Intelligence is a "sentient" trait.
Artificial Intelligence *mimics* that trait. So in a sense, even simple, scripted, package managed behavior is a form of artificial intelligence. Citizens typically get the least amount of attention. Which is typical, but VERY ignored in this game. Skyrim and Fallout 4 were very much the same in that regard. Until a few modders tweaked the citizen A.I. to make them more *lively*.
There are a number of different A.I. packages running among the game's various npcs. All very basic, and essentially doing their own thing, oblivious to anything other npcs around them are doing. I'd expect a number of modders to eventually rework the A.I. packaging of most of the game's npcs once the game is stabilized and debugged.
Here's a simple tweak I found on Nexus last night that makes the npcs you see walking the streets seem to move around more *naturally*, and a lot less rigidly. Basic yes. But a decent enough example of how much modding can improve how a game looks and feels. A full-blown A.I. overhaul mod would get straight into the package script to modify the actual behavior, and how npcs respond to events involving the player, AND the other npcs around them.