This is the third of four installments in a blog series by Russell A. Barkley, Ph.D. The full series is titled “Reason is a Type of Evolution (Universal Darwinism).” Dr. Barkley will speak and lead a discussion for RRNA on January 30th, 6:30 p.m., at the Libbie Mill Library. This series is not obligatory reading in order to attend, but it frames and supplements Dr. Barkley’s appearance. The next installment will be posted shortly.

As explained in Parts I and II of this serial blog, anywhere in the universe that information about the environment (knowledge) can be found to have accumulated it will have done so by a Darwinian process of evolution (replication with retention and environmental selection). Therefore, any form of information can evolve provided it is associated with the 9 critical steps that apply to evolution as explained in Part II. In Part III, I explain what may be the different levels of evolution, or the different types of knowledge or information about the natural world that is being accumulated by a process of natural selection.

The general algorithm of evolution explained in Part II is now understood to operate at several different levels, each involving a different type of information (Richards, 1987). Each level is partially dependent on and derived from the levels below it. Also, each higher level has a faster generation (replication and retention) time than those below it. This allows information to be accumulated and refined at an increasingly faster rate than occurs at lower levels of evolution. For instance, at the genetic level of evolution species can take years to reproduce their offspring (copies). Therefore, it can take years, centuries, or millennia for many species to evolve or change and become better adapted to the world. However, even at the genetic level some species are known to replicate quickly (viruses) within minutes to hours. And so they can evolve (and so adapt) more quickly to their environments than can slower reproducing species, such as humans, elephants, and land tortoises. Faster generation times lead to faster evolution by natural selection.

The different levels of Universal Darwinism that have been identified are genetic (slowest)(Dawkins, 1996; Ridley, Mark, 1996), learning by operant conditioning (Skinner, 1981, 1984), vicarious or observational learning (Donald, 1991, 1993), visual imagery or ideational learning (overt and covert rehearsal of ideas or mental representations to the self; a form of mental simulation; Donald, 1991, 1993; Lumsden & Wilson, 1982), gestural communication and language (Blackmore, 1999; Dawkins, 1976), thinking (fastest)(Barkley, 1997, 2001; Popper & Eccles, 1977), and cultural-artifactual (Durham, 1991). Each level relies on a different storage device to both store and accumulate information that has been tested against the environment and retained (or discarded). Each uses a different means of encoding that information. Each uses a different mechanism to replicate or reproduce that information and testing it against the environment. Nevertheless, each is a specific instance of universal evolution in which the environment acts to select which information survives to be retained and replicated in subsequent tests against that environment. Simply put, the environment continuously acts to criticize the information being reproduced at each level. It determines what information survives to get replicated again. All of the steps in the algorithm are believed to exist at each of these levels.

Humans benefit from all levels and modes of this type of informational inheritance (evolution) that results in the accumulation of different forms or levels of information about the environment. Each level provides a progressively more rapid adjustment of the information to changes in its environment – the process of adaptation. That is because at each new level, the time between trials is shortened considerably, permitting the testing of information against the environment to progress more rapidly. More trials can be executed in the same unit of time as we move up to each new level. That leads to faster and faster evolution of that form of information. The number of levels and modes of transmission of information are debatable and unimportant here. What is important is the argument for a general process of Universal Darwinism that governs the acquisition of knowledge (information) about the environment in various forms and at various levels.

Several key ideas should be noted about biological evolution that also apply to Universal Darwinism.

• Different species vary in how many of these levels of universal evolution they possess. Thus they must differ in how rapidly they can accumulate and modify information about and hence adapt to changes in their environment. Humans, in contrast to all other species, benefit from all of these levels, making us among the most adaptable and hence adaptive species on the planet.

• Moreover, as the philosopher Daniel Dennett has argued, freedom evolves. That is, with each new level of informational evolution a species possesses, the more degrees of freedom it has from being controlled by the most immediate or proximal aspects of the surrounding environment. Such freedom does not mean a complete lack of environmental control such that one’s actions are entirely free of influence by the physical environment. But it does mean that such environmental influence or control has been shifted both upward (to higher forms of information), outward (to greater spatial distances and to social others) and forward (across greater temporal distances, or a delayed time period to anticipated future events).

• Furthermore, some of these levels of informational evolution are intra-personal in form (occurring within individuals) (i.e., operant conditioning, ideational [visual-spatial reasoning] and symbolic [linguistic] levels, or individual thinking) and so contribute to the acquisition of personal knowledge about the environment. Other levels are inter-personal or shared and describe the accumulation of information within a pool of knowledge that exists across or among individuals (i.e., gene pools, imitative culture, a common language, archived culture and artifacts such as libraries). While both intra- and inter-individual forms result in the individual having more knowledge about the environment, the second also allows information to be accumulated and stored outside of a person (such as in archives), both across individuals and across generations independent of any single individual. (Note – I believe that there is an alternation occurring between the inter-personal and the intra-personal as new levels of informational evolution come into existence. It is likely that the next level of evolution will occur within some technology device, as in artificial intelligence within a computer.)

