A Lesson in Intelligence
Moravec's Paradox
The hardest things for AI are easy for toddlers.
The easiest things for AI are hard for PhDs.
In 1988, roboticist Hans Moravec made a puzzling observation: AI could beat chess grandmasters, prove mathematical theorems, and optimize complex logistics. But it couldn't walk across a room, recognize a face, or catch a ball.
Tasks that require years of human education - calculus, chess, logical reasoning - were relatively easy to program. Tasks that every toddler masters - walking, grasping objects, understanding social cues - remained almost impossibly hard.
"It is comparatively easy to make computers exhibit adult level performance on intelligence tests or playing checkers, and difficult or impossible to give them the skills of a one-year-old when it comes to perception and mobility."
- Hans Moravec, 1988
This isn't a quirk of AI design. It's a fundamental insight about what intelligence actually is and how evolution shaped our brains.
The things we think of as "hard" (chess, math) are recent evolutionary hacks.
The things we think of as "easy" (walking, seeing) are ancient and deeply optimized.
What AI Solved When
Explore the timeline of AI achievements. Notice a pattern: abstract reasoning tasks were solved decades before sensorimotor tasks. Chess fell in 1997. Walking is still being worked on.
Abstract Reasoning
10
problems solved
Sensorimotor
5
problems solved
Logic Theorist proved 38 of 52 theorems from Principia Mathematica
BKG 9.8 defeated world champion Luigi Villa
Chinook became unbeatable world champion
Deep Blue defeated world champion Kasparov
Watson defeated all-time champions Jennings and Rutter
AlphaGo defeated world champion Lee Sedol
Libratus defeated top professional players
AlphaFold solved 50-year grand challenge
AlphaGeometry solved olympiad-level geometry
LLMs pass most coding interviews
AlexNet beat humans on ImageNet
Robots can walk, but fail at uneven terrain
Robots struggle to fold clothes, handle soft objects
Reading body language, detecting sarcasm in real-time
Navigating a cluttered kitchen while cooking
Notice: By 2025, AI has mastered chess, Go, poker, and protein folding.Yet robots still struggle to fold laundry.
Drag the slider through time. Watch how abstract tasks fall while physical tasks remain unsolved.
Human Ease vs AI Ease
If human difficulty correlated with AI difficulty, all points would cluster along the diagonal line. Instead, they split into two distinct groups: sensorimotor tasks (easy for humans, hard for AI) and abstract tasks (hard for humans, easy for AI).
Easy human, Hard AI
Hard human, Easy AI
The diagonal line shows expected correlation. Points far from it reveal the paradox.
The paradox becomes clear: tasks in the upper-left (Moravec Zone) are trivially easy for humans but remain grand challenges for AI. Tasks in the lower-right (AI Sweet Spot) require years of human training but were among the first problems AI solved.
500 Million Years of Optimization
The explanation lies in evolution. Sensorimotor skills have been optimized for hundreds of millions of years. Vision evolved 540 million years ago. Locomotion even earlier. Every ancestor that was bad at these tasks was eaten.
Evolution has spent vastly more time optimizing sensorimotor skills than abstract reasoning. The bar widths show relative optimization time (log scale).
Walking: 500 million years of optimization.
Chess: 1,500 years.
Guess which one is harder to engineer.
Abstract reasoning? Chess has existed for 1,500 years. Mathematics as a formal discipline for about 4,000 years. Programming for 75 years. Evolution has barely begun optimizing these skills.
This means sensorimotor tasks aren't actually "easy" - they're heavily optimized. Your brain dedicates massive computational resources to tasks you don't consciously notice. Abstract reasoning is a thin veneer on top of ancient, sophisticated machinery.
Where Your Brain Spends Its Resources
The brain's resource allocation reveals the truth. Most of your neural real estate is dedicated to sensory processing and motor control - not abstract thought. The visual cortex alone uses a third of the cortex. The cerebellum, which coordinates movement, contains half of all neurons in the brain.
