"The remarkable thing is that although basic research does not begin with a particular practical goal, when you look at the results over the years, it ends up being one of the most practical things the government does."

-Ronald Reagan

Yes, the above quote is from that Ronald Reagan. Oh, the irony, eh?

The accelerating pace of neuroscience in the last few decades has yielded extraordinary insights into the nature of human intelligence. What was once the exclusive domain of philosophical conjecture—questions about the source, stability, and limits of human cognition—has now become increasingly susceptible to empirical inquiry. Advances in neuroimaging, psychometrics, and genetics have fueled this shift, overturning many of our long-held intuitions about the mind and its potential. And yet, our discourse—both scientific and public—has failed to fully integrate these findings, leaving us in a state of moral and political dissonance.

Recently, I read The Neuroscience of Intelligence (part of the Cambridge series of neuroscience of psychology) by Richard Haier of the University of California, Irvine. A sweeping overview of the landscape of intelligence in neuroscience (duh), the pages are absolutely crammed full with experiments, explanations, data, interpretations, and theory; it's a lot to take in. Several of my moral and philosophical presuppositions—those of intelligence, social outcomes, and the malleability of individual potential—were exposed. Unsurprisingly, when I think about it, the book augmented some other views I have. Reexamination of assumptions is rarely a waste of time, however.

It is no small thing to realize that much of what we consider solvable through intervention may, in fact, be underwritten by a genetic architecture far more resistant to change than we had hoped. The implications are profound. If the boundaries of intelligence are more constrained than commonly thought, it may be that we need to rescope our ambitions for public policy and social programs. The prevailing assumption has been that, with the right combination of investments in education and social opportunity we can significantly uplift cognitive outcomes across populations. To be clear, this is mostly an examination of Tabula rasa theories, but I will flirt a bit with politics. Hopefully my positions are rational enough to be acceptable and worth thinking about, even if you disagree on various levels.

PFIT (Parieto-Frontal Integration Theory)

The core of Parieto-Frontal Integration Theory proposes that there are a number of regions in the brain that underlie intelligent behavior and there is a clear, structured flow, form and function. Imaging research, lesion studies, and psychometrics provide the multidimensional evidence supporting PFIT. Sensory data percolates through the parietal lobe and is elaborated on by the frontal lobe, with interactions between the two generating evaluations and calculations and the anterior cingulate cortex playing a role in inhibiting or promoting responses. There is a general consensus that the PFIT is seen as the "best available answer" to the question of "where" in the brain intelligence resides, with a hint of "how" intelligence works.

Haier's overview teases out a few key concepts:

Structure and Function

Intelligence is a physical, specifically biological, phenomenon. Variance in intelligence is strongly linked to brain structures like gray matter, cortical thickness, efficiency, and white matter integrity. Intelligence can be measured relatively well through psychometrics or chronometrics and is individually stable. While measurements of intelligence remain stable, under nuanced circumstances like learning new skills, it may be moderately improved in some areas. Less activity, in some regions and under some circumstances, correlates to higher IQs in many cases (again, with nuance), suggesting that efficient networks play a part in intelligence. These metrics strongly predict outcomes like school achievements and socioeconomic status (however, there is much to dig into and many confounds to address with that correlation).

Genes' Major Role

Genes and gene expression, not environment, overwhelmingly drive variance in intelligence. While the genes-to-intelligence relationship remains controversial politically, it is not so scientifically. We will benefit from redressing valid concerns given past historical misuses, terrible ethics of intelligence research and treatment of disadvantaged research subjects. The most compelling evidence for genes' dominant role is studies on identical twins raised apart and children raised in different homes from their parents. These frameworks of experiment (twin, adoption and sibling) are considered a gold standard for gene and gene expression studies. The correlation coefficient of intelligence is about 77%, having been replicated time and time again with increasingly large population studies. Despite the ongoing failure to identify even a single gene as one that is definitively responsible for differences in intelligence, Haier relays that intelligence is suspected by many to be pleiotropic (one intelligence gene could affect many dissimilar traits) and broadly accepted as polygenic (many genes contribute in a lot of small ways to overall intelligence). Epigenetic variances remain a wrinkle to unravel, but even so, it is clear that environment is operating on the biological material it has at hand.

