Carl Sagan handed his son a question. Not in a letter or a conversation, but in a book. The Dragons of Eden, published in 1977, asked how the human brain evolved its peculiar intelligence — and it won the Pulitzer Prize doing it. Twenty-five years later, Dorion Sagan and neuroscientist John Skoyles sat down and answered it. What they built is stranger, more unsettling, and in some ways more honest than anything Carl put on the page.
That comparison is unavoidable. Dorion is Carl’s son, and Up from Dragons explicitly positions itself as a sequel to The Dragons of Eden — not a reworking, but, as the authors write in their preface, “a radical revision, setting off again as if for the first time on the intellectual odyssey for which science was not ready when Carl first began his daring expedition.” That’s not false modesty dressed up as ambition. It’s a genuine claim. And when you read it closely, it holds.
What Carl Left Open
Carl Sagan was working in 1977 with the tools available in 1977. The neuroscience was thin. Brain scanning didn’t exist. What he had was evolutionary biology, anthropology, and a gift for synthesis that no science writer since has fully matched. His central argument — that the brain evolved in layers, with older reptilian structures buried under newer mammalian and human ones — was compelling, resonant, and, it turns out, incomplete.
The Dragon of Eden was a metaphor that worked. But a metaphor is not a mechanism. It doesn’t tell you how the leap from smart ape to symbol-using, culture-building, self-aware human actually happened. That’s the gap Skoyles and Dorion Sagan walked into.
The answer they propose is mindware. Not hardware. Not wetware. Mindware — their term for the set of symbol-using, evolution-accelerating mental programs that the neocortex developed to manage increasingly complex social life. The analogy to software is deliberate and illuminating: “Human evolution did not fix our brain’s information processing but instead created reprogrammable neural circuits that could evolve new kinds of intelligence.” You were not born with a fixed operating system. You were born with the capacity to install one.
The Plasticity Argument
The book’s central scientific claim is about neuroplasticity — the brain’s capacity to rewire itself in response to experience, learning, and culture. This was not well understood in Carl’s time. It is understood now, and Skoyles and Sagan make it the load-bearing wall of their entire structure.
The implication is radical. If the brain is genuinely plastic — if it can reprogram itself without waiting for genetic mutation and natural selection — then the standard evolutionary psychology story collapses. Steven Pinker’s genetically hardwired modules, the Swiss Army Knife model of the mind with a dedicated blade for every adaptive problem, takes a serious hit here. Skoyles and Sagan are unambiguous about this: their thesis “deals a devastating blow to currently fashionable concepts of genetically programmed minds.”
Whether you find that convincing depends on what you bring to the question. Publishers Weekly called the arguments “creative” and the evidence “intriguing,” while also noting the controversy the thesis was likely to generate. Some critics pushed back on what they saw as the book’s tendency toward “simplistic materialism” and its failure to account for certain edge cases — possession, dissociation, out-of-body experiences — that don’t fit cleanly into a coherence-based theory of consciousness.
Those are fair objections. But they don’t puncture the core argument. The question isn’t whether the brain is entirely plastic — it isn’t — but whether plasticity is a more important driver of human cognitive evolution than genetic change. Skoyles and Sagan make a credible case that it is.
The Troop Inside Your Head
The part of the book that stays with you longest isn’t the neuroscience. It’s the sociology.
Skoyles and Sagan argue that the key to understanding human consciousness is not the lone brain but the social brain. Before we developed the ability to abstract, to build symbols, to think about people who weren’t in front of us — we were social primates who needed to track relationships, hierarchies, alliances, and betrayals in real time. The prefrontal cortex didn’t evolve to solve equations. It evolved to manage a troop.
They call this “the troop within our heads.” The social structures we navigated on the African savannah didn’t stay outside us. They got internalized. The guilt, shame, pride, and self-consciousness you experience right now are not individual psychological states — they are the residue of social evolution, the echo of a troop you carry with you everywhere. The anterior cingulate cortex acts as what they call a “hidden observer” over everything you do, monitoring your behavior against the social standards the troop installed in you.
