Behold Stentor roeseli, a tiny trumpet-shaped unicelluar organism:
Turns out our little friend is not a preprogrammed automaton but an unpredictable creature of “unexpected depths”, a complex and strategic decision-maker capable of “changing its mind” in response to failure. For example, Stentor roeseli can “dodge, duck or flee” to avoid a threat, alternating these evasive maneuvers in a seemingly random manner until the threat is gone. Here’s a nice illustration by American zoologist Herbert Spencer Jennings:
Some philosophers consider unpredictability central to the notion of free will. For example, Daniel Dennett says free will exists because individuals have the ability to act differently from what anyone expects. And JT Ismael writes:
“One of the things that we know about persons, for example, is that they are wild cards. How they react to a given piece of information depends on so many internal variables that there is no effective way of predicting it with either precision or certainty.” (Ismael, 2016 How Physics Makes Us Free)
But Stentor roeseli are unpredictable wild cards too! Does that mean they have free will? If not, why not? If not Stentor roeseli, how about mice and rats? To quote liberally from myself:
“Regret is the recognition that one made a mistake and that an alternative action was possible. …And mice feel it! This from "Mice learn to avoid regret", whose authors [Sweis, Thomas and Redish] found evidence that mice exhibit ‘regret-like behaviors following change-of-mind decisions’ … [and per Judea Pearl] with regret comes responsibility and blame. ” Mice Feel the Pang of Regret/Exploring the Problem Space. August 7, 2018
“Did you know that rats navigate “into the future by considering future possibilities and electing action in light of the benefits and risks they promise”? (Seligman et al, 2013)…In other words, rats make choices based on what they want and what they consider possible. They imagine the future, weigh the relative merit of different actions, seek additional information if needed, choose what to do, and then act. They are agents with desires and goals. A lot like us.” Do Rats Have Free Will?/Exploring the Problem Space. June 29, 2018
Personally, I think “free will” is an outdated and useless concept. The issue for me is whether people are responsible for their actions. But that’s a whole other can of worms.
References:
A single-celled protist reacts to threats in surprisingly complex ways Jonathan Lambert/Science News December 5, 2019
This Brainless, Single-Celled Blob Can Make Complex 'Decisions' Yasemin Saplakoglu/Live Science December 2019
Pearl, J. (2018) The Book of Why: The New Science of Cause and Effect. Basic Books, New York.
Prabakaran, S., Dexter, J., & Gunawardena, J. A complex hierarchy of avoidance behaviours in a single-cell eukaryote. Current Biology December 05, 2019
Seligman, MEP, Railton, P, Baumeister, RF and Sripada, C Navigating Into the Future or Driven by the Past. Perspectives on Psychological Science 2013 8: 119
Sweis BM, Thomas MJ, Redish AD (2018) Mice learn to avoid regret PLoS Biol 16(6): e2005853.