Intellectual Wellness
To earn a license, a London taxi driver memorizes roughly 25,000 streets, a training drivers call the Knowledge. In 2000, Eleanor Maguire's group at University College London scanned the brains of 16 licensed drivers and compared them with men who did not drive taxis. The drivers had larger posterior hippocampi, a region involved in spatial memory, and the longer a man had driven a cab, the larger that region was.
The study compared two groups at one point in time, so it could not show that the job enlarged the region. Because volume rose with years of driving, Maguire's group argued that it did.
What it covers
Intellectual wellness is the difference between taking in information and thinking it through. It has little to do with IQ. It rests on four things.
Curiosity
Following a question because it interests you, whether or not it leads anywhere.
Learning
Staying with a new skill through the clumsy beginner stage.
Focus
The capacity for long stretches of concentrated thought.
Range
Reading outside your usual lane, including arguments you disagree with.
One of my stronger dimensions
Intellectual is one of my stronger dimensions. Curiosity pulled me into academic medicine, then into integrative medicine, and it keeps pulling me back to the microbiome. Every step was me following the next question I couldn't stop asking.
One of those questions came on a cross-country drive. Somewhere on a flat stretch of I-80, I could not stop thinking about telomeres, the repeating caps on the ends of chromosomes, and why a cell would keep them. I missed half the scenery. Nearly two decades later, Elizabeth Blackburn, Carol Greider, and Jack Szostak shared the 2009 Nobel Prize for showing how telomeres and the enzyme telomerase protect chromosomes.
At midlife, curiosity met a harder test when I decided to learn guitar. On my first barre chord, where one finger holds down all six strings, my hand cramped within thirty seconds and my thumb ached. The sound that came out was an audible cry for help. I set the guitar down. Then I came back to it a few minutes at a time, and slowly the sound turned into an actual chord.
What the research measures
In a study run by Denise Park's group at the University of Texas at Dallas, 221 adults aged 60 to 90 completed three months of learning digital photography, quilting, or both, at about 16 hours a week. Comparison groups spent the same time in social activities that involved no new learning, or on low-demand tasks at home. Episodic memory improved more in the groups learning a demanding new skill, most clearly in the groups that included photography. Quilting alone did not reach statistical significance. The social group, somewhat to the researchers' surprise, gained little. The results appeared in Psychological Science in 2014.
At UC Davis, Matthias Gruber and Charan Ranganath had volunteers rate how curious they were about the answers to trivia questions, then scanned them while they waited for the answers. People remembered more of the answers they were curious about, and they also remembered more of the unrelated faces shown to them during the wait. During high curiosity, activity rose in the midbrain and the nucleus accumbens, regions tied to reward, and the people whose memory for the faces improved most showed the most tightly coupled activity between the midbrain and the hippocampus.
Listen and read
Podcast. Wellness, Rewired, Episode 3: The Intellectual Dimension
Essay. Why Learning Badly Might Be the Smartest Thing You Do
The Well-IQ assessment is free and takes about 15 minutes. It scores Intellectual alongside the other eight dimensions.
Educational content, not medical advice.