When imagining civilizations on other worlds, we tend to stick to the familiar. Aliens in the popular imagination are not all that different from us — they often have eyes and ears, walk on two feet, and understand the universe in roughly the same way we do.
These unconscious biases mean that the search for alien intelligence has often been little more than a search for ourselves. Yet the universe is far less likely to be populated by pointy-eared Star-Trek-type characters than to contain races of incomprehensible starfish. We tend to forget that we will share more evolutionary history with bananas than with aliens on another planet. Their senses, their social structures, their very sense of self — any of these could be radically different from us.
In recent years, many researchers have tried to unpack the implicit assumptions that have long held sway in the Search for Extraterrestrial Intelligence (SETI). By looking at the diversity of beings here on Earth, scientists are starting to realize the difficulties that could be inherent in communicating with those on other planets.
“I think we essentially limit ourselves when we decide that something is true without testing that it has to be true,” said linguist Sheri Wells-Jensen of Bowling Green State University in Ohio. “We know what’s common and useful here, but we haven’t been in all these situations where what we assume doesn’t apply. So we need to systematically step through all our assumptions, and go, ‘Yeah, that’s a really interesting idea and I’ve always thought that it’s true, but what if it isn’t?’”
This May, Wells-Jensen spoke at a Messaging Extraterrestrial Intelligence (METI) conference at the Arecibo Telescope in Puerto Rico about one major presumption she’s noticed in discussions of alien intelligence — that they will be sighted. Eyes have been useful for most species on Earth. But astronomers have discovered a rich diversity of exoplanets, suggestive of the wide range of environments extraterrestrial creatures could find themselves in. They might live on a hazy world with little light, or underground like star-nosed moles, or deep in caves as many fish and insects do.
Being blind herself, Well-Jensen is aware that most people tend to overestimate the amount and quality of information gathered through vision alone. Sight may be advantageous, but it’s not the only way to go. She imagined an unsighted species she called the “Krikkits” — a nod to both blind cave-dwelling cricket species on Earth and a well-meaning but unfortunately genocidal race in Douglas Adams’ Hitchhikers Guide to the Galaxy series — and asked how their scientific and technological history might unfold.
For Krikkiters, touch and hearing would probably be the dominant senses. One possible early invention for them could be a stick or other tool for probing their immediate environment, and they would likely be able to distinguish different plants and rocks through feel alone. They might naturally possess echolocation like bats, or they might learn to emit clicks like blind humans and listen for the reflection. Which means that early on, they would know a great deal about the nature of sound — that it’s a vibration, that it travels through air, that it moves at different speeds in different media. Perhaps their geometry would be devoted to figuring out the angles that sounds travel in after bouncing off objects.
As they progressed, the Krikkiters could learn about chemistry and the laws of motion and might eventually gain enough information to construct radio telescopes. Wells- Jensen thinks this could lead to monumental discoveries. A blind species might not know about the existence of a moon or moons around their planet until they were able to point telescopes upward and bounce radio waves off them.
Now before you start feeling so smug about our ability to know about something as basic as the moon, remember electricity. It was only formally discovered about 150 years ago, and it took some of the smartest minds of the 19th century to deduce its fundamental laws. But had we humans been able to talk to sharks or another electroreceptive animal, they could have told us “Oh yeah, of course we know about electricity. You guys are just catching up now?”
What this points to is the fact that there is no natural order to discovering particular aspects of the universe. Just because humans knew about the moon and stars early on doesn’t mean we can assume that other intelligent species will. This wouldn’t necessarily be to their disadvantage. “There could be things they know that we would have no idea about, and we would think are crazy,” said Wells-Jensen.
Another set of hidden assumptions about intelligence becomes obvious when examining cephalopods — the class of mollusks that includes squid, octopuses, and cuttlefish. Looking at the differences between them and us has been the job of behavioral neuroscience graduate student Dominic Sivitilli and his advisor David Gire, both of the University of Washington, who also spoke at the METI conference in Arecibo.
Cephalopods are highly intelligent. They are curious and love to investigate new things. They engage in play, and experiments have shown their ability to recognize human faces and learn spatial tasks. Plenty of stories attest to octopuses’ Houdini-like skills at sneaking out of man-made enclosures. Which is especially impressive considering that cephalopods are invertebrates, putting them in the same taxonomic company as worms and flies.
Two-thirds of an octopus’ nervous systems is in its arms, each of which is covered in hundreds of extremely sensitive suckers that can pick up chemical information about the environment. Octopuses can detect dilute chemicals 100 times better than humans and can be taught to distinguish objects by chemical composition alone. A great deal of this information processing happens independent of the brain. “The arms are more conscious collectively than the central nervous system,” said Sivitilli. “They’ve outsourced much of their cognition to their peripheral nervous system.”
In humans and other mammals, specific regions of the brain control specific body parts. But the brain and arms of an octopus are in constant communication and collectively decide on which actions to take. For instance, the brain can send a signal for the arms to bend toward the mouth, but only those arms currently clutching food will actually do so. This type of autonomous processing means that an octopus essentially has eight smaller brains working and coordinating together.
“It puts into question ideas of mind and ego and consciousness,” said Sivitilli. “Considering how much of its mind is in its arms, does it need something like the ego? Those are terms we like to throw around a lot when thinking about intelligence.” Perhaps an octopus-like alien would refer to itself not as an ‘I’ but as a ‘We.’
Some researchers have hypothesized that intelligence evolved as a way for individuals to keep track of social interactions within a group. And while certain cephalopods, such as squid, live collective lives, octopuses are solitary creatures. Despite spending almost no time in the presence of other individuals like themselves, they manage to be extremely smart. This stands in contrast to other intelligent animals such as humans, primates, elephants, ravens and crows, and dolphins and whales. “They’re really the only case of an asocial intelligence that we know of,” said Sivitilli.
Octopuses are known to use tools, such as coconut husks for protective shells. Perhaps, suggest Sivitilli and Gire, an octopus-like alien race could reach a certain level of technology while remaining asocial, and then “invent” sociality as a useful tool. This would be a rather different trajectory from what we normally presume.
Given all these constraints, is it even possible to go about messaging these strange aliens? Sivitilli and Gire think so. They offer one common trait we might share with extraterrestrials — the desire to gather information. An intelligent creature would presumably seek out new knowledge. Therefore, any interstellar message we construct should contain something that they might not know about the universe. A highly- detailed star map of our local environment, with information about planets and other small bodies they probably can’t detect, might do the trick.
This type of message is more like a “public service announcement” than any kind of two-way communication, said Gire, but it could at least be an attractive starting point.
By sending out radio messages, we are narrowing ourselves down to only extraterrestrials that have invented radio telescopes. But no technology is objective, and the technological history of alien civilizations might look very different than ours. It’s therefore difficult to predict exactly what kinds of scientific information an alien species would be seeking out.
“Maybe we have to tighten down our presuppositions about what will be common knowledge,” said Wells-Jensen. “Especially if I can build you a radio telescope without knowing there are stars.”
Despite the difficulties, Wells-Jensen remains optimistic that deeper examination of these issues will lead to better message construction. “We go with what we think we know, we go with our assumptions, and then we refine them later,” she said. “But I think we are creatures that do things, and so we’re going to do this.”
This story was originally published on the defunct website now.space on 7/29/2016