Environment's Relevance

The same studies that point to genes' influence also point to environment playing a role, but the role is nuanced. Nutrition, stable learning environments, and socioeconomic status all influence cognitive development. Early on, differences in environment account for a high percentage of differences in intelligence (around 75% at age 5!), but this drops to less 20 percent by age 18. Environment platforms development, but its reach is weaker than once believed. Early interventions, such as heavy investment in childhood programs aimed at raising latent ability (with the most obvious outcome being higher test scores), have yielded tepid and limited results. With more understanding of the biological substrate of intelligence, this could change. Worth mentioning is the Flynn effect, an unresolved phenomenon. This is certainly worth finding causal factors of, but as of yet, it doesn't refute the genetic/biological evidence. Likely, it simply reinforces the first and second sentences of this paragraph.

Enhancement is Limited

So far, putative intelligence improvement through brain-training and enhancement abilities are limited, despite a robust industry built around this premise. While it was hoped that we might find low cost, low effort interventions like memory training or listening to Mozart, many experimental results have only offered modest but temporary improvements at best, and simply even left the realm of statistical standard error at worst. Researchers have shifted their hopes toward biological interventions, with some extremely interesting pathways in development. Check out DREADD (classes of synthetic, engineered neuronal receptors that are activated and inhibited through corresponding synthetic neurotransmitters) or optogenetics (activating and inhibiting neurons and cells with light), to get tantalizing glimpses of a future where brain function can be modified with precision. But for now, the genetic architecture of intelligence remains remarkably stubborn.

Neuroscience Could and Should Inform Policy

Intelligence and socioeconomic factors are deeply intertwined at the neurological level. Intelligence has a heritable component, but gene expression is influenced by environmental factors, making it hard to attribute causal direction in phenotypical traits of intelligence. Variance in intelligence centers around many of the same neurological structures that socioeconomic status (SES) tends to affect. For example: Lower SES is often associated with chronic stress (e.g., financial instability, food insecurity, exposure to violence). Chronic stress leads to dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and increased cortisol levels, which negatively impact brain structures like the hippocampus and prefrontal cortex. These same brain regions are crucial for cognitive function and intelligence, meaning that SES-related stress can influence cognitive abilities, profoundly blurring our understanding. Haier argues that insight into the neuroscience of intelligence will lead to better interventions on early childhood education leading to maximized potentials.

Genetics and the Limits of Malleability

I had a few of my assumptions disquietly rattled by Haier's summation of the state of research. Familiar to me was that genes and their expression are the supreme governors of our individual conditions, but unfamiliar to me was how rigid intelligence is proving to be despite variance in environment. It seems we have fewer broad levers at our disposal than has been impressed upon me by the political conversations of our era. At least, levers besides the basics of nutrition, stress and poverty.

To be honest, all of this probably should not have been too much of a surprise given findings like the ceiling we seem to have hit with longevity. If you have read one of my all time favorite books in the world ever, Behave by Robert Sapolsky, it's even less of a surprise. Physical systems have rules and boundaries, and while there is wiggle room, eventually you have to intervene on the system itself to make changes. There is a difference between realizing potential and enhancing potential.

In case it is still a bit fuzzy (because, let's be honest, heritability can be freaking confusing), we should hash out the finer points of the age-old "genes vs environment" debate.

Imagine you are in a competition. You are going to build a life-sized replica of the Sistine Chapel, heavenly ceiling and all, and will be scored on accuracy. The accuracy score of the replica can represent intelligence scores. The art supplies (clay, marble, sculpting tools, paint, paint brushes) you have represent one's genome. Your creativity represents the environmental forces brought to bear on the material art supplies. As is plain to see, accuracy scores boil down to some combination of the quality and condition of supplies (genes) you possess and your creative ability (environment). If you really want to fill out the analogy, the way your creativity influences how you use the supplies themselves (maybe you modify the brush to result in a better paint stroke or use a supply in an extremely unconventional way), might be something like epigenetics, but we can leave that notion to one side for now.

