Chapter 6.     Part B 

Over and over, we act in ways that are not logical by Bayesian standards. We stake the best of our human and material resources on ways of behaving that both reasoning and evidence say are not likely to work. Can Bayesianism account for these glaring bits of evidence that are inconsistent with its model of human thinking?

The answer to this critique is disturbing. The problem is not that the Bayesian model doesn't work as an explanation of human behavior and thinking. The problem is that the Bayesian explanation of human thinking, and the behaviors that result from that thinking, works too well. The irrational behaviors which individual humans engage in are not proof of Bayesianism's inadequacy, but rather of how it applies not only to the thinking, learning, and behavior of individuals, but sometimes moves up a level to the thinking, learning, and behavior of whole communities and even whole nations.

Societies evolve, that is learn and change, in ways that are analogous to the ways in which individuals learn. Like the curious parts of the individual mind, some curious people in society constantly examine and test new ideas and new ways of doing things – getting food, raising kids, fighting off invaders, healing the sick – any of the things that the society has to do in order to carry on. It is also often the case that other sub-groups in society view any new idea or way of doing things as threatening to their most deeply held beliefs. If the adherents of the new idea keep demonstrating that their idea works, and thus, that the more intransigent group’s old ways are obsolete, and if that intransigent sub-group steadfastly refuses to re-write its belief system, then the larger society will usually evolve in a radical way: it will marginalize or ostracize the less effectual members and their system of ideas. In this way, a society mirrors what an individual does when he/she finds a better way of growing onions or or teaching kids or easing Grandpa's arthritic pain. We adapt, as individuals, but also as societies - to cars, television, vaccinations, email, etc. 

  

But then there are the more disturbing cases. Sometimes citizens who keep hanging on to old ways that no longer work, form large minorities or even majorities. 

The Bayesian model of human thinking works well, most of the time, to explain how individuals form and evolve their basic idea systems. Most of the time, it also can explain how a whole community, tribe, or nation can grow and change its sets of nation-wide beliefs, thinking styles, and customs and practices. But can it account for the times when majorities in the community do not embrace new ways even when the Bayesian calculations and the evidence show the ideas to be sound? Can the Bayesian model explain tribalism?

Nazi party rally (1938) Tribalism at its worst 

  

As we saw in our last chapter, for the most part, individuals become willing to drop a set of ideas that seem to be losing their effectiveness when they also encounter a new set of ideas that looks more promising. They embrace the new ideas that perform well, i.e. that guide the individual well, through hazards in real life. Similarly, at the tribal level, whole societies usually drop paradigms, and the ways of thinking and living based on those paradigms, when large numbers of citizens keep seeing that the old ideas are no longer working and that there is a set of new ideas that is getting better results. Sometimes, on the level of changes that sweep across a whole society, this mechanism even means societies marginalize or ostracize sub-cultures that refuse to let go of the old ways. 

But when a new sub-culture with new beliefs and ways keeps getting good results, and the old sub-culture keeps proving ineffectual by comparison, the majority usually do make the switch to the new way …of chipping flint, or growing corn, or spearing fish, or making arrows, or weaving cloth, or building ships, or forging gun barrels, or dispersing capital to the enterprises with the best growth potential.

It is also important to state here that, for most new paradigms and practices, the tests applied to them over the decades only confirm that the old way is still better. Most new ideas fizzle out. Only rarely does a superior one come along.

But the more crucial insight is the one that comes next. Sometimes, if that new paradigm touches on the nation’s most sensitive central beliefs, then the Bayesian calculations about what individuals and their society are going to do next break down. When a new idea challenges those sensitive central beliefs, most citizens continue to blindly adhere to the old beliefs. The larger question here is whether the Bayesian model of human thinking, when it is taken up to the level of human social evolution, can account for these apparently un-Bayesian behaviors. 

     

Many of our most deeply held beliefs are ones that have to do with those areas of our lives that govern our interactions with other humans – family members, neighbors, co-workers, fellow-citizens, etc. These are the areas of our lives which we have long seen, and mostly still see, as being guided not by reason but by “moral beliefs”, beliefs derived in ways that are different from our beliefs about the physical world. In anthropological terms, these are the beliefs that enable the members of the tribe to live together, work as a team, and get along.

The exploitation of women, the execution of murderers, and the other anomalies described in earlier posts are merely consequences of the fact that in spite of our worries about the failures of our moral code in the last hundred years, much of that code lingers on. In many aspects of our lives, we are still drifting with the ways that were familiar, even though our confidence in those ways is eroding around us. We don’t know what else to do. In the meantime, these traditional ways are so deeply ingrained and familiar as to seem natural, even automatic, for many people, in spite of evidence to the contrary.

What we are dealing with when we study the deepest and most general of these "traditional" behaviors and beliefs are those beliefs that are very deeply programmed into every child by all of the tribe’s adult members. These beliefs aren’t subject to the Bayesian models and laws which usually govern the learning processes of the individual human. In fact, they are almost always viewed by the individual as the most profoundly important parts of his culture and himself. They are guarded in the psyche by layers and layers of emotional associations containing anger and fear. They are the beliefs and practices that your parents and your teachers and your storytellers and your leaders enjoined you, with great passion, to hang on to at all cost. For most people in most societies, these beliefs and their attached morés are viewed as being simply and truly “normal” and “human”.

    

Our meta-belief, that is to say our belief about our moral beliefs, for centuries, was that they were set down by God and, therefore, were universal and eternal. When we made such a distinction, we were in effect, placing our moral beliefs in a separate category from the rest, one meant to guarantee their untouchability.

  John Stuart Mill 

But are our moral beliefs really different in some fundamental way from our beliefs in areas like Science, Athletics, Automotive Mechanics, Farming, or Cooking? The answer is ‘Yes and no’. Better farming practices and medical procedures we are eager to learn, and who doesn’t want to win at the track meet? But about the executing of our worst criminals or the exploitation and subjugation of women, however, many in our society are more reluctant to change. Historical evidence shows societies can change in these sensitive areas of their lives, but only grudgingly. (John Stuart Mill discusses the obstinacy of old ways of thinking about women, for example, in the introduction to "The Subjection of Women".) (3.)

  

These beliefs which humans hold most deeply, the ones that most obstinately resist change in the belief set shared by a whole nation, are ones that are nearly impossible to amend by rational persuasion of individuals. They only get eradicated at all if they are eradicated from a whole nation when they no longer work. They fail to provide effective real-world guidelines by which the humans who hold them can make choices, act, and live their lives. They fail so totally in this role that the people who hold the old values begin to die out. They die young, or fail to reproduce, or fail to program their values into their young, or the whole tribe may even be overrun. By one of these mechanisms, a tribe’s whole culture and values system can finally die out. The genes of the tribe may go on in kids born from the merging of two tribes – the victors and the vanquished – but one tribe’s set of beliefs, values, and morés, i.e. its culture, becomes a footnote in history. 

Notes 

3. http://www.constitution.org/jsm/women.htm