This is not a comfortable idea. It means the voice in your head that judges you is not really yours. It’s the troop’s. It evolved to keep you in line. It has been keeping you in line since before you knew what a line was.
Dorion has written about evolution and consciousness across multiple books — including his collaboration with Lynn Margulis on Acquiring Genomes and his own Death/Sex — and this social-brain argument has threads that run through his broader body of work. He is his father’s son in his ability to synthesize across disciplines without losing the thread. But where Carl tended toward the cosmic and the optimistic, Dorion goes somewhere colder. The troop within your head is not there to help you flourish. It’s there to enforce compliance. That distinction matters.
Mindware and the Leap We Can’t Explain
The book poses one of the great embarrassments of cognitive science plainly and doesn’t flinch from it: your brain was evolved for hunter-gatherer life 100,000 years ago. It was not evolved to read, to write code, to do differential calculus, to compose a symphony, or to review a book. And yet here we are, doing all of it with the same hardware that once tracked antelope across a plain.
“No neurologist or paleoanthropologist can explain why your brain, so obviously not evolved to read this, does so, like with so many other non-evolved modern skills, with such great finesse.”
That quote is worth sitting with. Genetically, you are a hunter-gatherer. The gap between what your genes prepared you for and what you are actually doing right now is one of the strangest facts in all of biology. Evolutionary psychology, which tries to explain every modern behavior as an adaptation for the ancestral environment, has no satisfying answer to it. Mindware is Skoyles and Sagan’s answer: the brain built software that runs on top of the genetic hardware, software that can update faster than genes, software that is transmitted culturally rather than biologically.
What the Son Did That the Father Didn’t
Carl Sagan wrote beautifully about what we might become. The Dragons of Eden ends on notes of genuine hope — about the expansion of human intelligence, about the possibility that we might survive our own worst instincts. The dragons were the primitive brain, and the optimism was that we could rise above them.
Dorion doesn’t quite give you that. The troop in your head is not going away. The guilt and shame and self-surveillance installed by millions of years of social primate life are features, not bugs — they are what makes culture possible, and culture is what makes you human. You can’t separate the consciousness from the compliance mechanism. They are the same thing.
That’s a darker read of the human situation than his father offered. It is also, probably, a more accurate one. And there is something that functions like courage in writing it — especially when your father’s book is the one everyone is comparing yours to, and your father’s book won the Pulitzer.
Up from Dragons doesn’t have the narrative sweep of The Dragons of Eden. It is denser, more technical, occasionally frustrating in its ambition to cover too much ground. The Wikipedia review notes the lack of anatomical illustrations as a real limitation, and that’s a fair complaint — a book making arguments about brain architecture probably needs more diagrams than it has. It also doesn’t engage with Leda Cosmides and John Tooby’s evolutionary psychology framework in the depth that framework deserves, which leaves the anti-Pinker argument feeling slightly underargued.
But as an attempt to push past where Carl left off — to take the tools that weren’t available in 1977 and use them to answer the question Carl raised — it is serious, original, and worth the effort. The mindware concept alone is worth the read. The social brain argument will change how you think about the voice in your head.
Some sequels are pale imitations. Some are just different books with a family resemblance. And occasionally, a son takes his father’s map, walks past the edge of it, and draws new territory. This is that kind.
You Might Also Like
- The Selfish Gene by Richard Dawkins — The Book That Unlocked Darwin for Me
- The Ghost in the Machine: Descartes, Dennett, and the Mind That Built the Modern World
- The Extended Phenotype: How Your Genes Build Structures Beyond Your Body
Sources
- Skoyles, John R. and Dorion Sagan. Up from Dragons: The Evolution of Human Intelligence. McGraw-Hill, 2002. Amazon
- Carl Sagan. The Dragons of Eden. Random House, 1977. Wikipedia
- Up from Dragons — Wikipedia. Wikipedia
- Publishers Weekly review. Publishers Weekly
- Goodreads reader reviews. Goodreads