Most of your brain is dedicated to sensorimotor processing - the "easy" tasks AI struggles with.
🧠
Sensorimotor Processing
80%
of brain resources
Abstract Reasoning
20%
of brain resources
When you catch a ball, your brain performs real-time calculations of trajectory, adjusting for wind, spin, and your own body position - all in milliseconds, unconsciously. When you solve a math problem, you consciously step through logic using a tiny fraction of your brain.
The Compute Behind "Easy" Tasks
Compare the computational resources required for different tasks. A chess move requires evaluating millions of positions. Walking requires coordinating hundreds of muscles, processing proprioceptive feedback, and making real-time balance adjustments - trillions of operations per step.
Human Brain
Biological neural network
Neurons involved
100M
Time to complete
100ms
AI System
Silicon computation
Operations required
10.0B
Status
Recently solved (2012)
Chess requires ~200M AI operations. Walking requires ~1T per step.
That's 5,000x more computation for something a toddler does without thinking.
The difference is stark: tasks humans find effortless require vastly more computation than tasks humans find challenging. We just don't notice because evolution did the optimization work for us.
Predictions: Confirmed and Pending
Moravec's paradox has proven remarkably predictive. We got language models before robot butlers. AI writes poetry while still struggling to fold towels. Understanding the paradox helps predict what AI breakthroughs will come next - and which will take decades longer than expected.
Language models before robust robot helpers
Predicted: 1988
GPT-4 (2023) vs robot butlers still failing
AI will beat humans at Go before folding laundry
Predicted: 2000s
AlphaGo (2016) succeeded; laundry still unsolved (2025)
Self-driving cars will be "almost there" for decades
Predicted: 1990s
Still Level 2-3 in 2025, edge cases remain
AI writing before AI cooking
Predicted: 2010
ChatGPT writes essays; robot chefs still experimental
Medical diagnosis AI before surgical robot dexterity
Predicted: 2015
AI matches radiologists; surgery robots need human pilots
Moravec's paradox has been remarkably predictive.
Understanding it helps predict which AI breakthroughs will come next.
What Will Be Solved Next?
Use Moravec's paradox to predict how hard any task will be for AI. The key question: does it require manipulating the physical world, or can it be done with pure computation?
Enter a task and use Moravec's paradox to predict how hard it will be for AI.
What This Tells Us About Intelligence
Moravec's paradox isn't just about AI - it reveals something profound about intelligence itself:
We Undervalue Embodied Intelligence
Walking, grasping, and sensing the world requires massive computation that we do not appreciate because it is unconscious. The simple tasks are computationally immense.
Abstract Reasoning is Overrated
Chess and calculus feel hard because we are bad at them - not because they are computationally complex. They are evolutionary afterthoughts built on ancient machinery.
Evolution is the Ultimate Optimizer
500 million years of optimization created solutions more sophisticated than anything we have engineered. We are still reverse-engineering walking.
LLMs Before Robots is Not Surprising
Language is a recent evolutionary development (~200K years). Of course we replicated it before sensorimotor skills. The paradox predicted this.
General AI May Arrive Backwards
We might achieve superhuman abstract reasoning while still struggling with basic physical tasks. AGI might be a disembodied genius.
Human Jobs Will Transform Unexpectedly
Knowledge work (abstract reasoning) is more vulnerable than physical work (sensorimotor). Lawyers before plumbers. Radiologists before nurses.
The Fundamental Insight:
What we call "intelligence" is mostly ancient sensorimotor optimization.
What we call "difficult thinking" is a thin layer of recent evolutionary hacks.
AI solved the thin layer first. The ancient machinery is still being decoded.
The hard problems are easy. The easy problems are hard.
Evolution knew all along.
Want More Explainers Like This?
We build interactive, intuition-first explanations of paradoxes, theorems, and counterintuitive results in AI, statistics, and complexity science.
Reference: Moravec (1988), Brooks (1991)