You might see how, even if you aren't entirely sure that it's a 50/50 split between art supplies and creativity that determines accuracy score, you could form some questions to figure it out:

How well would an IRS tax accountant, with all the creativity of a wooden board, do with all the best art supplies?

How accurate could Picasso be with a single can of gray paint and some dried-out Play-Doh from the 80s?

Are accuracy scores more beholden to one factor or the other?

Does a bad set of art supplies carry a higher risk of inaccuracy than a lack of creativity?

Imagine a genetically gifted individual raised in poverty, without access to formal education, proper nutrition, or social stability. Such a person may fail to fully express their cognitive potential. But—and this is crucial—providing them with optimal conditions does not increase their genetic ceiling; it merely allows them to approach it. The inverse is also true: placing an individual with modest genetic endowment into ideal conditions will not produce brilliance. This asymmetry reveals a troubling truth—public policy can mitigate cognitive underdevelopment, but it cannot manufacture genius. Tabula rasa and similar theories attempt to achieve neurobiological Alchemy.

With a pile of shitty art supplies, Picasso may approach the high accuracy scores more successfully than the uninspired IRS accountant would (this would analogize to an improvement in environment), but the set of supplies is assymetrically restrictive on accuracy score.

We are all aware that our body's parameters are foisted upon us: your muscle size, physical health and metabolism have individually limited ranges. Do all the bicep curls you want, but the upper limit of your arm muscles' size is determined not by how many you do, but by how muscular your parents' and grandparents' biceps were. Mental health is an abstraction of the physical, so too does it come with limits: we all have our genetic predispositions. It is no coincidence that the explosion of effective and dynamic interventions for entrenched mental health problems were not during remedial Freudian or Jungian psychoanalytic and psychodynamic theories' peak in popularity, but instead at the advent of systemic physical interventions (caveat: therapy can be effective, but therapy is also a path to changing physical processes in the brain).

These facts have serious implications for the way we think about educational spending, social welfare, and upward mobility. If intelligence is predominantly genetic, then our capacity to create a society of uniformly high performers rich in ability is fundamentally constrained. To nip both the respective typical conservative and typical liberal arguments in the bud: it is not merely a question of will or program investment. It is a question of biology.

Public Policy Implications

I tend to be in favor of building and preserving common-sense public goods, utilizing public intervention when we can make a good case for it. Providing pathways for education is a no-brainer, but I was under the impression that the social reactionary arguments to heavy genetic influence on intelligence had it mostly correct: I thought, blithely, that sending my kids to good schools will dictate their cleverness and success. To be honest, knowing how much I struggled in school (for a number of reasons, I spectacularly failed out of my first high school and barely made it through university), it is a deeply disconcerting notion that those stages of my own life might be in some sense chained to my predispositions. Quite often wonder: just how tightly coupled were those events? What factor would have changed my trajectory, if any? Naturally, a question like that leads me to worry about what I might pass on to my own children.

In the middle of this book I had a small crisis: Do many of our cherished social policies rest on fiction? Even if we can intervene on intelligence in the future, what is the point of good education systems now if we can never break the upper limit of our custom, genetically-configured intelligence? In other words, if the best we can hope for is that by going to school you meet your full genetically-bound potential, but not exceed or improve on it, then why dump public money into a school system that won't ever do what it sets out to do: fundamentally increase ability? Are we doing the equivalent of sending everyone to the NFL combine and expecting Tom Bradys across the board?

While I will admit I hadn’t explicitly considered the relationship between school systems, neurobiology, and outcomes, my cursory notions now seem, at best, naive. I am not sure I would have called myself a subscriber to "Blank Slate" Theories (Steven Pinker argued compellingly against it and related social theories, explaining some of the social campaigns in certain fields of research), but I certainly thought the split between genes and environment was closer to 50/50 than the roughly 80/20 split the data suggests it to be. I thought overhauling school systems, a not-so-uncommon political idea with various attempts at execution over the years, was a legitimate, effective, and simple solution (at least, relative to biological solutions) for getting everyone into a higher economic class, potentiating success, and encouraging individual achievement.

