A mainstream writer once asked me, "Can't you think of any stories to tell about real people?" It's an important question to answer. Just why do SF authors write about aliens? Is it because SF has traditionally dealt with non-humans and, monkey-see monkey-do, we follow the leaders? Are we just pulp fiction freaks who get off on oozing, bug-eyed monsters because they're, well, oozing and bug-eyed? Are we so devoid of insight about the human condition that we need stick tentacles on paper dolls and call them "characters"?
There are lots of good reasons to write alien characters, and they have to do with human beings. Let's take a look at how we hold up aliens as mirrors to our own face.
Social criticism can come across as less preachy and more palatable if the story is about intolerant, bigoted people with funny foreheads instead of folks who look like us. One example is the Star Trek TNG episode "Chain of Command", in which Captain Picard is captured and tortured by a Cardassian. At one point, Picard says to his captor, "Torture has never been a reliable means of extracting information... Whenever I look at you now... I will see a six-year old boy who is powerless to protect himself... In spite of all you have done to me, I find you a pitiable man." Voicing these lines, actor Patrick Stewart was clearly speaking from his personal passion for universal human rights and commitment to Amnesty International. The Cardassian was a stand-in for human torturers; the message was about the reasons for and futility of torture on earth.
Just as aliens can be stand-ins for humans we want to criticize, they can also personify the people we fear. During the Cold War, some SF took a xenophobic turn. Going back to one of the first fantastic novels, Bram Stoker's Dracula is about an entity that is Continental, lives under an absolute monarchist regime, and is not subject to natural law and rational explanation. This entity emasculates nice English men and seduces pure English women. The novel can be read as an exploration of everything upper-class English men most feared in the late 19th century.
Aliens can be mirrors; they can also be like film negatives, giving us a definition of our humanity through omission. In the original Star Trek, the Vulcan Spock's presence provided commentary on the emotional weakness and strength of humans. In TNG, the android Data performs a similar fucntion. C.J. Cherryh's atevi, in her series of novels beginning with Foreigner, lack the human ability to "like," but they possess "manchi" and form associations -- sort of but not exactly like having "loyalty" and "friendship." The translator protagonist struggles to maintain his own humanity while immersed in a nonhuman culture.
Alien characters also shed light on the human condition by interacting with humans. The interaction can be a comedy of errors and misunderstandings, or it can be tragic. Interaction can be cultural, economic, intellectual, erotic, or biological. It can explore the difficulties inherent in diversity as well as the opportunities diversity presents, certainly a theme of omnipresent importance in our world.
So we have lots of good reasons to write about aliens. Now, how do we write them well?
In a bad role-playing adventure, the characters enter a cave complex or abandoned building. There's nothing to eat and nowhere to get bags of gold, or to spend it. Nonetheless, the characters encounter scores of critters carrying treasure.
Don't do this!
Aliens' culture and psychology should arise from their ecology. Why? Because our own frame of reference has been shaped by the conditions of our survival. To write alien characters that effectively mirror, counterpoint, or interact with us, they must be as richly developed as we are. Let's look at some examples of aliens done right.
Returning to C.J. Cherryh's atevi, human Bren Cameron understands them on a gut level when he rides a mechieti in a herd of mechieti and physically feels the animals' fierce desire to cleave to their leader. Atevi differ from humans because of biological hardwiring, a genetic divergence that occurred early in the history of life on the planet. Likewise, Diane Duane's Star Trek novel Spock's World roots Vulcan culture and philosophy in the distant past and the planetary environment.
Now let's think about our own aliens. Are we writing bulge-nosed slimetoads because they're cool, man!, or are we writing with a deeper literary purpose? Here are some questions to ask ourselves:
And voila, or as the Whooziwhats of Wherefore say, zgaphut -- we have strong alien characters who have a reason to be in our story and a life outside it. Oh go ahead, make 'em slimy and green if you want to, as long as it makes sense!