The Thought-Provoking History of Thought

by Michaela Barillos

Hiraya Zine
6 min readJan 25, 2022


This article is an exclusive first look at Hiraya Zine’s latest issue. Volume 2 Issue 1: Origin of Origins is arriving on January 26, through Gumroad.

Art by Andie Peñaflor for Hiraya Zine.

Think big,”think outside the box,” “think on your feet,” “I think, therefore I am” — these are perhaps some of the most overused idioms of the English language to date. Coincidentally, they are also tied with our capacity for thinking.

Speaking of capacity, a recent study suggests that on average, humans have 6,200 thoughts per day. That shows how high our capacity is. It also speaks a lot about how occupied our species are with so many things — things that trigger the processes that produce this vast stream of ideas. But what are these processes? Where do they come from? How do they exist? Can we trace the root of all human thought?

Before we leap to these big questions, let’s start with a simpler one, what is a thought?

The Many Thoughts About Thoughts

Photo via Unsplash/Egor Myznik

Thoughts are so complex that until now, there is still no consensus on how it is defined nor understood. Dictionaries denote them as ideas, images, or emotions generated by the act of thinking. Some experts explain thoughts as representations that depict things our brains perceive when triggered by stimuli. Others describe them as the cognitive or emotional state of a living being.

Earlier theories suggest that thoughts are forms of inner speech in which the individual subvocally organizes linguistic elements to form mental sentences. Elementary experiments showed the correlation between thinking and muscular activity in the individual’s articulators (e.g. tongue, throat). It later became evident through a series of latter experiments that thoughts and speech occur separately, although scientists still acknowledged the interdependence of these activities.

It is also held that thought doesn’t simply emerge in the confines of the brain and that a person thinks with their whole body. This is forwarded by recent studies which unveiled a network of neurons in the stomach, also identified as the “brain in the gut.” This belief is related to the behaviorist approach, which, like its term suggests, states that thought is a behavior or that thinking corresponds to a certain behavior or action.

How are thoughts formed?

Electric signals deliver information through our nervous system. Illustration via Unsplash/Hal Gatewood

There are plenty of competing ideas out there attempting to unlock the enigma of thought process, but the general claim is that external stimuli — everything that our senses can detect, directly evoke a train of signals that will lead to the formation of thought. When reading a book, for example, the photons of the patterns of the letters reach the retina, and their energy sparks off electrical signals in the photoreceptors (specialized cells in the retina that respond to light). The signals would travel along the axon, prompting the release of neurotransmitters that would relay the message into the synapse (small spaces that act as mediators between neurons). Once these impulses reach a target neuron, the neuron responds and spreads its own signals to hundreds of thousands of neighboring neurons in several coordinated areas of the brain, allowing you to identify and think about the words.

More explicitly, neurons fire during the thought formation process. Your external environment triggers a succession of neuron firing, and this interplay between neurons eventually forms a thought.

In 2016, Paul Slesinger and his fellow neuroscientists at Icahn School of Medicine at Mount Sinai were able to further this theory and clearly examine brain activity using cell-based neurotransmitter fluorescent engineered reporters, or CNiFERs. They are currently being used as mediums to oversee neural processes over long periods of time. CNiFERs glow when it makes contact with the neurotransmitter it is detecting. And with the help of a tiny sensor implanted in the brain, scientists, in turn, can assess how bright the CNiFER lights flare to presume the number of neurotransmitters present during the brain activity.

The Root Thinkers

Shell of a thought. Photo via Unsplash/Trnava University

It is a rich tradition for everyone to look back upon our history. Because of that, we were able to infer the origin of origins, a.k.a. the beginning of our universe, the beginning of life, and then the beginning of our species. Surely after all that it’d be relatively easier to find out the first-ever thought or the first-ever thinker that made all the other members of our species a thinker, right?

Nope. In truth, the origin of thought is still as puzzling as time itself. Thought is ultimately a highly internal and individualized process that leaves no physical, observable trace in the annals of history. But thanks to advancements in technology, scientists suspect that human-like thought emerged about 1.8 million years ago.

In a recent study by Shelby S. Putt with The Stone Age Institute at Indiana University, volunteers were taught to construct two ancient tools: Oldowan tools from 2.6 million years ago, and Acheulian hand axes which date back to 1.8 million to a hundred thousand years ago. Their brain scans revealed that making Acheulian tools required a higher level of cognition than Oldowan tools. And since one characteristic of humans is an advanced form of cognition, scientists concluded that humanlike thought likely emerged at least 1.8 million years ago.

However, these findings still don’t answer when, how, where, or what thoughts emerged, regardless of whether it is apelike or not. The only obvious, plausible guess left is that thought began with life itself when organisms moved and found ways to adapt and thrive in their environment.

A Final Thought

Photo via Unsplash/Greg Rakozy

When understood in a general and objective sense, thoughts are simply the natural products of our brain activity. This involves the interaction between hundreds of thousands of neurons throughout our nervous systems. Even the simplest, arbitrary thoughts about “Shrek” or “hotdog” already consist of a myriad of complex structures at play. This entire process in our heads is influenced by everywhere, by everyone, and by everything that has a causal relationship with us, our societies, and the entirety of mankind.

We’re still a long way from developing a nuanced understanding of thought as a whole, but the silver lining here is that aspiring scientists can have more untapped areas to explore where they can develop a successful, novel theory that could untangle the long-standing riddle of thought. Who knows? You might just be one of them.

The greatest mystery mankind has ever encountered might be something that’s just well within the bounds of their own minds.




Hiraya Zine

Flagship project of SciCreate, bridging the gap between researchers and the youth through the use of art, writing, and the humanities in quarterly zine issues.