Let me be clear: quite obviously, schooling and other early childhood development programs offer far more than just presumed intelligence gains. They benefit participants by providing opportunities for socialization, athletics, nutrition (in some cases, very, very sadly, the best a child will get all week), novel experiences, and relief for overextended parents, among other things. It's a long list that justifies itself many times over. And, even if good early childhood development platforms simply allow realization instead of revolution of ability, that's another boon to add to the list. Fulfillment of potential is a worthy goal.

To touch on my own political views: I think society has a moral imperative to provide resources for those who, through no fault of their own (because who in the flying f**k chooses to be disadvantaged by poverty or other debilitating hardships and conditions?) to provide platforms and opportunities for increases in socioeconomic status, leaving as few of our fellow humans behind as we can. Note: when I said "society has a moral imperative", by "society" I specifically mean government and the public institutions it presides over; there is no other entity to perform this function at the margins. The state protects and serves those that markets don't.

None of this is mutually exclusive needing skills, merit, and hard work to discover the next miracle drug or cure for cancer — it simply shows we’ve established clear pathways and systems (school, access to healthcare, good employment, and income) that afford people a better life. We should give everyone every opportunity to intervene on their own circumstances. It's, at base, a Rawlsian framework, and yes, I am aware that it's easier to hold 10,000 feet high moral views and much harder to form legislation and policy around them.

Better understanding leads to better interventions leads to better policy leads to better lives and better human flourishing. It's a straightforward formula.

Public Policy Dilemmas

Neurobiology offers a promising path to intervene on certain conditions that contribute to socioeconomic status, with intelligence being one among many. Look no further than SSRIs or Adderall or, the newest miracle drug, semaglutide (Ozempic), to see what can be provisionally achieved. What used to be stigmatized, misdiagnosed, with sequelae misattributed to all sorts of false proximate causes (most of them moral or philosphical "shortcomings" instead of medical or physical prognoses) is now understood and, better yet, treated by these interventions.

But critics hold that neurobiology, a somewhat fledgling field, which deals in hard-to-understand genes, their complex expressions and probabilites of outcomes, is not the right thing to concentrate on right now—it doesn't yet scale to public policy. As mentioned earlier, there is the gargantuan problem of an intelligence and SES confound. Couple that with how much more we have to understand about the neurobiological underpinnings of intelligence and the years we have ahead of us trying to tease it apart (at our current snail’s pace), and it feels daunting. So, even with overwhelming experimental data suggesting the genome’s primacy over environment, poverty reduction remains the procedurally superior intervention: it's just simply more practical in many people's eyes. I certainly see their point.

The Discomfort of Morality

It's not hard to see the risks to embracing this research path. History has witnessed innumerable appalling and morally corrupt abuses of intelligence research—eugenics, forced sterilizations, and systemic discrimination against perceived "inferior" populations. We must disentangle the truth of intelligence from the crimes committed in its name.

While, in innumerable ways, our world is a better iteration of the world of a few short decades ago (read one of my favorite books ever on it if you don't believe me), just skimming the current headlines and witnessing the idiocracy, dumb political beliefs and alarming new political movements might give you cause for doubting that we can behave responsibly with knowledge on biological factors of intelligence. Or, you might even distrust our ability to use whatever comes of such knowledge effectively. I mean, we're still trying to convince people about basic, evidence-based findings surrounding things like vaccines, the earth being round, or depression being a much more complicated problem than a simple personality trait like laziness, for crying out loud. Even modern intellectuals and researchers are mired in controversy surrounding intelligence-just google Charles Murray or E.O. Wilson. Although, as an aside: people frequently misrepresent many of these researchers’ views, and the current state of research, as summarized by Haier, suggests we should lower the pitchforks, suppress our gag reflex, and have a real conversation about the data.

