In recent years, conversations about AI have focused largely on jobs—how many will disappear, who will be replaced, and what the future of work may look like. Yet the deeper risk posed by AI may be cognitive: a slow erosion of human mental abilities that unfolds quietly.
Earlier this year, I encountered an argument suggesting that AI is becoming a dividing force among humans. Most people, increasingly dependent on intelligent tools, may lose certain cognitive skills, while a smaller minority grows mentally stronger by using AI deliberately. This idea echoes an earlier transformation in human history: the Industrial Revolution.
Machines were invented to free humans from physical labor—from farming and factory work to household chores. I remember my mother spending her single day off each week washing clothes by hand for the entire family. Today, machines handle this task effortlessly. Yet the result was not universal physical well-being. Instead, some used their freed time to stay active and healthy; others became increasingly sedentary. Staying healthy now requires money, time, and willpower—and most people lack at least one of the three or even all of them. When physical effort was no longer necessary, the path of least resistance became inactivity.
AI may be doing something similar to the mind.
Where machines once liberated our bodies, AI liberates our cognition. It allows us to outsource remembering, navigating, calculating, summarizing, even thinking and reasoning, resulting in hollowing our brains. It occurs when the brain learns that certain tasks can be easily handled by external tools. What is no longer required is gradually not used and not preserved.
This phenomenon did not begin with AI. Over decades, television, computers, smartphones, and search engines have each encouraged the brain to outsource certain functions. AI merely deepens and accelerates the process. Navigation offers a clear example. I have noticed the change in myself. Before GPS, I relied on maps. I memorized routes, landmarks, street names and saw the map in my mind. Sometimes I drew my own maps on paper, building a mental image of space. My spatial memory was adequate, even reliable. After years of depending on GPS, much of that ability has faded. I arrive at destinations without knowing how I got there.
Neuroscience reveals the cost of GPS navigation. Studies from University College London show that heavy reliance on GPS navigation is associated with reduced gray matter volume in the hippocampus, a brain region crucial for spatial memory. In contrast, London taxi drivers—who must memorize tens of thousands of streets and landmarks—have hippocampi about 15 percent larger than average. A 2024 study further found that their risk of developing Alzheimer’s disease is roughly one-third that of the general population.
The brain adapts to use and demand. What is often used grows stronger; what is outsourced weakens.
Search engines illustrate a similar shift. A 2011 Harvard study found that once information became easily searchable, people stopped remembering the information itself and instead remembered how to find it. This “Google effect” transformed memory from storage into retrieval. AI takes this one step further. It does not merely locate information; it organizes, interprets, and generates it.
The result is a new cognitive divide. Most people will use AI to reduce effort—outsourcing writing, planning, and thinking whenever possible. A smaller group will use AI differently: as a tool to sharpen reasoning, test ideas, and extend and deepen understanding. As with physical machines, AI amplifies existing habits. It rewards intentional engagement and encourages passive dependence.
AI as a double-edged sword can make cognitive decline comfortable, gradual, and before you realize it. Just as modern appliances did not force anyone to stop moving—but made movement optional—AI does not force us to stop thinking. It simply makes thinking unnecessary.
History offers a clear lesson. Abilities that are no longer required and used won't remain intact by default. Muscles weaken without use. Memory fades without recall. Judgment dulls without practice. Thinking ability is lost without thinking.
The challenge is whether we will continue to exercise our cognitive capacities in a world that no longer demands them, or whether, in trading effort for ease, we will quietly surrender the very abilities that once defined who we are.