Spider Smarts: Data Show Their Minds Extend Into Their Webs

“Webs are like instruments that spiders carefully ‘tune’ according to their experiences.” —David Robson

A recent essay in New Scientist by David Robson called, "Spiders think with their webs, challenging our ideas of intelligence," is a fascinating read. Each time I read it I learn more and more about these amazing beings, as I also go to some of the original research papers.

I want to provide a few snippets from Mr. Robson's incredibly thought-provoking piece to generate more interest in these nonhumans who frequently are written off as dumb automatons. Clearly, they're not, and there's a lot more in "Spiders think with their webs..." than I recount here. It's not yet available online for free, however, I strongly encourage readers who want to learn more about current research on the complex and unanticipated cognitive lives of a wide variety of spiders to purchase it.

Alien intelligence: The inner lives of spiders

In the written version of Mr. Robson's essay we read, "Arachnid intelligence is challenging our ideas about brains and consciousness–and their minds may even stretch into their webs." He begins, "There is an alien intelligence living among us. These creatures possess an extraordinary kind of consciousness, including minds that extend beyond their bodies. Yet, thanks to our ignorance and arrogance, our immediate impulse is to kill them."

Jumping spider.

Source: ROverhate, Pixabay free download

Here are some facts about the inner lives of spiders, eight-legged intellects with minute brains:

• Their cognitive abilities "rival those of mammals and birds, including foresight and planning, complex learning and even the capacity to be surprised."
• Their highly tailored webs should be considered part of their minds.
• About one-third of all spiders make orb webs that "hold more secrets than Charlotte’s Web, because each is a record of the decisions taken during its construction."
• Spiders' ability to make intricate webs indicate they form mental representations of the space in which they want to construct them. Mr. Robson writes, "They tweak the tension of silk strands in the areas most likely to trap unsuspecting insects, based on their previous catches. Increased tension boosts the transmission of vibrations from a struggling insect, allowing the waiting spider to respond more quickly. They also alter the dimensions of the web according to the size of prey found locally."
• About jumping spiders of the genus Portia we're told, "'They hunt like tiny cats,' says Fiona Cross at the University of Canterbury, New Zealand. This often involves premeditation and careful route planning, as her research reveals." We also learn they use premeditation to ambush dangerous prey.
• Concerning the evolution of spiders' advanced cognition, we are told, "...a spider’s past experiences can determine the structure of its web, which, in turn, alters what it senses in its environment, directly influencing its future decisions. As a result, part of a spider’s memory and decision-making is outsourced beyond its body. Spiders have extra selective pressure for evolving extended cognition because of their relatively tiny brains and their high cognitive requirements as generalist predators.”

Mr. Robson concludes, "...a greater appreciation of spider smarts might give us all pause for thought the next time we are confronted with eight-legged squatters hiding in our hallways. Written on their silken webs, we may one day find clues to the origins of thought itself."

If I had read the last paragraph of his essay first, I would have thought it was somewhat overblown. However, after reading his piece and some of the original research papers, I realize it's not.

Stay tuned for further discussion of the cognitive lives of spiders. I hope you are as intrigued as I am by the detailed research on their advanced and unexpected cognitive capacities. I also hope this brief review will motivate you to learn more about these brainy, but tiny-brained, invertebrates. I can't wait to learn more about them and other supposedly "not-so-smart" animals.¹