I used SETI as an analogy a couple of days ago, but there really are people looking for signs of alien life in the universe. Jim Cambias discusses the three main motivations he sees in doing so: Conviction, Greed, and Fear.

Charles Daney says:

But it seems to me that there's a simple and obvious reason -- the same as what motivates most pure science -- curiosity. And maybe a less obvious reason, too: humans seem to be encumbered with an inferiority complex (perhaps well-deserved) that goads them to seek sentient beings "higher" or more advanced than humans. Same thing that explains religion and Star Trek fandom too. Y'know, you read the daily news and think surely there has to be something out there smarter than humans....

I think he's right about the first one. It's probably plain old curiosity.

But the second reason? I don't know what science fiction he's reading or watching, but damn near all of it imply the inherent superiority of humans, even over supposedly "advanced" aliens they run into.

Take his example of Star Trek. In the old one, Kirk was always teaching aliens a lesson, either with fisticuffs, a phaser, or a few stern words at the end of the episode.

In the new Star Trek, Q was a good example of a supposedly superior species. But he was fascinated by humans. Okay. And Picard was always showing himself to be wiser than this multi-dimensional, semi-omniscient being. Data's never-ending quest to not only understand being human, but to become human was another conceit that revealed the writers' blatant anthrocentrism. Why didn't most of the crew aspire to be more like him than the other way around?

You find these ideas throughout most science fiction, though. It's not just Star Trek. If anything, it's a superiority complex, not the other way around.