…In the 25 years since I graduated from college, such demands have relentlessly ratcheted up. The quantity and complexity of the mental work expected of successful students and professionals have mounted; we’ve responded by pushing ever harder on that lump of gray matter in our heads.

The result has not been a gratifying bulking up of our neural “muscle.” On the contrary, all the mental effort we’ve mustered over the past year has left many of us feeling depleted and distracted, unequal to the tasks that never stop arriving in our inboxes. When the work we’re putting in doesn’t produce the advertised rewards, we’re inclined to find fault with ourselves. Maybe we’re insufficiently gritty; maybe, we think, we’re just not smart enough. But this interpretation is incorrect. What we’re coming up against are universal limits, constraints on the biological brain that are shared by every human on the planet. Despite the hype, our mental endowment is not boundlessly powerful or endlessly plastic. The brain has firm limits — on its ability to remember, its capacity to pay attention, its facility with abstract and nonintuitive concepts — and the culture we have created for ourselves now regularly exceeds these limits.

The escalating mental demands of the past quarter-century represent the latest stage of a trend that has been picking up speed for more than 100 years. Starting in the early decades of the 20th century, school, work and even the routines of daily life became more cognitively complex: less grounded in the concrete and more bound up in the theoretical and abstract. For a time, humanity was able to with this development, resourcefully finding ways to use the brain better. As their everyday environments grew more intellectually demanding, people responded by upping their cognitive game. Continual engagement with the mental rigors of modern life coincided in many parts of the world with improving nutrition, rising living conditions and reduced exposure to pathogens. These factors produced a century-long climb in average I.Q. scores — a phenomenon known as the Flynn effect, after James Flynn, the political philosopher who identified it.

But this upward trajectory is now leveling off. In recent years, I.Q. scores have stopped rising or have even begun to drop…Some researchers suggest that we have pushed our mental equipment as far as it can go. It may be that “our brains are already working at near-optimal capacity,” write the neuroscientist Peter Reiner and his student Nicholas Fitz in the journal Nature. Efforts to wrest more intelligence from this organ, they add, “bump up against the hard limits of neurobiology.” This collision point — where the urgent imperatives of contemporary life confront the stubbornly intractable limits of the brain — is the place where we live at the moment, and rather unhappily. Our determination to drive the brain ever harder is the source of the agitation we feel as we attempt the impossible each day.

Fortunately, there is an alternative. It entails inducing the brain to play a different role: less workhorse, more orchestra conductor. Instead of doing so much in our heads, we can seek out ways to shift mental work onto the world around us and to supplement our limited neural resources with extraneural ones. These platforms for offloading, these resources for supplementation, are readily available and close at hand…

We, too, extend our minds, but not as well as we could. We do it haphazardly, without much intention or skill — and it’s no wonder this is the case. Our efforts at education and training, as well as management and leadership, are aimed principally at promoting brain-bound thinking. Beginning in elementary school, we are taught to sit still, work quietly, think hard — a model for mental activity that will dominate during the years that follow, through high school and college and into the workplace. The skills we develop and the techniques we are taught are mostly those that involve using our individual, unaided brains: committing information.

The limits of this approach have become painfully evident. The days when we could do it all in our heads are over. Our knowledge is too abundant, our expertise too specialized, our challenges too enormous. The best chance we have to thrive in the extraordinarily complex world we’ve created is to allow that world to assume some of our mental labor. Our brains can’t do it alone.

— Annie Murphy Paul, from “How to Think Outside Your Brain (nytimes.com, June 11, 2021)