I just spent all morning watching episodes of Cracked's series Today's Topic, because having spent the last several days marathoning episodes of Hypnotizd's modded Minecraft Let's Play I'm a little burnt out on long-form YouTube. And anyway, I just got to the one about Firefly, "Why the 'Firefly' Crew Were the Bad Guys," and it reminded me of a thought I've had that I can't remember having actually written down. I'm assuming since Serenity came out 10 years ago, and River's powers are addressed in the first, like, 10 minutes of the movie, it's not a spoiler that she's psychic, even though it's not addressed outright in the TV show until the last few episodes. Still, if you haven't watched Firefly yet, and you're avoiding spoilers, I'm going to address specific details below so skip today and come back.
Firefly is pretty hard science fiction. It all takes place in one solar system, so while the mechanics of space flight are never made explicit, it's possible that it's not faster-than-light. Medical technology is extraordinarily advanced, but still requires professionals and goes wrong, especially in low-resource environments like the outer planets. There are no laser guns, tractor beams or teleporters.
The only significant exception to that trend is River's psychic powers. The show lampshades that at the end of the series --
Wash: Psychic, though? That sounds like something out of science fiction. Zoe: We live on a spaceship, dear.
-- but her abilities are otherwise straightforward. She can read people's minds, which seems like a complete departure from any known human ability. Except, like, empathy.
River was presented as an extraordinary person, a prodigy even compared to her brother, who was also absurdly smart. And we learn in the series that what the Alliance did to her wasn't adding anything to her brain, it was removing. They stripped away her ability to suppress emotional experience. Possibly, they removed her ability to hold anything back out of her consciousness.
I think all of River's abilities can be reasonably attributed to taking one of the most perceptive people in a sample size of like a hundred billion, and removing their ability to stop paying attention. After a couple minutes in a room with someone she can perfectly match their mannerisms; by watching their expressions she can fluidly intuit their approximate motives, interests, weaknesses and fears; her fighting ability is her pre-existing talent for dance plus an ability to read her opponent as well as an expert martial artist (plus probably some Alliance training); I'd say "And so on," but that pretty much covers everything she accomplished. Even the stuff she appears to have gleaned from the minds of Alliance officials could just be, like, the ability to successfully approximate the content of a conversation through lip reading and expressions. If there were any hint at all in the environment of the landing site on Miranda, she could put together a mental picture of exactly what had happened. She wouldn't be able to help it. She'd be like an overclocked Sherlock Holmes.
So... yeah. No psychic powers in Firefly. I think this is really fun to think about, because it's a serious development of science fiction ideas based on a cutting-edge understanding of the mind, rather than a half-century-old one.