Do you want to travel through the depths of space and time? Do you want to journey to the edge of the universe and back again? If so, it's a good thing you're a human, because that is exactly what the human mind allows you to do! Our species is uniquely unique precisely because we can escape the confines of the present. And we can escape the confines of the present because we have a "linguistic code."
In the words of anthropologist Jonathan Marks:
"Language permits us to discuss things that didn't happen, that might happen, that will happen."
From a modern perspective, language is essentially an information and communication technology (ICT). Language is perhaps the first, and most fundamental, in a now-long lineage of ICT that make the human animal -- well -- the human animal.
But the origin of this fundamental property of human existence is still shrouded in mystery. Some academics, including the famous linguist Noam Chomsky, believe the origins of human language may forever evade the seemingly never-ending march of scientific understanding.
After all, how can you fully understand the origins of a non-material phenomenon that emerges within mind/brain?
In The Extended Mind, physicist and language theorist Robert K. Logan proposes his model for understanding language: The Extended Mind Model (EMM).
The EMM allows us to understand language within the same framework as we understand the emergence of other communication mediums (e.g., writing) and information technologies (e.g., computer); as an evolved adaptive response to "information overload".
The model first recognizes that language is a medium to organize information and develop ideas. Second, the model proposes that language emerged gradually as hominid social and technical existence on the savannahs of Africa became far more complex than the social and technical lives of any previous hominid species.
So what happened during this communication shift driven by social and technical complexity? Logan asserts that it was a shift from percept-based to concept-based thinking. Percepts (or perceptions) are our sensory impressions of the external world. They are rooted within the present and devoid of abstract symbolic meaning. A perception can be a touch from another person, the sight of a sunset, the smell of a rose. Of course, all animals - including our distant primate ancestors - are/were percept-based thinkers. I know my dog can feel my touch, see me when I walk in the door, or smell my body when I greet her.
But unlike all other animals, humans are also concept-based thinkers. Concepts (or conceptions/conceptualization) are what allow us to deal with the abstract - what is not immediately present. Concepts may be right in front of your nose, at the edge of space-time, and/or anywhere in-between! For Logan, concepts opened up the hominid universe in a way that forever changed human nature.
The empirical and theoretical research from the world of paleoanthropology can certainly work with the EMM to help us understand the emergence of language. All evidence indicates that the world of our ancestors did gradually become more and more complex, both socially and technically. Hominids had started to acquire increased amounts of animal meat with simple technology. This increased group size, which in turn increased technical complexity and hunting ability, which in turn increased group size. This was an autocatalytic process. And it is reasonable to suspect this increase in social complexity led to evolutionary pressures favouring the emergence of a new communication medium and information technology: a conceptually-based language. A way to understand the abstract... what was not immediately present.
Several evolutionary theorists, including paleoanthropologist Robin Dunbar, biological anthropologist Terrance Deacon, and evolutionary psychologist Geoffrey Miller have proposed specific hypotheses that can work within the EMM to explain the specific pressures that led to an "information overload."
Dunbar has proposed the "gossip hypothesis" which asserts that language first functioned as a more-efficient general social bonding mechanism allowing all members of a group to "keep up" with the complex social information required to stabilize a large group. Deacon has proposed the "contract hypothesis," which asserts that language was required to form long-term social contracts (e.g., "marriages") between males and females as brain-size increased. Miller has proposed the "Scheherazade hypothesis" which asserts that language was necessary for males and females to keep each other interested in long-term social bonds as selection for long-term care-givers increased.
In many ways these hypotheses are complementary, as all acknowledge the key theoretical insight that hominid social complexity was increasing dramatically, which in turn increased technical complexity. This confluence of events created Logan's "information overload" and the need for a new communication medium.
In our modern world, language still reigns supreme. Every aspect of our existence is dependent on the ability to think and speak using a conceptual ruled-based linguistic code. We use this code to "extend the mind" beyond the perceptions of here and now. This fundamentally allows for the full expression of human culture and technology. The biggest questions in science now revolve around where that linguistic code can take us!
If you want to read more about the Extended Mind Model, check out Robert Logan's book: The Extended Mind: The Emergence of Language, the Human Mind, and Culture.