The human mind is not an instrument for discerning the truth. It is an instrument of survival. You may be assuming that evolving for these two purposes would produce equivalent minds, or minds with equivalent functionality, but that is not the case. There are subtle and important differences between the truth that is believed by a mind that is designed to survive and the truth believed by a mind that is designed to understand the truth as such. In particular, if understanding certain types of concepts would produce behaviors detrimental to the survival of the individual, I expect that evolved minds will fail to support that understanding.
The human brain is not an especially logical instrument. I’m not sure what modern philosophical scholarship on this subject says, but I know this is a popular misconception, and for certain that idea was presupposed and even enshrined by most ancient and enlightenment era philosophers. We should be able to dispense with the notion readily by observing that natural selection’s principles operate on the human brain – if the brain is not a divine construction, and it is purely the result of natural selection, then clearly it is first and foremost an adaptive instrument, and any ability to access facts or ascertain truth is enthralled to the primary purpose of survival; we have no reason to assume that those aims coincide in every case.
Now, why does a significant majority of the human population believe in the existence of a deity? Why do any religions exist? If we choose to set aside for the moment any value judgement about religions we would feel safe in assuming that – for whatever reason – it’s most likely adaptive to be religious – or at the very least to possess a mind that is receptive to religion and superstitions. Natural selection(or in this case cultural or mimetic selection) apparently must have some preference for this. And I’m also going to suggest that this is not a retained archaic trait (that at some time in the past it was necessary, but is now unnecessary and vestigial, and that people who were raised without religious belief or have left it behind are somehow more “evolved”). That would speak to a lack of understanding of the process, because evolution does not produce superiors from inferiors – it produces adaptations and improvements to adaptations, always in response to some constraint and environmental demand. Adaptations have a value only measurable in the terms of specific environments.
With those two points established, I move on to the third:
Selective pressure does not necessarily act homogeneously across the population. It may be nature’s preference to have some distribution of traits.
The above is a consequence of a more basic idea, namely that natural selection is scale-free, which would be better explored in another post. For now, I’m satisfied with asserting that selection acts on integrated systems of living organisms while simultaneously acting on those organisms individually, producing system-wide adaptations. This is closely associated with “group selection.” Group selection is well explored in biology, but in that literature it seems to be common to discuss it as a mechanism for the evolution of altruism and prosocial behaviors. Here I am suggesting not just that group dynamics generate selective preference for individual behaviors, but that selective preference exists for behaviors of the group concurrently.
With those two facts and the above (unqualified) assertion, I arrive at the central point:
Acting on entire systems of human communities, selective pressure has worked to produce a variety of intellectual styles that constitute an adaptation of the system as a whole.
The system is the unit of selection. Just as the organs in the bodies of vertebrates have differentiated and component-ized to act in concert as part of the whole, so I suggest here that natural selection has worked on communities to produce a diversity of intelligences, the interaction and relation of which produce adaptive community scale behavior.
In this hypothesis, I identify only two general types of “intelligences.” Alternatively, I may call them “epistemological approaches”, or “intellectual dispositions”. The distinction is made entirely by what someone identifies as valid sources and justifications for their knowledge.
In type A, which constitutes the majority of people, knowledge is developed primarily through a social praxis. If knowledge is justified true belief, group A finds ideas and facts from books and other communication media, and sufficient justification through authority and prevailing social norms.
In type B, which is kept at a minority, appeals to authority are immediately discarded. New knowledge is gained overwhelmingly in a more empirical way, outside of the social praxis – the popular views are irrelevant for this disposition. These people are the experimenters – not exclusively in the scientific context, but with all types of ideas. For this reason, it is these people who generally produce new knowledge.
Let me take a moment to get away from the assumption that people should be categorizable as ‘A’ or ‘B.’ I only want to suggest that in a particular context a person will either adopt an A or B disposition, or that one type of approach may be a person’s habit(1).
Is it apparent why it should be preferred that type A be the more common? Because the B disposition is less receptive to beliefs that come in through social channels, it is actually less likely to facilitate the propagation and preservation of culture. The continued development of the scientific enterprise, and even the continued growth of other forms of mimetic innovation require that humans communicate culture amongst each other and through generations with limited resistance. The B disposition is a source of attenuation.
The interplay of the two styles then becomes clear: one sector of the community, operating at the boundaries of human knowledge, acts with the style that is best for generating new understanding. That new knowledge or innovation must then be passed into the larger corpus for preservation. Knowledge will not be well maintained in a system of interacting people unless enough of them operate under disposition A. One part of the community must learn, the other part must remember(2).
Extravagantly, I claim that these dynamics have generated the observed distribution of “intelligences”: The greater bulk of the population accepts the knowledge that is given by the dominant culture around them(3). Some minority exists, and persists(by selection acting at scale) to facilitate changes to that dominant culture, and as generations pass, innovations are passed from the fringe back into the greater community where memory is better held. The entire group of people thereby adapts to ever harsher and more diverse environments, and as will be seen…better competes with other groups.
1. And it should be noted that in whatever sphere a person does not exercise group B thinking, they are defaulting to group A. For example, there may be a mathematician, very esteemed in her field, who is at all times habitually ‘B’ thinking when working on problems in mathematics or reading journal articles, but this same person is not likely an expert in, for example, biology. If there is some commonly accepted belief appearing in textbooks on the subject, it may not be her habit to question that knowledge, as it lies outside the scope of her own ‘B’ habits – and therefore in most spheres outside mathematics she is in group A. I am not sure what it implies about my hypothesis if even all ‘B’ thinkers are group ‘A’ thinking in most situations. There may not be a viable mechanism for biological selection in that case.
2. To avoid a going off on a tangent here I pretend like I didn’t just describe human communities’ behavior as being itself brain-like. That is, again, another post altogether, and I’m sure there are many better written and more credible sources for interesting material in this vein than this blog.
3. I don’t just mean religious people as I indicated above. There are a number of people, for example, who say they believe in evolution, but only have a very superficial understanding of the process or the evidence by which it is known to occur. Although it may be a true belief, they have not justified it independently, and therefore in that case operate under the ‘A’ disposition. Over time, it is expected that a popular belief in evolution will eventually overtake the popular belief in creationism(in the U.S.), though people’s habits of thinking will remain as unscientific as before.