I've finished Echopraxia. Validating to see Peter Watts noticed the same fridge logic issues with Blindsight vampires that I did:
"Pretty good hack right?" Admiration mingled with fear in Sengupta's voice. "Can you imagine what those fuckers could do if they actually could stand to be in the same room together?"
He shook his head, amazed, trying to take it in. "That's why we made sure they couldn't."
"Made? I thought they were just you know. Really territorial."
"Nobody's that territorial. Someone must've amped their responses to keep them from ganging up on us." Bruks shrugged. "Like the Crucifix Glitch, only - deliberate."
"How do you know that I haven't seen that anywhere."
"Like you said, Rak: it's the only model that fits. How do you think the line could even breed if their default response was to eviscerate each other on sight? Call it the, the Divide and Conquer Glitch." He smiled bitterly. "Oh, we were good." - Echopraxia.
Yeah, not just how they'd even breed if they were like that, but as I kind of touched on previously, "how did any vampires survive their childhoods?" is a huge fridge logic issue with the "vampires kill each other on sight" thing. It makes no sense for a highly intelligent hominid species to kill each other on sight because humans are possibly the most intensely K-strategist animals on the planet and we're like that because we're smart; human babies are extremely vulnerable and dependent because of the big infant head problem and human children need a long period of learning and lots of attention for that extended phenotype of culture to be passed on. Vampires would need a huge exception to the "totally selfish and super-aggressive toward each other" rule just to explain how any vampire survived their childhood, let alone to explain how they managed to develop and maintain any culture (like that click language they supposedly had), and having culture is one of the primary advantages of being smart. And if vampire children were at all like human children I can't even really see it working with just a mother-child bond, for the first years at least there's probably going to need to be at least one other "parent" (father, grandmother, aunt, whatever) to hunt while the mother is stuck with the extremely dependent young child, so that implies that cooperative relationships between adult vampires were possible and common.
Really, the implication is right there even in Blindsight itself, in the part where it speculates that ancient vampires had a language and specifically a language designed to imitate natural sounds so they could talk to each other while sneaking up on prey and you can hear traces of this in modern vampire vocal tics. That implies ancient vampires hunted cooperatively, talked to each other substantially, and had their own culture!
The book suggests this was a genetic tweak (the index mentions alterations to facial recognition mechanisms), but I think it would make a lot of sense if a lot has to do with differences in upbringing. This is the way Echopraxia describes the social environment modern vampires are kept in:
Every vampire ever brought back from the junkyard: scrupulously isolated from their own kind, every aspect of their environment regulated and monitored. Hemmed in by crosses and right angles, mortally dependent on precisely rationed drugs to keep them from seizing at the sight of a windowpane. Creatures that, for all their terrifying strength and intelligence, couldn't even open their eyes on a city street without keeling over.
He shook his head. "They'd never have met. Vampires are hardly ever allowed in the same wing of a building at the same time, let alone the same room. And if they did meet they'd be more likely to tear out each other's throats than draw up escape plans."
So, modern vampires have been raised entirely by people with a radically different neurotype (humans) who have no idea what parenting styles a vampire child would respond well to, in total isolation from any members of their own species. This sounds to me like a recipe for profound social and psychological maladjustment.
Imagine you're a member of a species with low-trust social intuitions and you've been raised by weak, slow, stupid, timid people you intuitively recognize as prey and who are very obviously afraid of you, and then you meet a member of your own kind; a stranger as fast and strong and smart and fierce as you who can credibly look at you and think "I can take them." I bet you'd feel really threatened!
So, yeah, I think plausibly the primary reason ancient vampires weren't so psychotically aggressive toward each other is they had their entire childhoods to get acclimatized to dealing with people with about the same capabilities and mindset as themselves and develop emotional and psychological resources for that.
I like the idea that, like, ancient vampires were profoundly not nice people (for one thing they literally ate people, for another thing given Siri's emotional reaction to Jukka's mannerisms I really doubt most of the ancient vampire DNA in humans got there consensually), but modern vampires are like a Flanderized parody of them with a lot of their worst traits amped up to eleven, because they're kind of like feral children. Like, if an ancient vampire met Jukka or Valerie they'd be like "oh my God, you poor messed-up feral child, what happened to you?"