Reason (Critical Thinking) is a Form of Universal Darwinism

It is being argued here that reasoning, or critical thinking, and its more systematic and ritualized counterpart known as Science are both a special form of this process of Universal Darwinism. As explained in Part I, Reason and Science are an algorithm that resembles that of evolution – a systematic means by which information about the environment is proposed (replicated), tested against the environment (criticized) for its conformity, selectively retained, mutated (reconfigured from its mistakes) and then proposed and tested again in its modified form. Reasoning occurs within the mind of a person (critical thinking) and is a combination of ideational and symbolic/linguistic levels of evolution though it can also benefit from direct trial and error experience (operant conditioning). The knowledge claim being proposed, tested, mutated, retained and thus evolving over time is retained in the individual brain and is being replicated by that brain through its actions. Yet it can also occur between two people as in discussion and debate where the information is shared between people and retained in their individual brains. Science is the much more systematic, codified, recorded, and cultural version of reasoning where the information that is evolving is subjected to even stricter means of testing and is retained in scientific archives.

The discovery of the specific steps involved in Reason (knowledge evolution) and later Science and their similarity to evolution allowed people to intentionally and more efficiently gather and modify human knowledge about nature rather than accumulate it by trial and error or mere happenstance. In fits and starts, beginning with the Greek philosopher Thales on the importance of criticism to refining human knowledge, as well as other Greek philosophers, our understanding of the nature of Reasoning has progressed. Later this included the philosophical naturalists during the Enlightenment, and then on down to others such as Karl Popper who specifically argued that scientific knowledge is discovered via a Darwinian process (Popper & Eccles, 1977). In discovering the essence of Reason (and later, Science), humans have learned how to intentionally guide a more efficient means of acquiring knowledge concerning the natural world. That use of understanding evolution and using that understanding to guide the acquisition of knowledge is similar to using our knowledge of biological evolution to modify existing species (as in agriculture and animal husbandry) and even to the creation of new species.



Barkley, R. A. (1997). ADHD and the nature of self-control. New York: Guilford.

Barkley, R. A. (2001). Executive functions and self-regulation: An evolutionary neuropsychological perspective. Neuropsychology Review, 11, 1-29.

Barkley, R. A. (2012). Executive Functions: What They Are, How They Work, and Why They Evolved. New York: Guilford Press.

Blackmore, S. (1999). The Meme Machine. New York: Oxford.

Campbell, D. T. (1960). Blind variation and selective retention in creative thought as in other knowledge processes. Psychological Review 67: 380–400.

Dawkins, R. (1976). The selfish gene. New York: Oxford University Press.

Dawkins, R. (1987). The blind watchmaker: Why the evidence for evolution reveals a universe without design. New York: W. W. Norton.

Dawkins, R. (1996). Climbing mount improbable. New York: W. W. Norton.

Deacon, T. D. (1997). The symbolic species: The co-evolution of language and the brain. New York: W. W. Norton.

Dennett, D. C. (1995). Darwin’s dangerous idea: evolution and the meanings of life. New York: Simon & Schuster.

Dennett, D. C. (2003). Freedom evolves. New York: Viking Press.

Donald, M. (1991). Origins of the Modern Mind: Three Stages in the Evolution of Culture and Cognition. Cambridge, MA: Harvard University Press.

Donald, M. (1993). Precis of origins of the modern mind: Three stages in the evolution of culture and cognition. The Behavioral and Brain Sciences 16: 737–791.

Durham, W. H. (1991). Co-evolution: genes, culture, and human diversity. Stanford, CA: Stanford University Press.

Lumsden, C. J., & Wilson, E. O. (1982). Precis of Genes, Mind, and Culture. The Behavioral and Brain Sciences 5, 1–37.

Popper, K. & Eccles, J. (1977). The self and its brain. Berlin/London: Springer-Verlag.

Richards, R. (1987). Darwin and the emergence of evolutionary theories of mind and behavior. Chicago, IL: University of Chicago Press.

Ridley, Mark (1996). Evolution (2nd ed.). Cambridge, MA: Blackwell Science.

Skinner, B. F. (1981). Selection by consequences. Science, 213, 501-504.

Skinner, B. F. (1984). Selection by consequences. The Behavioral and Brain Sciences 7, 477–510.

This blog is an adaptation and updating of material from R. A. Barkley (2012). Executive Functions: What They Are, How They Work, and Why They Evolved. New York: Guilford Press. ©Guilford Press, 2012. Adapted and reprinted with permission.

Dr. Barkley is a Clinical Professor of Psychiatry at the Virginia Commonwealth University Health Center and the Virginia Treatment Center for Children, Richmond, VA.