What Neuroscience Says About Who We Are: An Episode from David Eagleman’s “Inner Cosmos” Podcast

David Eagleman is a neuroscientist at Stanford University, and he has a podcast called “Inner Cosmos” that I frequently listen to. I was first introduced to his work through his book, Incognito: The Secret Lives of the Brain which was published in 2011, and which I found fascinating.

While I am not a neuroscientist or even a scientist, just an average human being, I have always had an intuitive sense that we cannot control who we are, how we feel, and therefore, what we do. At least, not in the superficial sense of me, let’s say, deciding to go get a cup of coffee right now, but in the more fundamental sense of who I am and what my place in the world is. And that is true for everyone else as well. Nobody can choose whom to be born to or in what circumstances. In fact, we don’t even have a choice in whether to be born or not. Given this, can anyone really be “credited” for being good, or more importantly, “blamed” for being bad?

It has been amazing for me to discover that this intuition — which I had trouble even articulating, let alone sharing with anyone because they would think I was crazy — has now been validated by advancements in neuroscience of the kind Eagleman is researching. He captured some of it in his Incognito book, more of it in one of the earlier episodes of his podcast (Ep15 from July 3, 2023: “What should happen when someone with a brain tumor breaks the law?”), and now, more fully in his recent podcast, “What Does It Mean to Know Thyself?” (Episode website: https://omny.fm/shows/inner-cosmos-with-david-eagleman/ep-29-what-does-it-mean-to-know-thyself-part-1)

While the podcast covers a lot of ground, here are a few things that jumped out at me. Given the complexity of the human brain — it has almost one hundred billion neurons and hundreds of trillions of connections — even very tiny damage to it can have profound changes. So a stroke or a tumor or any other kind of brain injury can change not just your physical and cognitive abilities but your entire personality. The evidence of this can be seen simply by stepping into the neurology ward of any hospital. Of the many examples of this that Eagleman shares with us, one of the most dramatic ones is that of a construction worker called Phineas P. Gage in 1848 who had a tamping rod blast into his skull in an accident, after which he became a completely different person. He was fortunate to survive the accident, but he went from being a smart, capable, affable, respectful, and well-liked person to being uncaring, fitful, irreverent, obstinate, and foul-mouthed. He was so changed and had become so unbearable that the construction company he worked for would no longer employ him.

As Eagleman puts it:

The condition of your brain is central to who you are. You that all your friends know and love cannot exist unless all the fine microscopic details of your brain, all the nuts and bolts, are in place.

Not only do our brains determine who we are, we are not even ordinarily in a position to access it to make changes. This means that who we are remains outside our conscious control. One of the best illustrations of our inability to choose who we want to be is in the arena of romance, in who one is attracted to. As anyone who has ever been lovesick can attest, you can’t “will” yourself to fall out of love, any more than you can “will” yourself to be attracted to someone you are not attracted to. Even if someone put a gun to your head and commanded you to be attracted to someone that you’re not, or to be attracted to a gender that you’re not attracted to, you couldn’t. It simply doesn’t work that way.

Here, again, is a direct quote from the podcast:

Your most fundamental drives are stitched into the fabric of your neural circuitry, and they are inaccessible to you. You can’t reach in there and change them around. You find certain things more attractive than others, and you don’t know why. So, like your nervous system in your gut and your sense of attraction, almost the entirety of your inner universe is foreign to you.

The final topic I wanted to touch upon in this write-up that Eagleman discussed is that of medical interventions and drugs and the impact they have on our brains, and therefore, on ourselves. Some of these are deliberate, like medications developed to treat specific mental-health conditions like anxiety, depression, bipolar disorder, schizophrenia, dementia, and so on. And then, there are drugs like marijuana, cocaine, LSD, etc., all of which have a range of “mind-altering” properties precisely because of which they are used. What medications and drugs have in common are chemicals which interact with the chemistry of our brains and change it to create the indented effect — either of helping with the mental affliction, as with medications, or with inducing feelings of euphoria, as with drugs.

Eagleman describes how exactly an SSRI (Selective Serotonin Reuptake Inhibitor) medication works for treating clinical depression:

Normally, channels called transporters take up the serotonin from the space between the neurons, and when you inhibit that uptake, you get a larger concentration of serotonin in the brain, and the increased concentration has direct consequences on cognition and emotion. People can go on these medications and they can transition from crying on the edge of the bed to standing up and showering and getting their job back and rescuing healthy relationships with the people in their lives, all because of a subtle fine tuning of a neurotransmitter system.

Thank goodness for neuroscience! (That’s me saying this, not Eagleman.)

There is a second part to this “Know Thyself” podcast, in which Eagleman talks about how much of our being is dictated by our genetic makeup, which again, we do not have control over. While it was very interesting and well worth listening to, I found that the crux of the research and findings — at least the part I was interested in — was captured in the first episode.

In conclusion, I wanted to highlight that the intuitive sense of “not being able to control who we are” is not as uncommon as one might suppose and does not always need to be validated by a neuroscientist. For example, I recently read the 2007 novel Slam by Nick Hornby — not a writer known for profound philosophical insights in his books — in which the protagonist, a 17-year-old boy, talks about how he can’t help how he is made: “It’s like a disease or something, not wanting to be bad.” He is comparing himself to a boy who is a bully and who has no qualms about it: “It’s not complicated, being him.” Also: “Life would be easier if I didn’t give a shit, but I do.”

Bottom line — everything we ultimately do and feel is determined by our brain chemistry. And this holds true even for your response in reading this piece!