Should We Fear Aliens?

Karl Gantner, whose story “Killing a Tiger” can be found in our current issue, takes on a topic that has oft fascinated SF writers and readers alike….

by Karl Gantner

Should we fear aliens? On one hand, it seems absurd that intelligent extraterrestrial life would come all this way to harm us when there is such abundance elsewhere in the galaxy. Earth has no unique minerals that couldn’t more easily be mined from asteroids. Watts generated from our Sun are no different than from any of the millions of other stars in the galaxy. The fear we feel imagining some alien invasion (à la War of the Worlds) must be nothing more than an evolutionary leftover that has us imagining stalking tigers behind every rustling bush.

But what if that fear is not vestigial? What if it’s telling us something important about our universe and survival? Exploring this idea is at the center of KILLING A TIGER—my new short story in Analog’s July/August issue.

KILLING A TIGER is centered around a decision that the protagonist, Rodion, must make when his spacecraft observes an alien probe departing the Solar System. Does he let it go, and reveal humanity’s existence to some unseen life form, or does he shoot it down, and keep our system hidden from any covetous alien eyes? You’ll have to read and let me know what you think he ends up choosing (tweet @karlgantner). More on Rodion later.

Inspiration for this story came from an idea: if evolution is true here on Earth, then it is true throughout the universe, and the process of natural selection that has produced humans—with all our flaws and neuroses—will be the same one that produces any intelligent extraterrestrial life we may encounter.

This should concern us.

We need only look at life on Earth to see that the traits we hope ET to have (kindness, agreeableness, empathy) are exceptionally rare, and when they do exist, only extend to kin (of which aliens most certainly won’t confuse us for). We should recognize that any intelligent alien life we may contact is unlikely to be the scientific humanitarians we hope them to be, and more likely will be tough survivalists with a deep innate drive to aggressively spread.

If aliens can navigate the stars to come to visit us, it’s natural to expect them to be highly intelligent, rational beings; however, rationality is not a requirement to spread. By biomass, arthropods (cicadas, scorpions, butterflies, crabs, centipedes) represent the most successful animal life on Earth, with more than 17-times greater biomass than humans. No arthropod has kindness, agreeableness, empathy, or an ability to apply abstract logic to draw conclusions about the outside world. Arthropods operate according to survival heuristics programmed into their comparatively simple brains to survive long enough till they can reproduce above the replacement level. Evolution has favored rationality in only 0.01% of all life by biomass. Though it seems unlikely that any life without rationality would be able to leave its homeworld and travel across the stars, that may be our bias talking. Remember, we don’t have any evidence yet that rationality is capable of traveling the stars either. Those noble traits we as humans uphold are very uncommon in the grand scheme of life.

But even if alien life is rational, can we expect them to treat us with kindness and empathy? Evidence is to the contrary. When these behaviors do evolve in nature, they evolve in animals that rely on a social group to survive and almost always are directed towards kin. There is a depressingly long history of humans showing compassion to their kin-group while treating other humans with distain and hatred. (For evidence, open the nearest history book and flip to any page.) Kindness and empathy exist in nature, but there is no evolutionary pressure for it to be extended beyond the social group, much less to members of different species. There are no natural forces of selection that motivate intelligent alien life to show any compassion or empathy towards us.

Traits that would turn extraterrestrial life into scientists and humanitarians, are not likely to be the dominant ones that we encounter in life outside our planet. We should expect to find aliens that are survivors and spreaders, who can withstand hardship and multiply themselves aggressively in a wide variety of environments.

So what should we do about it? First, we should be listening for signs of intelligent life to understand how many there are out there, but by no means should we be advertising our position. Secondly, we should not be under any illusions about how we should expect alien life to behave. Don’t expect aliens to be reasonable scholars eager to learn about new life for the intellectual pleasure of it. Expect nervous xenophobes, curious but skittish scavengers, uninterested leviathans on million-year migrations, or hungry tigers pushed from rich hunting grounds into unexplored space.

But I could be wrong. What makes this debate difficult is that we haven’t observed any form of alien life—intelligent or not. Maybe evolution doesn’t work the same on other planets? Maybe there’s a deeper mechanism at play we can’t yet see? Which brings us back to Rodion, the protagonist in KILLING A TIGER [on sale now]. What Rodion chooses depends not so much on these arguments, but on what past events speak to him in that moment where he must decide to kill or free the alien probe. If you were in his place, with just a moment to react, what part of your own history would influence your decision?

As authors, our job is to understand what goes on in the mind during these critical decisions. These moments define our characters, and give us insight into our own lives. None of us may live long enough to witness contact with intelligent extraterrestrial life—if it ever happens—but through engaging with fictional characters as they struggle through difficult choices, we can better appreciate the messy human calculus that influences our own lives.

—Karl, @karlgantner


  1. They might come here to exterminate us out of compassion for us , or the way some people would eliminate a particularly ugly and dangerous insect colony


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