|Solving puzzles: on foot|
To coincide with the release of How to Think About Exercise, I've a piece in The Guardian: 'If exercise was good for Charles Darwin, it's good for all of us'. (Not my title.)
Starting with Charles Darwin's daily walks, I'm talking about the mental rewards of exercise. A sample:
Darwin was not being eccentric: many puzzles are solved on foot. Poet William Wordsworth paced his gravel path, composing rhymes. Novelist Haruki Murakami runs marathons – including the original marathon (albeit backwards), from Athens to the ancient city. It is often written that the citizens of Königsberg set their clocks by the regular walks of philosopher Immanuel Kant. And Friedrich Nietzsche strolled for hours, often around lakes or up mountains. In Sorrento, Italy, he wandered to his Gedankenbaum – his "thought tree".
There are many good reasons for walking and jogging: fitness, health, quiet solitude or conversation, and the stimulation that happenstance affords. But regular footslogging can also enrich our creativity and enhance our character.
Scientists speak of "transient hypofrontality": a state-of-mind promoted by pursuits that require physical exertion but little thought or concentration. The parts of the brain that coordinate general concepts and rules are turned down, while the motor and sensory parts are turned up. In this state, ideas and impressions mingle more freely. Unusual and unexpected thoughts arise.
This is partly why Darwin's son said the naturalist's walks were for his "hard thinking": not simply because he analysed data, but because he allowed his mind to wander as he kicked his stones. He let his idle mind metabolise its massive meals of data. ("I hate a barnacle," he wrote, "as no man ever did before.") Obviously walking was not responsible for Darwin's theory of evolution by natural selection, but a good footslog was certainly part of his cognitive labour – and still is for many today.