the ability to utilize information, skills, knowledge, and experience in a way that could be measured on a standardized test. Crystallized intelligence represents your lifetime of cerebral knowledge, as reflected through your vocabulary, general explicit knowledge, and Trivial Pursuit-types of declarative memory of people, places, and things.

Although there is some controversy and debate on the best ways to improve fluid intelligence, studies are showing a strong link between non-academic pursuits and improved fluid intelligence. I have written a wide range of Psychology Today blog posts about improving cognitive function through physical activity, playing a musical instrument, making art, improving motor skills, meditation, daydreaming, and getting a good night's sleep. The ultimate goal of The Athlete’s Way is to identify daily habits that optimize the function of the brain, body, and mind throughout a person’s lifespan.

Many experts believe that one of the backlashes of overemphasizing standardized testing as part of "no child left behind" is that young Americans are gaining crystallized intelligence at the expense of their fluid intelligence. As the father of a 6-year-old, I am determined to encourage my daughter to flex both her crystallized intelligence and fluid intelligence every day and would encourage other parents to do the same.

I hated school when I was growing up and did terribly on standardized tests. My SAT scores were barely above average. My older sister, on the other hand, literally got double 800s on her SATs and was a national merit scholar. Throughout my childhood, the unspoken family framework was that my older sister had the "book" smarts, and I had the "athletic" smarts. I never had a chip on my shoulder because I didn’t like reading books or being in school. I wanted to be outside playing, listening to music, or just hanging out with friends. How was your "intelligence" categorized by your parents and teachers when you were growing up?

My father was a neuroscientist and a neurosurgeon and often got frustrated with me for not flexing my "cerebral" muscle. Once I got really into sports and decided to become a professional athlete, he would regularly say things to me like “Chris, there’s a big part of your brain that you’re forgetting to flex and it’s going to shrink.”

In my dad’s eyes, the cerebrum was the seat of cerebral, or intellectual thinking and the cerebellum was the seat of "cerebellar" implicit knowledge and muscle memory. If I didn’t flex my prefrontal cortex and gain new explicit knowledge, he believed that my cerebrum would lose volume and connectivity. To a degree, he was probably right. I realize now the ideal is to maintain a healthy balance of all four brain hemispheres by creating daily habits that engage both crystallized and fluid intelligence throughout your lifespan.

Hampshire College: Non Satis Scire

The main reason I went to Hampshire College is that they don’t have tests or grades. The second reason I went to Hampshire College was because with my SAT scores, I didn’t get in anywhere else. I applied to Hampshire because I didn’t think it would require much cerebral muscle.

What I realize now because of all the research I do on neuroscience and peak performance is that at Hampshire, the neural volume and connectivity of my cerebellum was benefitting from all the running, biking, swimming, meditation, yoga, and art-making I was doing regularly. The fact that I never had to cram my head full of crystallized facts actually fortified my fluid intelligence. Yes, because I never had to take a test or memorize anything, my crystallized intelligence is far below average but my fluid intelligence is probably above average.

The motto of Hampshire College is "Non Satis Scire," which means “to know is not enough." The philosophy is that crystallized intelligence doesn’t really get you that far in the real world—especially in the age of Google. Hampshire wanted to teach us fluid intelligence and emphasized the importance of every individual filtering crystallized information through his or her very unique lens and connecting the dots in new and original ways.

Fluid intelligence is directly linked to creativity and innovation. The book smarts of crystallized intelligence can only take a person so far in the real world. Depriving children of recess and forcing them to sit still in a chair cramming for a standardized test literally causes their cerebellum to shrink and lowers fluid intelligence.

The “Super 8” Fluid Intelligence Loop Connects All Four Brain Hemispheres

Like every son, I craved my father’s approval and wanted him to be proud of me. Even after I broke a Guinness World Record, I felt that in my father’s eyes, I still wasn’t enough. I grew up thinking that my dad sort of considered me a "dumb jock" or "hippie." So, I decided that I was going to get a book deal and publish a book about sports and neuroscience.

My dad published a book called Fabric of Mind in the 1980s. I knew that of all his accomplishments, publishing a book with Viking was the one he boasted about the most. I knew that the key to getting a book deal was to get a good agent, so I set out to find an agent. Jonathan Cane, who got me started as a competitive athlete back in the '80s—and is my founding co-partner at City Coach—was working on a book with an agent named Giles Anderson and connected me with the Anderson Literary Agency. Giles is an amazing agent and got me a book deal with St. Martin’s Press to write The Athlete’s Way: Sweat and the Biology of Bliss.

My father was so impressed that I had gotten a book deal with a major publisher and it really changed our relationship. Finally, for the first time in my life, I had earned his approval. There’s something really sad about that. How much did it take to make me worthy of love and belonging in his eyes? Ack. But anyway...

Over the next two years, my father and I spoke almost every day and I picked his brain for everything that he knew about neuroscience. It was a perfect father-son partnership because my athletic perspective on everything actually informed his thinking and we came up with the idea of shifting the focus of left brain-right brain to a new model of up brain-down brain between the cerebrum and cerebellum. The cerebrum being the "conscious" book brain, and the cerebellum being the "subconscious" muscle memory brain.

At the time, I was trying to say that "left brain-right brain" was wrong and that the salient divide in the cranial globe was not east-west, but north-south between the "up brain" (cerebrum) and "down brain" (cerebellum). I realize now I may have been half right. My hypothesis now is that all four hemispheres need to work together to optimize brain connectivity. Again, this seems so obvious. I don't know why it took me so long to connect the dots.

