He offers an evolutionary hypothesis:
Barash reasons that a less intelligent creature would need more pain than a more intelligent one, in order to teach it to avoid risk and harm:
The dummies, accordingly, would benefit more than the smarty-pants from an especially potent stimulus, a blast of something deeply unpleasant—call it “pain”—more likely to evoke whatever passes for memory and learning in their admittedly dim minds. If so, then they would benefit from a particularly loud alarm bell: More pain rather than less.DAVID P. BARASH, “EVEN WORMS FEEL PAIN” AT NAUTILUS (MARCH 2, 2022)
Thus he concludes, “Pain would have been among the most fundamental traits to have emerged.”
Given the adaptive value of pain, that sensation would not only be conserved over evolutionary time, but ancestral, among the earliest and most fundamental traits to have emerged. This makes it, well, pretty much insufferable to deny other animals the experience of pain that we know all too well.DAVID P. BARASH, “EVEN WORMS FEEL PAIN” AT NAUTILUS (MARCH 2, 2022)
Wait. Barash’s hypothesis overlooks the fact that suffering is more than an alarm system. An alarm could be going off in an empty building.
If a fire alarm went off in an empty building, a built-in fire safety protocol might seal all the windows, turn off some systems, and send a message to the firehall, copying the maintenance crew’s mailbox, without anyone experiencing anything. Life forms are fully capable of much more complex responses than these, even without any apparent self-awareness. Tests for the self-awareness that would cause them suffering cannot depend only on identifying a response to pain.
To “feel” pain, a life form must have a unified self, that is, be a subject of experiences. We all know that a dog experiences pain or rejection as happening to him as the subject of the experience. But does an earthworm experience pain that way?
Essentially, experiencing pain (sentience) can mean either of two things: the ability to react to pain or the perception of the pain as happening to one’s unified self. Or both.
We risk trivializing the question of suffering — and impeding humane reforms — if we cast the net too widely.News, “Evolutionary psychologist argues that worms feel pain. But how?” at Mind Matters News (April 5, 2022)
Takehome: If some invertebrates show much more self-awareness than expected, it hardly follows that all do. We risk impeding humane reforms if we cast the net too widely.
You may also wish to read:
Can crabs think? Can lobsters feel? What we know now. In Switzerland, it is now illegal to boil a lobster alive. Are the Swiss right? Is it cruel? How does a self that feels pain come to exist? And how do we distinguish information use — computer style — from self-awareness?