And if all of doesn't give you pause... we can talk about the elephant in the room: the current administration has made anti-intellectualism and scoffing at expert, scientific opinion a calling card. They have mangled, misrepresented and bastardized the specifics of certain research projects funded by the government in order to make them sound so ridiculous as to deride science in general or use it to shove politics down our throats (although liberal politics rendered their own problems in academia). The admin has pulled valuable funding from the NIH and other institutes, some of the most productive and prestigious scientific institutes in the world, seemingly unaware or uncaring of the fact that government funding is responsible for some of the best scientific projects and discoveries in our lifetimes. The sheer irresponsibility with injecting this brand of politics into 21st century science is enough to make you want to pack up all your shit, buy a boat, scream the lyrics to N.W.A.'s most enduring hit for dramatic emphasis, and risk death attempting to join the Sentinal Islanders in their isolation.

All of the above is to say: the hesitance is, if you ask me, probably one of the most understandable things, well, ever. We live in a world that platforms some breathtakingly stupid ideas and unbelievably stupid people.

Even so, I would argue there is good reason to hope we might be alright. Many, many more ethical bodies, laws, regulations, guiding medical boards, science organizations, and even the deep knowledge we have built (which directly refutes the morally corrupt claims made in times past) won't allow us to retreat backwards unless all these relevant parties and organizations somehow develop amnesia, forget their purpose and toss our moral progress to the winds. even if it gets lost in the smoke and mirrors of daily headlines, Enlightenment, I am hoping and betting, is here to stay. It's not a guarantee that there won't be some crackpot who misrepresents the data to make invidious arguments, but in my view:

• That already happens today, both with genetics and in other arenas. Think race and crime statistics used to justify all manner of modern bogus theories, or different prejudices against mental health, sexual orientation and trans people being groomers, etc. We certainly don't want more of it, but it wouldn't really introduce a new risk.
• It seems a safe bet that good morals and science will continue to have purchase and win out as they have over the last couple hundred years.

The key word in bullet point 2 is "continue": good morals and science are what got us to this more ethical stage of flourishing in the 21st century in the first place. Better morals have better purchase and life is just plain better than it was even 50 years ago, despite our current struggles. Call me a naive optimist, but I am just following historical trends.

As uncomfortable as this subject might be, and as conscientiously as we need to traverse this field of research, we should remember: at the end of the day, humans want to improve our circumstances. If we didn't, we'd still be living in caves (here is an awesome read on the mechanisms behind this penchant for improvement) and it is, quite objectively, a good thing we are not still in caves. Everyone would take a pill to magically improve their circumstances that inform wellbeing, with intelligently navigating life being one such informant. We have been bending the universe, securing flourishing for ourselves and our descendents for hundreds of thousands of years. This yearning for knowledge and the repudiation of stagnancy is at the basis of, well, pretty much all scientific endeavor, the genesis of which is the Englightenment. The benefit of SSRIs, cancer treatements and other physical and societal interventions are, to a one, borne of the will to improve our unconsenting participation in genetic and environmental lotteries.

The overarching moral argument here is simple: intervene if we can.

We do not hesitate to treat depression with SSRIs, cancer with chemotherapy, or diabetes with insulin. And yet, when it comes to intelligence—a variable as biologically grounded as any other—our moral inhibitions remain paralyzing. But the logic is no different: if cognitive capacity profoundly influences life outcomes, then improving cognitive capacity—whether through genetic engineering, the proximate environmental causes of expression or other neurobiological intervention—is as morally urgent as treating any other condition that diminishes human flourishing. The question is not only one dealing with human potential and flourishing: it is one dealing with suffering. Suffering only absolves itself of necessity with knowledge and progress. Poverty, educational failure, chronic unemployment—these are not merely social failings but poorly understood neurobiological ones. Read that sentence again if you attribute failings mainly to simplistic phenomena like laziness or individual will. As I have laid out before, once neurobiology is invited to stand under the eaves of morality and philosophy, it should profoundly shift our ontological foundations.

We should want to toss out the chaotic, primordial genetic soup that birthed our species; its expiration date has passed. Instead, let us adjust this soup's recipe to an impactful genetic broth with maximal potential.