How our bodies shape our thoughts

The way we perceive the world is often deeply linked to the bodies we move through our surroundings in.

(Photo By Andrea Yepez/millennium images, uk)

When I was aged three or four, my parents took me to Colorado and were excited to show me – a native New Yorker – the magnificent Rocky Mountains. I was, in my dad’s retelling, unimpressed. “I’ve seen mountains like that in Central Park,” I apparently replied.

When you’re only a metre tall, the subtle slopes of Manhattan are as imposing as the Rockies. It’s an intuitive concept: many of us have returned to places we knew as children and found them to be not quite as we remembered. That field, it turns out, is really a garden. The castle is in fact a house.

It’s not only our relative size that affects how we see our surroundings, argue Dennis Proffitt, a professor of psychology at the University of Virginia, and Drake Baer, a journalist, in their new book Perception: How Our Bodies Shape Our Minds. It’s an array of factors ranging from our physical capacities and confidence, to our age, energy levels, social identity and mood.

“We are each living our own version of Gulliver’s Travels, where the size and shape of the objects and people we see are scaled to the size of our body and our ability to interact with our surroundings,” they write. Even optical illusions – which are surprisingly common – help us navigate our environments, giving us a customised world-view that matches our unique abilities.

In one of his experiments, Proffitt had students from the University of Virginia stand at the bottom of a low hill and try to determine the angle of its slope. His subjects tended to drastically overestimate, guessing that the hill – which in reality formed a 5-degree angle with the ground – had a much steeper 20-degree slant. Student athletes, however, – such as the super-fit women on the college soccer team – tended to make more accurate guesses and Proffitt wondered: “Could fitness, or more generally how easy or difficult it is to physically ascend a hill, shape the way that you see it?”

Proffitt’s suspicion grew when he found that people weighed down by a heavy backpack saw the hill as steeper, as did joggers exhausted by a long run. (Standing next to a supportive friend, meanwhile – or even just thinking about one – made the hill appear smaller; similarly, holding a partner’s hand can make a burst of heat on the skin feel less painful.)

“The job of conscious perception isn’t to give you an objectively accurate view of the world but rather to help you make practical decisions about what to do,” Proffitt and Baer write. “We see slopes scaled to the bioenergetic costs of locomotion.” The hills of Central Park would have looked giant to four-year-old me not just because I was comparatively small, but because they would have been difficult for me to climb.

Proffitt and Baer are proponents of “embodied cognition”: consciousness, they believe, does not spring forth from our brains, but is enmeshed with – and profoundly influenced by – our bodies. The debate over the link between mind and body dates back to ancient times, but in the past few decades, cognitive scientists have contributed a wealth of empirical research on the topic.

One of the first champions of embodied cognition was the linguist George Lakoff, whose 1980 book Metaphors We Live By introduced the idea that words are meaningful because we connect them to physical experiences and actions. “When reading about transferring responsibilities, the muscles in our hands will make very subtle movements in much the same way as when reading about transferring objects, like putting away the dishes,” write Proffitt and Baer. Vivid writing and rhetoric is often “imagistic”, tying abstract concepts to sense-memories we can almost feel – and may in fact be re-enacting in our brains. “Brain imaging studies have found that the corresponding motor cortex areas for the foot, hand or tongue will activate when you read about kicking, picking or licking.”

The academic research collected in Perception is all very interesting – but for a lay reader, what does it add up to? I closed the book with a new appreciation for the interconnection between the mind and the body, and I was intrigued, too, by the real-life implications of embodied cognition.

One study convinced me that body-awareness can help us make better decisions in high-pressure situations. In 2012, a team of psychologists led by Sarah Garfinkel recruited a group of male hedge-fund traders from London – their jobs entailed routinely processing reams of complex financial data while millions of pounds hung in the balance. Garfinkel wondered whether “interoception” – the sense of our internal states – played a role in their split-second decision-making.

“It’s an interoceptive signal at work when you realise that your stomach is full and you should stop eating or that your bladder is full and you need to empty it,” Proffitt and Baer explain. Garfinkel set the traders a “heartbeat detection task” used to measure interoception: without touching their wrist, chest or any other pulse point, they had to try to count how many times their heart beat in a 20-50-second period. (Meanwhile, a monitor provided researchers with the real number.) The results were clear: the traders made more accurate guesses than laypeople, and higher-earners did better than their less successful colleagues. The ability to listen to their bodies – to their gut instincts – appeared to help them thrive on a high-stakes, fast-paced trading floor.

For those of us who have never set foot on a trading floor – or who, stuck at home during the pandemic, have an abundance of time – a strong interoceptive sense can still be useful. Garfinkel has linked the ability to detect your heartbeat to various markers of mental well-being, including low anxiety and high-quality sleep.

After reading this chapter, I attempted to complete the heartbeat detection task myself; maybe my heartbeat held the key to happiness. I closed my eyes and sat still, imagining my heart pumping blood around my body. I counted silently, surprised at how easy it was, before realising I was probably just listening to a clock ticking in the next room. I couldn’t check the accuracy of my counting without touching my wrist – but the quiet act of trying to listen to my body and engage my intero- ceptive signals, was meditative and calming in itself.

Perception: How Our Bodies Shape Our Minds
Dennis Proffitt and Drake Baer
St Martin’s, 304pp, £23