He Built an Octopus a Maze to Set It Free
Mark Rober got a pet octopus to find out if they're really as smart as people say — then built her a nine-part underwater maze to prove she was sharp enough to survive being released back into the wild.
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Watch how Sashimi works a problem. She doesn't swim around looking — she walks the space, sending her arms ahead as scouts, tasting and feeling every surface, pushing and pulling to see what gives. When she gets stuck, she'll sometimes just stop and sit, like she's chewing on the data before trying again. And watch for the moment she quits the final maze halfway through and simply cuts to the exit — she's smart enough to solve it and smart enough not to bother.
What makes this so strange is where her intelligence lives. An octopus doesn't think mostly in a central brain the way we do — around two-thirds of its neurons are spread down its arms, which can taste, feel, and act semi-independently. An arm exploring a crevice is partly making its own decisions. It's a completely different blueprint for a mind.
And it really is a different one. The last ancestor we share with an octopus lived over half a billion years ago — a simple worm-like creature with no real brain to speak of. Every animal we usually call clever — dogs, crows, dolphins, us — sits on one branch of that family tree. Octopuses built their intelligence on a separate branch, from scratch. It's the closest thing to encountering an alien mind without leaving the planet.
There's a bittersweet turn, too. Mark set out to test Sashimi, then realized she'd been taken from the ocean and resolved to give her back — the maze was really a way to prove she could still fend for herself. Stay for where she ends up, and for the reason her story was always going to be short.