Subsumption Architectures, like many of the insects that motivated their design, have a rapid, reflexive response to their environment. Reflexive response is a necessity in a complex, dynamic environment. In the insect world, this policy keeps creatures alive; in robotic domains it allows mechanical creatures to navigate around rooms in real-time while avoiding both walls and people.
Subsumption Architectures gains its reflexive response from the low processing overhead. The pre-wired augmented finite state machines provide fast communication between the sensors and actuators. Furthermore, there is no world model to update or consult, making such systems potentially faster than those with world models.
Reflexive response is obtained at a price, however. The lack of a world-model means that its responses are always and only reflexive. Also, the pre-wired connections require changing the hardware to change an agent's task.
Go to a discussion of this property for multiple architectures.