One point which I've made on this weblog several times is that on a whole range of issues and behaviors people simply follow the consensus of their self-identified group. This group conformity probably has deep evolutionary origins. It is often much cognitively "cheaper" to simply utilize a heuristic "do what my peers do" than reason from first principles. The "wisdom of the crowds" and "irrational herds" both arise from this dynamic, positive and negative manifestations. The interesting point is that from a proximate (game-theoretic rational actor) and ultimate (evolutionary fitness) perspective ditching reason is often quite reasonable (in fact, it may be the only feasible option if you want to "understand," for example, celestial mechanics). If you're faced with a complex environment or set of issues "re-inventing the wheel" is often both laborious and impossible. Laborious because our individual general intelligence is simply not that sharp. Impossible because most of us are too stupid to do something like invent calculus. Many people can learn the rules for obtaining derivatives and integrals, but far fewer can come up with the fundamental theorem of calculus. Similarly, in the 18th century engineers who utilized Newtonian mechanics for practical purposes were not capable of coming up with Newtonian mechanics themselves. I'm using these two examples because calculus and mechanics are generally consider "high level" cognitive tasks, but even they at the root illustrate the principle of collective wisdom and group conformity. Calculus and mechanics is included in the curriculum not because all of the individuals who decide the curriculum understand these two topics in detail, but because individuals whom they trust and believe are worthy of emulation and deference, as well as past empirical history, tell them that this is the "reasonable" way to go. (science and engineering have the neat property is that you don't just trust people, you trust concrete results!) This sort of behavior is even more evident in political and social viewpoints. Recently there have been signs of shifts in African American attitudes toward same-sex marriage, and a more general trend in that direction across the population. Is this because individuals are sitting in their armchair and reflecting on justice? Of course people will enter into evidence the experience of knowing gay people, and the empathy which that generates, but are you willing to bet that these public policy shifts are primarily and independent driven by simply these sorts of dynamics? (i.e., run a regression and trying predict the change in attitude by the number of people coming out of the closet over time) Similarly,people like Chris Mooney have documented the shift among the Republican grassroots in issues like climate change which seem to have moved very rapidly likely due to elite cues, rather than a deep analysis of the evidence. But let's look at something less controversial, at least on this weblog. Most people who accept evolution really don't understand how it works, nor are they very conversant in the reasons for why evolutionary process is compelling. The vast majority of the 50 percent of Americans who accept evolution have not read Charles Darwin, nor could they tell you what the neo-Darwinian Synthesis is. They have not read Talk Origins, or Why Evolution is True. So why do they accept evolution? Because evolution, like Newtonian mechanics, is part of established science, and educated people tend to accept established science. But that's conditional. If you look in the General Social Survey you notice a weird trend: the correlation between education and acceptance of evolution holds for those who are not Biblical literalists, but not for those who are Biblical literalists! Why? Because well educated Biblical literalists accept a different set of authorities on this issue. In their own knowledge ecology the "well-informed" perspective might actually be that evolution is a disputed area in science. At this point everything is straightforward, more or less. But I want to push this further: most biologists do not understand evolution as a phenomenon, though they may be able to recall the basic evidence for evolution. If you are working in molecular biology, medical research, neuroscience, etc., there isn't a deep need to understand evolutionary biology on a day to day basis on the bench (I would argue the rise of -omics is changing this some, but many labs have one or two -omics people to handle that aspect). The high rates of acceptance of evolution among researchers in these fields has less to do with reason, and more to do with the ecology of ideas which they inhabit. Evolutionary biologists in their own turn accept the basic structural outlines of how axons and dendrites are essential in the proper function of the brain without understanding all the details about action potentials and such. They assume that neuroscientists understand their domain. So far I've been talking about opinions and beliefs that are held by contemporaries. The basic model is that you offload the task of reasoning about issues which you are not familiar with, or do not understand in detail, to the collective with which you identify, and give weight to specialists if they exist within that collective. I would submit that to some extent the same occurs across time as well. Why do we do X and not Y? Because in the past our collective unit did X, not Y. How persuasive this sort of argument is all things equal probably smokes out to some extent where you are on the conservative-liberal spectrum. Traditional conservatives argue that the past has wisdom through its organic evolution, and the trial and error of customs and traditions. This is a general tendency, applicable both to Confucius and Edmund Burke. Liberal utopians, whether Mozi or the partisans of the French Revolution, don't put so much stock in the past, which they may perceive to be the font of injustice rather than wisdom. Instead, they rely on their reason in the here and now, more or less, to "solve" the problems which they believe are amenable to decomposition via their rational faculties. Both methods of coming to a decision result in errors, at least in hindsight. I argue at Secular Right that American conservatives should just accept that they were on the wrong side of history on Civil Rights, just as 19th century conservatives were often on the wrong side of history on slavery. In fact, it is the latter case which is more interesting, because slavery was accepted as a viable institution in all civilized societies up until that era (even if it was perceived as an evil). Yet today we can agree that the collective wisdom of the ages was on some level wrong-headed. Does that then mean that we should rush to every new enthusiasm and establish justice in our time? Obviously as someone who identifies as conservative I do not. Just as conservatives have been wrong in the past on relying upon the wisdom of the past, liberals have been wrong about their grasp of the details of the architecture of human reality in their own age. Though Edmund Burke defended institutions which we might consider retrograde, in broad strokes his criticisms of the excesses of the French Revolution were spot on. The regime which abolished slavery and emancipated Jews also ushered in an age of political violence which served as the template for radicals for generations. French Jews may have been more fully liberated before the law at an earlier period than British Jews, but were French Jews more accepted within French society one hundred years later than British Jews? More recently progressives and liberals accepted the necessity of coercive eugenics as part of the broader social consensus in the West (which only a few institutions, such as the Roman Catholic Church, resisted with any vigor). Obviously this specific reliance on reason and rational social engineering was perceived to be a failure. Less controversially, some of the excesses of the Great Society and the 1960s revolution in the United States in the area of social welfare and criminal justice seem to have exacerbated the anomie of the 1970s, which abated concomitantly with the rollback of open-ended nature of the welfare state and tougher law & order policies in the 1990s. Even the most well conceived experiments sometimes end up failing. Whatever your political or social perspective, the largest takeaway is that attitudes toward complex issues which are relevant to our age are almost always framed by the delusion that reason, and not passion, has us by the leash. The New Right which championed the "pro-life" movement in the late 1970s, and the progressive Left which espouses "marriage equality" now, can all give individual reasons when prompted why there was a shift in opinion. But the reasons proffered will be interestingly invariant, as if people are reading off a collective script, which they are. Social milieus can sometimes crystallize consensus so quickly that individuals caught in the maelstrom of the new orthodoxy construct a whole internal rational edifice which justifies their conformity. This does not mean that the conformity and the viewpoints are frauds, just that as humans we tend to self-delude as to the causal chain by which we come to our conclusions.