To be fair, the AI in STALKER (A-Life) was dialled down significantly prior to release as although it performed great, it made for a poor narrative experience as you could never really ensure it wouldn't break the game continuity in some way.
There are mods out there now that allow you to enable the full A-Life simulation and honestly it is very impressive even to this day.
There are mods out there now that allow you to enable the full A-Life simulation and honestly it is very impressive even to this day.