The Open Mind

Cogito Ergo Sum

Archive for March 2014

The Co-Evolution of Language and Complex Thought

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Language appears to be the most profound feature that has arisen during the evolution of the human mind.  This feature of humanity has led to incredible thought complexity, and also provided the foundation for the most simplistic thoughts imaginable.  Many of us may wonder how exactly language is related to thought and also how the evolution of language has affected the evolution of thought complexity.  In this post, I plan to discuss what I believe to be some evolutionary aspects of psycholinguistics.

Mental Languages

It is clear that humans think in some form of language, whether it is accomplished as an interior monologue using our native spoken language and/or some form of what many call “mentalese” (i.e. a means of thinking about concepts and propositions without the use of words).  Our thoughts are likely accomplished by a combination of these two “types” of language.  The fact that young infants and aphasics (for example) are able to think, clearly implies that not all thoughts are accomplished through a spoken language.  It is also likely that the aforementioned “mentalese” is some innate form of mental symbolic representation that is primary in some sense, supported by the fact that it appears to be necessary in order for spoken language to develop or exist at all.  Considering that words and sentences do not have any intrinsic semantic content or value (at least non-iconic forms) illustrates that this “mentalese” is in fact a prerequisite for understanding or assigning the meaning of words and sentences.  Complex words can always be defined by a number of less complex words, but at some point a limit is reached whereby the most simple units of definition are composed of seemingly irreducible concepts and propositions.  Furthermore, those irreducible concepts and propositions do not require any words to have meaning (for if they did, we would have an infinite regress of words being defined by words being defined by words, ad infinitum).  The only time we theoretically require symbolic representation of semantic content using words is if the concepts are to be easily (if at all) communicated to others.

While some form of mentalese is likely the foundation or even ultimate form of thought, it is my contention that communicable language has likely had a considerable impact on the evolution of the human mind — not only in the most trivial or obvious way whereby communicated words affect our thoughts (e.g. through inspiration, imagination, and/or reflection of new knowledge or perspectives), but also by serving as a secondary multidimensional medium for symbolic representation. That is, spoken language (as well as its subsequent allotrope, written language) has provided a form of combinatorial leverage somewhat independent of (although working in harmony with) the mental or cognitive faculties that innately exist for thought.

To be sure, spoken language has likely co-evolved with our mentalese, as they seem to affect one another in various ways.  As new types or combinations of propositions and concepts are discovered, the spoken language has to adapt in order to make those new propositions and concepts communicable to others.  What interests me more however, is how communicable language (spoken or written) has affected the evolution of thought complexity itself.

Communicable Language and Thought Complexity

Words and sentences, which primarily developed in order to communicate instances of our mental language to others, have also undoubtedly provided a secondary multidimensional medium for symbolic representation.  For example, when we use words, we are able to compress a large amount of information (i.e. many concepts and propositions) into small tokens with varying densities.  This type of compression has provided a way to maximize our use of short-term and long-term memory in order for more complex thoughts and mental capabilities to develop (whether that increase in complexity is defined as longer strings of concepts or propositions, or otherwise).

When we think of a sentence to ourselves, we end up utilizing a phonological/auditory loop, whereby we can better handle and organize information at any single moment by internally “hearing” it.  We can also visualize the words in multiple ways including how the mouth movements of people speaking those words would look like (and we can use our tactile and/or motor memory to mentally simulate how our mouth feels when these words are spoken), and if a written form of the communicable language exists, we can actually visualize the words as they would appear in their written form (as well as the aforementioned tactile/motor memory to mentally simulate how it feels to write those words).  On top of this, we can often visualize each glyph in multiple formats (i.e. different sizes, shapes, fonts, etc.).  This has provided a multidimensional memory tool, because it serves to represent the semantic information in a way that our brain can perceive and associate with multiple senses (in this case through our auditory, visual, and somatosensory cortices).  In some cases, when a particular written language uses iconic glyphs (as opposed to arbitary symbols), the user can also visualize the concept represented by the symbol in an idealized fashion.  Associating information with multiple cognitive faculties or perceptual systems means that more neural network patterns of the brain will be involved with the attainment, retention, and recall of that information.  For those of us that have successfully used various pneumonic devices and other memory-enhancing “tricks”, we can clearly see the efficacy and importance of communicable language and its relationship to how we think about and combine various concepts and propositions.

By enhancing our memory, communicable language has served as an epistemic catalyst allowing us to build upon our previous knowledge in ways that would have likely been impossible without said language.  Once written language was developed, we were no longer limited by our own short-term and long-term memory, for we had a way of recording as much information as possible, and this also allowed us to better formulate new ideas and consider thoughts that would have otherwise been too complex to mentally visualize or keep track of.  Mathematics, for example, exponentially increased in complexity once we were able to represent the relationships between variables in a written form.  While previously we would have been limited by our short-term and long-term memory, written language allowed us to eventually formulate incredibly long (sometimes painfully long) mathematical expressions.  Once written language was converted further into an electro-mechanical language (i.e. through the use of computers), our “writing” mediums, information acquisition mechanisms, and pattern recognition capabilities, were further aided and enhanced exponentially thus providing yet another platform for an increased epistemic or cognitive “breathing space”.  If our brains underwent particular mutations after communicable language evolved, it may have provided a way to ratchet our way into entirely new cognitive niches or capabilities.  That is, by communicable language providing us with new strings of concepts and propositions, there may have been an unprecedented natural selection pressure/opportunity (if an advantageous brain mutation accompanied this new cognitive input) in order for our brain to obtain an entirely new and possibly more complex fundamental concept or way of thinking.


It seems evident to me that communicable language, once it had developed, served as an extremely important epistemic catalyst and multidimensional cognitive tool that likely had a great influence on the evolution of the human brain.  While some form of mentalese was likely a prerequisite and precursor to any subsequent forms of communicable language, the cognitive “breathing space” that communicable language provided, seems to have had a marked impact on the evolution of human thought complexity, and on the amount of knowledge that we’ve been able to obtain from the world around us.  I have no doubt that the current external linguistic tools we use (i.e. written and electronic forms of handling information) will continue to significantly alter the ongoing evolution of the human mind.  Our biological forms of memory will likely adapt in order to be economically optimized and better work with those external media.  Likewise, our increasing access to new types of information may have provided (and may continue to provide) a natural selective pressure or opportunity for our brains to evolve in order to think about entirely new and potentially more complex concepts, thereby periodically increasing the lexicon or conceptual database of our “mentalese” (assuming that those new concepts provide a survival/reproductive advantage).