The most recent neuroscientific research has confirmed that there really is a difference between the left and right hemispheres. But I believe the goal for optimal brain connectivity isn’t just across the corpus callosum of the cerebral hemispheres. Optimal brain function needs to include connectivity of the cerebellar hemispheres via the vermis (which divides the cerebellum) and the midbrain which connects the "big brain" (cerebrum) with the "little brain" (cerebellum).

Beyond that, I have a hunch that when the two hemispheres of the cerebrum and the two hemispheres of the cerebellum become a "superfluid" entity with zero friction and zero viscosity, your mind breaks free to another dimension of consciousness. When every cell of your brain, body, and mind are acting in perfect unison, you are in a state of what I call superfluidity.

That split-brain model became the foundation of The Athlete’s Way. A few years later, when I was working on a proposal for a book called Origins of Imagination, I started to notice that creative greats tended to make some type of physical activity a part of their daily routine. I also noticed that the "eureka" moments often happened when the researcher, artist, or writer had stepped away from the microscope, canvas, or typewriter. The "a-ha" moments happened when a creative person was moving our doing something that used implicit, cerebellar memory.

I also knew that as a writer, I was similar to Joyce Carol Oates in that when I ran, I could visualize and rework entire paragraphs, structure subheadings, and connect new ideas in a way that I couldn’t when I was just sitting still. But what was the neuroscience of this? I was kind of stumped until one day I was walking home and bumped into my friend Maria on Commercial Street in Provincetown. Maria is a poet. I told her about all the research I was doing on the daily habits of creative people and how physical activity was key to creating "superfluidity" of thinking.

Without missing a beat, Maria looked at me and said, “I ride the elliptical trainer for at least 40 minutes every day. When I start moving my arms and legs back and forth, the poetry just starts to come out of me.” As she moved her arms and legs to emulate riding the elliptical, suddenly I realized that the bipedal motion was engaging all four hemispheres and that connectivity optimized brain function and led to fluid intelligence.

I ran home and drew this diagram of the two hemispheres of the cerebrum and the two hemispheres of the cerebellum working together in what I call a "Super 8 Fluid Intelligence Loop." When you bring the cerebellum into the creative or "intellectual" process, crystallized thinking becomes more fluid (or superfluid on a good day).

Fine-Tuned Motor Skills Linked to Fluid Intelligence

On December 23, 2013, researchers in Switzerland announced that they had discovered that humans with higher “motor excitability”—which is linked to fine-tuned motor skills—have a better working memory, which is linked to improved fluid intelligence.

Researchers from the Psychiatric University Clinics (UPK Basel) and the Faculty of Psychology in Basel have found that the excitability of the motor cortex is directly linked to improved working memory performance. "The motor cortical excitability can be easily studied with transcranial magnetic stimulation," says Nathalie Schicktanz, doctoral student and first author of the study.

In the present study, that included 188 healthy young subjects, the scientists were able to show that subjects with high motor excitability had increased working memory performance as compared to subjects with low excitability. "By measuring the excitability of the motor cortex, conclusions can be drawn as to the excitability of other cortical areas," says Schicktanz.

Over the past few years, I have had my antennae up for any research that could prove this hunch. It’s been very exciting to wake up every morning and see cutting edge research confirming the link between physical activity, motor skills, and improved cognitive function. I am still putting the pieces of this puzzle together but this new study from Switzerland is one more piece towards solving this riddle.

The new study titled “Motor Threshold Predicts Working Memory Performance in Healthy Humans” was published in December 2013 in Annals of Clinical and Translational Neurology. The research was conducted by scientists from the Transfacultary Research Platform at the University of Basel. By measuring motor excitability, were able to measure general cortical excitability and related working memory and cognitive performance.

Conclusion: The Importance of Maintaining Working Memory Throughout Your Life

My first book was published a few months before my father passed away in 2007. He died of a heart attack reading The New York Times in a reclining chair. When my sister and I went to Florida to empty out his house, we found stacks and stacks of my hardcover book in his study, and copies of the book were scattered throughout the house.

I felt a sense of peace knowing that my father died knowing that I had published a book. I believe that nobody should ever feel a "need for achievement" or drive for perfection in order to feel worthy of love and belonging. This is one reason I object to crystallized intelligence standardized test scores dictating education. It's also why I make sure my daughter understands that making an effort and pouring your heart into something that you love is all that really matters, regardless of whether you get a gold medal, an A+, or no recognition at all.

Interestingly, since my dad's death, I feel as if he "passed the torch" to me. I have such a joyful passion for carrying on his legacy as a neuroscientist. I wake up every morning eager to see what researchers around the world are discovering how the brain works and sharing that with the general reader. As a neuroscientist, my father grew frustrated with the limitations of brain imaging technology. Although there is still a long way to go, he would be thrilled to see the advances made by things like the connectome project.

People of all ages need to keep their working memory strong in order to maintain fluid intelligence. In a sedentary digital age full of standardized testing, crystallized intelligence is monopolizing our brains and causing some regions to shrink and become disconnected.

It causes me great concern for myself and my daughter's generation that people—especially children—are totally out of balance between crystallized and fluid intelligence. The book proposal I’m working on now is called “SUPERFLUIDITY: Daily Habits That Optimize Brain Connectivity for a Lifespan of Health, Happiness, and Personal Bests” and is geared towards upping the fluid intelligence quotient for people from all walks of life and generations.

If you’d like to read more on this topic, check out my Psychology Today blog posts:

• "The Neuroscience of Imagination"
• “Hand-Eye Coordination Improves Cognitive and Social Skills”
• "Can Physical Activities Improve Fluid Intelligence?"