I have an essay in Aeon magazine on the possibility that machines might become conscious without our realizing it and possible ways to test for that. A huge variety of physiological and behavioral tests of consciousness might be adapted to machines, and Spanish AI researcher Raúl Arrabales Moreno and his colleagues have systematized them as a 12-level scale of consciousness. They have an online calculator that you can use to rank putative conscious beings.

	Level	Explanation	Animal Example	Human Age Equivalent	Machine Example
–1	Disembodied	Blends into environment	Molecule
0	Isolated	Has a body, but no functions	Inert chromosome		Stuffed animal
1	Decontrolled	Has sensors and actuators, but is inactive	Corpse		Powered-down computer
2	Reactive	Has fixed responses	Virus	Embryo to 1 month	ELIZA
3	Adaptive	Learns new reactions	Earthworm	1–4 months	Smart thermostat
4	Attentional	Focuses selectively, learns by trial-and-error, and forms positive and negative associations (primitive emotions)	Fish	4–8 months	CRONOS robot
5	Executive	Selects goals, acts to achieve them, and assesses its own condition	Octupus	8–12 months	Cog
6	Emotional	Has a range of emotions, body schema, and minimal theory of mind	Monkey	12–18 months	Haikonen architecture (partly implemented by XCR-1 robot)
7	Self-Conscious	Knows that it knows (higher-order thought) and passes the mirror test	Magpie	18–24 months	Nexus-6 (Do Androids Dream of Electric Sheep?)
8	Empathic	Conceives of others as selves and adjusts how it presents itself	Chimpanzee	2–7 years	HAL 9000 (2001)
9	Social	Has full theory of mind, talks, and can lie	Human	7–11 years	Ava (Ex Machina)
10	Human	Passes the Turing Test and creates cumulative culture	Human	12+ years	Six (Battlestar Galactica)
11	Super-Conscious	Coordinates multiple streams of consciousness	Bene Gesserit (Dune)	augmented	Samantha (Her)