All fall down

Talking to Scott Grafton about his book Physical Intelligence (Pantheon), 10 March 2020.

“We didn’t emerge as a species sitting around.”

So says University of California neuroscientist Scott Grafton in the introduction to his provoking new book Physical Intelligence. In it, Grafton assembles and explores all the neurological abilities that we take for granted — “simple” skills that in truth can only be acquired with time, effort and practice. Perceiving the world in three dimensions is one such skill; so is steadily carrying a cup of tea.

At UCLA, Grafton began his career mapping brain activity using positron emission tomography, to see how the brain learns new motor skills and recovers from injury or neurodegeneration. After a career developing new scanning techniques, and a lifetime’s walking, wild camping and climbing, Grafton believes he’s able to trace the neural architectures behind so-called “goal-directed behavior” — the business of how we represent and act physically in the world.

Grafton is interested in all those situations where “smart talk, texting, virtual goggles, reading, and rationalizing won’t get the job done” — those moments when the body accomplishes a complex task without much, if any, conscious intervention.. A good example might be bagging groceries. Suppose you are packing six different items into two bags. There are 720 possible ways to do this, and — assuming that like most people you want heavy items on the bottom, fragile items on the top, and cold items together — more than 700 of the possible solutions are wrong. And yet we almost always pack things so they don’t break or spoil, and we almost never have to agonise over the countless micro-decisions required to get the job done.

The grocery-bagging example is trivial, but often, what’s at stake in a task is much more serious — crossing the road, for example — and sometimes the experience required to accomplish it is much harder to come by. A keen hiker and scrambler, Grafton studs his book with first-hand accounts, at one point recalling how someone peeled off the side of a snow bank in front of him, in what escalated rapidly into a ghastly climbing accident. “At the spot where he fell,” he writes, “all I could think was how senseless his mistake had been. It was a steep section but entirely manageable. Knowing just a little bit more about how to use his ice axe, he could have readily stopped himself.”

To acquire experience, we have to have experiences. To acquire life-saving skills, we have to risk our lives. The temptation, now that we live most of our lives in urban comfort, is to create a world safe enough that we don’t need expose ourselves to such risks, or acquire such skills.

But this, Grafton tells me, when we speak on the phone, would be a big mistake. “If all you ever are walking on is a smooth, nice sidewalk, the only thing you can be graceful on is that sidewalk, and nothing else,” he explains. “And that sets you up for a fall.”

He means this literally: “The number one reason people are in emergency rooms is from what emergency rooms call ‘ground-level falls’. I’ve seen statistics which show that more and more of us are falling over for no very good reason. Not because we’re dizzy. Not because we’re weak. But because we’re inept. ”

For more than 1.3 million years of evolutionary time, hominids have lived without pavements or chairs, handling an uneven and often unpredictable environment. We evolved to handle a complex world, and a certain amount of constant risk. “Very enriched physical problem solving, which requires a lot of understanding of physical relationships, a lot of motor control, and some deftness in putting all those understandings together — all the while being constantly challenged by new situations — I believe this is really what drives brain networks towards better health,” Grafton says.

Our chat turns speculative. The more we removed risks and challenges from our everyday environment, Grafton suggests, the more we’re likely to want to complicate and add problems to the environment, to create challenges for ourselves that require the acquisition of unusual motor skills. Might this be a major driver behind cultural activities like music-making, craft and dance?

Speculation is one thing; serious findings are another. At the moment, Grafton is gathering medical and social data to support an anecdotal observation of his: that the experience of walking in the wild not only improves our motor abilities, but also promotes our mental health.

“A friend of mine runs a wilderness programme in the Sierra Nevada for at-risk teenagers,” he explains, “and one of the things he does is to teach them how to get by for a day or two in the wilderness, on their own. It’s life-transforming. They come out of there owning their choices and their behaviour. Essentially, they’ve grown up.”

Elements of surprise

Reading Vera Tobin’s Elements of Surprise for New Scientist, 5 May 2018

How do characters and events in fiction differ from those in real life? And what is it about our experience of life that fiction exaggerates, omits or captures to achieve its effects?

Effective fiction is Vera Tobin’s subject. And as a cognitive scientist, she knows how pervasive and seductive it can be, even in – or perhaps especially in – the controlled environment of an experimental psychology lab.

Suppose, for instance, you want to know which parts of the brain are active when forming moral judgements, or reasoning about false beliefs. These fields and others rest on fMRI brain scans. Volunteers receive short story prompts with information about outcomes or character intentions and, while their brains are scanned, have to judge what other characters ought to know or do.

“As a consequence,” writes Tobin in her new book Elements of Surprise, “much research that is putatively about how people think about other humans… tells us just as much, if not more, about how study participants think about characters in constructed narratives.”

Tobin is weary of economists banging on about the “flaws” in our cognitive apparatus. “The science on this phenomenon has tended to focus on cataloguing errors people make in solving problems or making decisions,” writes Tobin, “but… its place and status in storytelling, sense-making, and aesthetic pleasure deserve much more attention.”

Tobin shows how two major “flaws” in our thinking are in fact the necessary and desirable consequence of our capacity for social interaction. First, we wildly underestimate our differences. We model each other in our heads and have to assume this model is accurate, even while we’re revising it, moment to moment. At the same time, we have to assume no one else has any problem performing this task – which is why we’re continually mortified to discover other people have no idea who we really are.

Similarly, we find it hard to model the mental states of people, including our past selves, who know less about something than we do. This is largely because we forget how we came to that privileged knowledge.

“Tobin is weary of economists banging on about the ‘flaws’ in our cognitive apparatus”
There are implications for autism, too. It is, Tobin says, unlikely that many people with autism “lack” an understanding that others think differently – known as “theory of mind”. It is more likely they have difficulty inhibiting their knowledge when modelling others’ mental states.

And what about Emma, titular heroine of Jane Austen’s novel? She “is all too ready to presume that her intentions are unambiguous to others and has great difficulty imagining, once she has arrived at an interpretation of events, that others might believe something different”, says Tobin. Austen’s brilliance was to fashion a plot in which Emma experiences revelations that confront the consequences of her “cursed thinking” – a cognitive bias making us assume any person with whom we communicate has the background knowledge to understand what is being said.

Just as we assume others know what we’re thinking, we assume our past selves thought as we do now. Detective stories exploit this foible. Mildred Pierce, Michael Curtiz’s 1945 film, begins at the end, as it were, depicting the story’s climactic murder. We are fairly certain we know who did it, but we flashback to the past and work forward to the present only to find that we have misinterpreted everything.

I confess I was underwhelmed on finishing this excellent book. But then I remembered Sherlock Holmes’s complaint (mentioned by Tobin) that once he reveals the reasoning behind his deductions, people are no longer impressed by his singular skill. Tobin reveals valuable truths about the stories we tell to entertain each other, and those we tell ourselves to get by, and how they are related. Like any good magic trick, it is obvious once it has been explained.