If I may quote a Section of PPC Volume 2 :
15.5 What’s in it for the Cell?
The title of this Section was inspired by a message to the CSGnet mailing list by Bruce Nevin (2018.09.11) in which he wrote: This question has long been in my mind: “What’s in it for the cell?”. It refers to the magic of embryology, maturation, learning and healing generally in any multi-celled organism, but here particularly to the cells that constitute the neurological embodiment of a hierarchical perceptual control system.
Living things visible only in the most powerful microscopes are very much simpler than are multi-cellular animals and plants, and yet are subject to many of the same physical constraints as are we. Much of what we discuss in the rest of this chapter will apply equally at multiple levels of size and complexity, from individual cells and their internal structures to identifiable cell assemblies, to organs and body parts, to entire animals and plants, and even to social structures called ecologies in which entire animals and vegetables are the elementary units, and onward to the largest structures that our one world can hold in multiple versions. To the microbes, we are an infrastructural environment that they have built, and they help to maintain us as we maintain our social infrastructure.
So, let us take a brief look into a social structure millions of times smaller than us, that of the cells within any organism. A cell is rather simpler than is the organism of which it is a part, but as with social organisms from slime molds, schooling fishes, hunting wolf-packs and dolphin packs to human families, teams and nations, many individual entities of similar structure may work together to achieve results that they could not achieve by themselves. One person cannot move a Stonehenge-type thirty-ton stone, but a few hundred people can transport it over hilly terrain. The billions of cells in an organism may vastly outnumber the tens of individuals in a social group, but the principles that govern their interactions are close enough to being the same that cells can serve in some important respects as an effective model for human society.
Nevin’s question: “What’s in it for the cell?” has a simple answer that fails, and a more complex answer that succeeds. From the point of view of the cell, it would be bathed in the same nutrients and could receive the same chemical and electrical signals whether or not it participated in the control operations of the organism acting through the organism’s external (possibly social) environment. So the simple answer is that there is nothing in it for the cell. Nothing would (apparently) change for it if it ceased to participate in control or even if its actions proved detrimental to the performance of other controllers. It would be a “cheater” by taking benefits it had not earned by its contribution.
That simple, selfish, answer is the answer that would be seen from the viewpoint of the cell, and it is the same answer that would be given by a person who claims that his or her success was entirely due to their own efforts, while giving no credit to the supporting influences of other people in his or her social environment. A naïve view of Perceptual Control Theory has led some contributors to the CSGnet mailing list to assert that PCT supports such an ultra-libertarian political viewpoint. It is a viewpoint often espoused by very rich people.
Consideration of single isolated control loops, ignoring environmental influences apart from combining them to form “the disturbance”, is certainly consistent with the idea that the individual will — the reference value, applied to the environment with sufficient loop gain eventually through the forces applied by the muscles — is all-powerful. Leni Reifenstahl’s masterful 1935 Nazi propaganda film “The Triumph of the Will” (in the usual English translation of the title) was intended to make this point, though in this case, the “will” was only that of the Great Leader, or Führer, allowing the masses none of their own.
This first answer to Nevin’s question takes the “Controller” viewpoint from inside the cell, but it is just one of the available viewpoints. Two other viewpoints that could offer a different answer are “Observer-Experimenter” and “Analyst-Theorist”, or “See what happens” and “Figure out why things happen”. We have earlier called them just “Observer” and “Analyst” and I will continue to do so. In this case, the Analyst viewpoint comes to a very different answer to Nevin’s question, which the analyst answers “Nothing” and substitutes a slightly variant question: “What’s in it for the cell is survival of cells like itself into the future.” It’s the same answer as one could give to a question: “What’s in it for martyrs who willingly allow themselves to be killed”. “What’s in it for the martyr is survival of people of their kind into the future.”
This does not contradict the simple answer that there is nothing in it for the cell. Rather, it extends it. What’s in it for the cell happened long ago, to its ancestors who survived when others of similar kinds did not. The cell does what it does because way back in history, cells like it, doing what they did, survived because they helped their organisms to survive. The cell benefits by the very fact that it exists, which it does because its properties are like those of its ancestors. If in important ways they are not, it may have few descendants.
The Analyst can see that a cell that contributes to the ability of its organism to maintain its structure by controlling effectively in its environment lives in an organism that has a higher likelihood of survival than would an otherwise identical organism in which that cell exists but has random effects. Those effects might even detract from the ability of the organism to survive. Such a cell may itself live happily in the environment of its organism, but its organism is less likely to survive to produce descendants, because of the energy used in maintaining the cell that does not contribute. Cells that contribute to the welfare of the organism, meaning that they assist in maintaining its structure (their environmental infrastructure), will leave more descendants in the progeny of the organism in which they live.
Even a virus that kills the host organism that provides its necessary infrastructure may prosper individually, but at the expense of its kind if it is so virulent as to deprive its future descendants of hosts. Such a virus type either must find other hosts in which it is less virulent or it will become soon extinct along with its host species.
A popular child’s sing-song taunt is (at least it was popular in my childhood) “Cheaters never prosper”, but experience suggests that in modern Western society this is not true. Like a virulent virus, cheaters often prosper individually; it is the society that includes and allows cheaters that does not prosper. Likewise, a non-contributing cell may save its own energy by not contributing to the survival and prosperity of the organism, but the organism uses energy to maintain that cell. The organism is worse off than it would be if it simply killed the cell, and a lot worse off than in would be if the cell were to begin contributing to its ability to control — enhancing the organism’s “worth” in the language we have been using.
How the society that constitutes the organism achieves this effect is a question about how “policing” systems might have evolved. For the organism, the most effective “policing” is the reconfiguration of the cell to do something useful to the organism, but failing that, removal of the influence of its actions by encapsulating (“imprisoning”) it or killing it also reduces the organism’s energy costs of maintaining the unhelpful cell and of retaining effective control. These policies have their equivalents in most, if not all, human societies and many non-human ones as well.