The Genius Spiders Changing How We Think About Brains

Picture a hunter stalking its prey. Its keen eyes constantly take in its surroundings  and plot the best course to its unwitting lunch.

It plans its attack based on the victim’s  attributes and immediate surroundings,   and uses these to pin its victim down.

It patiently executes every move with not  merely primal instinct, but wily calculation.

It's done this before and has  honed its approach with experience.

At just the right moment, it pounces  with a big leap, taking down its meal.

This sounds like a scene from Tom and  Jerry, or like a human hunter in the woods.

But what I’m describing is not a cat, or  even a mammal, or a bird or a reptile.

It’s not even a vertebrate. It’s a spider.

And not just any spider, but a genus  of jumping spider known as Portia.

These spiders are so smart that they have  upended how scientists look at cognition,   especially in invertebrates.

They’re forcing us to totally  rethink how we think about thinking.

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So these spiders are among  certain invertebrate species,   including octopuses and bees,   changing how we see cognition Before researchers started taking a closer look  at these animals, they assumed that an animal’s   cognitive abilities should be roughly proportional  to morphological complexity and brain size.

Researchers believed that something with  an exoskeleton and a brain smaller than   a pinhead shouldn’t be capable of the  things Portia can very obviously do.

We’re talking about things like  learning through trial and error,   anticipating future events, intentional deception,   and even REM-like sleep behavior, complete  with eye movements and twitching limbs.

The processing power required  to run the animal’s cognition   should not fit into such itty-bitty hardware.

And yet, the spiders think in uncanny ways,  like learning through trial and error.