Creating aliens is fun and all, but why do we do it? Mostly, it’s because those aliens are going to have some role in our stories. And what kind of organism plays the biggest role? For most, that would be the intelligent kind.
Sentient aliens are the ultimate goal, thanks to a lifetime of science fiction. Yes, the discovery tomorrow of indisputably alien bacteria on Mars would change the entire world, but we’re all waiting for the Vulcans, the Mandalorians, the asari, or whatever our favorite almost-human race might be.
Mind over matter
It’s hard to say how plausible sentience is. We’ve only got one example of a fully intelligent species: us. Quite a few animals, however, show sophisticated behavior, including dolphins, chimps, octopuses, and so on. Some are so intelligent (relative to the “average” member of the animal kingdom) that authors will draw a line between sentience (in the sense of feeling and experiencing sensation) and sapience (the higher intelligence that humans alone possess). For aliens, where even defining intelligence might be nearly impossible at the start, we’ll keep the two concepts merged.
A sentient alien species remains a member of its home biosphere. We’ll always be evolved from our primate ancestors, no matter what the future holds. It’ll be the same for them. Their species will have its own evolutionary history, with all that entails. (Hint: I’ve spent quite a few posts rambling on about exactly that.) The outcome, however, seems the same: an intelligent, tool-using, society-forming, environment-altering race.
We don’t know much about how higher sentience comes about. We don’t even know what it means to have consciousness! Let’s ignore that minor quibble, though, and toss out some ideas. Clearly, intelligence requires a brain. Even plants have defensive mechanisms activated when they feel pain, but it takes true brainpower to understand what happens when inflicting pain upon another. Sentience, in this case, can be equated with the powers of reasoning, or an ability to follow logical deduction. (Although that opens the door to claiming that half of humanity is not sentient. Reading some Internet comments, I’m not sure I would disagree.)
Other factors go into making an intelligent alien race, too. Fortunately, most of them default to being slightly altered expressions of human nature. Sentient aliens usually speak, for example, except in some of the more “out there” fiction. Even in works like Solaris, however, they still communicate, though maybe not always through direct speech. Now, we know language can evolve—I’m writing in one of them, aren’t I?—but it was long thought that humans were the unique bearers of the trait. Sure, we had things like birdsong and mimicry, but we’re the only ones who actually talk, right? Attempts at teaching language to “lesser” animals have varied in their efficacy, but recent research points to dolphins having at least a rudimentary capacity for speech. That’s good news for aliens, as it’s a step towards disproving the notion that language is distinctly human.
What else do humans do? They form societies. Other animals do, too, from schools of fish to beehives and anthills, but we’ve taken it to new extremes. Sentient aliens probably would do the same. They may not follow our exact trajectory, from primitive scavengers to hunter-gatherers to agrarian city-states to empires and republics, but they would create their own societies, their own cultures. The shapes these would take depend heavily on the species’ “upbringing”. We’re naturally sociable. Our closest animal kin show highly developed social behaviors—Jane Goodall, among others, has made a living off researching exactly that. An alien race, on the other hand, might develop from something else; imagine, for instance, what a society derived from carnivorous, multiple-mating, jungle-dwelling ancestors would look like.
Likewise, the technological advancement won’t be the same for aliens as it was for us. Some of that could be due to basic science. An aquatic species is going to have an awful time crafting metal tools. Beings living on a higher-gravity world, apart from being generally shorter and stouter, might take much longer to reach space, simply because of the higher escape velocity. A species whose planet never experienced an equivalent to the Carboniferous period could be forced far sooner into developing “green” energy.
Differences in advancement can also stem from psychological factors. Humans are altruistic, but not to a fault. We’re basically in the middle of a spectrum. Another race might be more suited to self-sacrifice (and thus potentially more amenable to socialist or communist forms of organization) or far less (therefore more likely to engage in cutthroat capitalism). Racial, sexual, and other distinctions may play a larger or smaller role in their development, and they can also drive an interest in genetics and similar fields.
Even their history has an effect on their general level of technology. How much different, for instance, would our world be if a few centuries of general stagnation in Europe—the Dark Ages—never occurred? What would the effects of “early” gunpowder be? Aliens can be a great place to practice your what-ifs.
The garden of your mind
We are sentient. We are sapient. No matter how you define the terms, no other species on Earth can fit both of them at the same time. That’s what makes us unique. It’s what makes us human.
An alien species might feel the same way. Intelligence looks exceedingly rare, so it’s stretching the bounds of plausibility that a planet could hold two advanced lifeforms at the same time. On the other hand, science fiction is often about looking at just those situations that sit beyond what we know to be possible.
One or many, though, aliens will always be alien to us. They won’t think just like us, any more than they’ll look just like us. Their minds, their desires and cares and instincts and feelings, will be different. For some authors, that’s a chance to explore the human condition. By making aliens reflections of some part of ourselves, they can use them to make a point about us. Avatar, for example, puts its aliens, the Na’vi, in essentially the same role as the “noble savages” of so many old tales. Star Trek has Klingons to explore a warrior culture, Vulcans for cold, unassailable logic, and hundreds of others used for one-off morality plays.
Others use aliens to give a sense of otherworldliness, or to show how small, unimportant, or deluded we humans can be. Aliens might be a billion years older than us, these stories state. They’d be to us what we are to trilobites or coelacanths…or the dinosaurs. Or if you want to take the view of Clarke and others, a sufficiently advanced alien would seem magical, if not divine.
Whatever your sentient aliens do, whatever purpose they serve, they’ll have thoughts. What will they think about?