Sometimes, I think, science fiction authors have a better idea of potential alien complexity than do biologists. Here’s an essay by Tim Pratt on alien worldbuilding that does a good job of addressing a common problem.
I knew my series needed aliens, just like it needed mysterious ancient technological artifacts, space pirates, snarky computers, and cool spaceships. Turning to the task of creating aliens right after I’d put together my (mostly) human crew made me hyperaware of the issue of culture. One thing that bothers me in some science fiction (more often cinematic and televisual than written, but often there, too) is alien monocultures. Unless you’re talking about the Borg or Cybermen or other sorts of hive-minds, it never made sense to me to have an entire species of aliens with a single culture. How many thousands of cultures are there on Earth, after all, and how many subcultures within those cultures? From differences in music, religion, recreation, art, literature, food, philosophy, sexual preferences—cultures and subcultures get so wonderfully and weirdly granular. And yet, so often when our fictional humans encounter aliens, they discover the whole species consists of noble warriors or aloof philosophers or sadistic experimenters or ruthless capitalists. Where are the pacifist Klingons who run sustainable free-range krada ranches? Where are the Wookies who like to shave their entire bodies and refuse to celebrate Life Day because it’s gone too corporate? The Volus philanthropists? The punk rock Vulcans? Sure, sometimes there’s a plot point involving some rogue weirdo outlier, but in any alien species there should plausibly be whole communities, whole cities, whole religions or sects or affinity groups, who march to the beat of a different Kintarrian Death Drum.
Yeah! Diversity is important. I think I’m going to have to grab a copy of his series.