"Without the theory of evolution by memetic selection nothing in the world of the mind makes much sense. " - Susan Blackmore

The human species is defined by technology, having an ability to create complex technology that far exceeds that of any other animal. No other animal comes close to the human capacity to produce artefacts, and this makes humans unique in the animal kingdom. This unique human capacity for complex technology is the result of meme-based intelligence that also exceeds that of any other animal.

While memes as replicators predate the human species and exist across the animal kingdom, they have in the human species gone through an evolutionary leap, similar to the leap from primitive life forms to multi cellular life in the early primordial seas. Like DNA found an environment where it could grow into animals, plants, fungi and bacteria, memes as a new form of replicator have flourished in the human brain, acting as the "genetic code" for technology, analogous to how proteins are encoded in genes.

What exactly were the evolutionary adaptations that turned the human brain into a primordial sea for memetic evolution? Having defined the result, I will suggest a theory for how humans got there, by hijacking their primary sensory modality and turning its attention inwards onto the contents of the mind, trading olfaction for ideas.

Did humans trade olfaction for ideas?

“The human mind is an inadequate agent with which to study olfaction, for the reason that the human olfactory system is relatively insignificant, and that of the other animals give them powers far beyond our comprehension” — Charles Judson Herrick, 1924

What is the cognitive system humans use when manipulating ideas? Humans have over the past 4 million years gained an ability to manipulate ideas that far exceeds any other animal, and have used that ability to develop complex technologies. How exactly has the human species been able to do that, and what is the cognitive system it has evolved for that?

In psychiatric science, the field of medical science that studies “disorders” of the ability to manipulate ideas, the concept of “executive function” has gradually developed over the past 50 years, first defined by psychiatrist Karl Pribram in 1973. This “executive function” has the properties that when it is impaired by coercive government, the brain loses the ability to organize the mind, and develops mental illness or “meme illness”. These observations, documented and recorded in history itself, suggest that the human executive function is the cognitive system that led to advanced memetic intelligence in humans. What is the evolutionary history of this cognitive system?

The neural circuits that have been assigned to the executive function show an overlap with the neural circuitry of the mammalian olfactory system (Fagundo, 2015). Olfaction is the primary sensory modality in mammals (Slotnick, 2009), but not in humans. Not only have humans lost a large part of their olfactory receptors in the past 4 million years (Gilad, 2003; Hughes, 2014), they have also lost most of their olfactory intelligence (Sela, 2010). These observations could be explained with that this primary sensory modality, the olfactory system, was “turned inwards”, its attention pointed towards a non-physical environment, the world of ideas, and that the human executive function is a derived trait that co-opted the mammalian olfactory system.