Does anybody know if the AI is programmed to research techs in a certain order?

In most of my games most civs seem to research stuff in the same order. Mansa will always go down the physics/electricity/radio/mass media line, usually trading for rifles and assembly later, if ever.

Churchill will make a beeline for rifles much, much earlier than most other civs.

Elizabeth will always beeline for liberalism.

Victoria seems to always get Economics if i don't immediately go for it after liberalism.

So obviously some civs are programmed to spam settlers, others are set to build wonders, others to build units. Are the techs they chose also preset, or is it just a coincidence and the techs they choose are a result of their AI personality towards other things or the circumstances. Will Mansa prioritize rifles and infantry if he's been under attack the whole game, for example?

I don't think they have a fixed tech beeline order, but they do have certain tendancies. There are six "flavours": growth, gold, science, military, culture and religion. Each AI leader is programmed to focus on one or two of those flavours. I'm not quite sure exactly how they fit in with technologies, but I think each tech has a particular value for each flavour (or maybe for a couple of flavours). Ever noticed how the computer recommends one or two techs with you when you need to decide what to research? It uses the flavours as justification - eg. "research compass (growth)".

This is what influences the order in which the AI researchs techs. For example, Isabella puts a lot of emphasis on techs with a religious flavour, which is why she's usually first to research meditation or polytheism. Her second flavour is growth, so she'll also head down the naval techpath relatively quickly (in theory).