What If Human Intelligence Isn’t One Thing, but Three?

TL;DR

We propose that human brain evolution was shaped by three tempos of environmental uncertainty, with strong fossil support for behavioral flexibility under uncertainty (H1), plausible but untested support for timing/discrimination (H2), and speculative behavioral support for recovery pacing (H3), presented as a transparent, living research program rather than a finished theory.

A Human–AI Collaboration Exploring the Evolution of Cognitive Tempo

What if human intelligence is not a single, monolithic capacity but a three-tempo system — a cognitive engine shaped by distinct classes of environmental uncertainty?

That question has guided an unusual collaboration over the past year — a partnership between me, a transformation leader and lifelong student of entropy, and a suite of AI systems working as analytical companions. Together, we’ve been testing an idea:

H1, H2, and H3 represent three evolutionary “tempos” of cognition — three adaptive strategies shaped by the rhythms of danger, opportunity, and recovery in deep time.

One of them appears strongly supported by the fossil and climate record. One is plausible but unproven. One is purely speculative at this stage.

This article is our progress report, including what has survived contact with data, what hasn’t, and how we’re keeping ourselves scientifically honest.

What This Framework Is Not

Before we dive in, some guardrails:

• It is not a replacement for existing evolutionary theory; it builds on established paleoanthropology and neuroscience.

• It is not a complete theory of consciousness; it focuses on cognitive tempo and entropy management, not subjective experience.

• It is not claiming certainty; it is explicitly provisional and evidence-sensitive.

• It is not simple environmental determinism; genes, culture, chance, and development all matter.

Think of this as a structured hypothesis space, not a finished monument.

The Three Tempos of Human Cognition

“Tempo” here is not poetic fluff. It refers to the timescale of a decision loop — how fast a cognitive control system senses, decides, and acts.

H1 — Flexibility Under Uncertainty (Seasons to Years)

Strategic switching when the world is unpredictable.

• Should we migrate or stay?

• Should we switch from hunting to foraging?

• Do we need a new strategy after three failed hunts?

H1 covers multi-season decisions — the tempo of planning, scenario modeling, and adaptive flexibility.

H2 — Fast Discrimination Under Information Pressure (Seconds to Minutes)

Rapid cue integration when timing matters.

• Is that rustle prey or predator?

• Who moves first in a tense social moment?

• When exactly do I release a spear or throw a rock?

H2 governs short-loop timing decisions, where milliseconds or seconds change survival odds.

H3 — Recovery and Pacing (Hours to Days)

When to push, when to rest, and how hard is too hard?

• After yesterday’s exhausting hunt, how aggressively should we push today?

• How much risk can we tolerate on low calories?

• Do we conserve energy for a predicted hard season?

H3 controls effort allocation after exertion — a tempo of managing energy and avoiding catastrophic overreach.

Taken together, these three tempos describe not just “thinking” in the abstract, but the ancient speed-gradient of survival.

Testing the Theory Against the Fossil Record

If this framework reflects how evolution actually shaped us, we should see traces of it in the hardest evidence we have:

• paleoclimate data

• hominin fossil neuroanatomy

• survival vs. extinction patterns

So we tested H1/H2/H3 against the fossil record. Here’s what we found.

H1: Strongly Supported by Diverse Evidence

1. Climate Variability Jumped Dramatically

Paleo-data reveal three major pulses of environmental instability:

• ~2.8 million years ago

• ~1.8 million years ago

• ~275–60 thousand years ago

During these windows, climate oscillations intensified — more frequent and more extreme swings in temperature, rainfall, and habitat structure.

These were not gentle ripples. They were fat-tailed swings in the environment.

2. The Brain’s Strategic Systems Expanded Disproportionately

Across the hominin lineage, we see:

• Prefrontal cortex:

• ~58cc → ~250cc

• Subcortical systems (brainstem, basal ganglia, etc.):

• ~135cc → ~317cc

• Total brain volume:

• ~438cc → ~1,350cc

In relative terms:

• Strategic planning systems expanded ~4.2×

• Basic monitoring systems expanded ~2.4×

• Total brain expanded ~3.1×

By the time of Homo sapiens, the prefrontal cortex increased from about 13.2% to 18.5% of total volume — a ~40% proportional increase in the very tissue that supports planning, abstraction, and strategic reconfiguration.

This is exactly what H1 predicts:

When environmental entropy rises, evolution invests in flexibility and planning, not just more reflex.

3. The Paranthropus Test Case

Paranthropus lived alongside early Homo during the early phases of climate variability. Faced with an increasingly unpredictable environment, Paranthropus bet on dietary specialization:

• massive jaws

• enormous molars

• robust chewing apparatus for hard, fibrous foods

Their brains remained relatively small, and their prefrontal areas did not show the same strategic explosion.

As climate instability intensified, Paranthropus went extinct (~1.2 Ma).

Homo, with its heavier investment in flexible, strategic cortex, survived and diversified.

This is the H1 story in miniature: under rising uncertainty, specialists die, generalists flex.

H2: Plausible, Mechanistically Sound, but Not Fossil-Testable

The fossil record shows no meaningful proportional change in secondary sensory association areas (~17–18% of total volume across major transitions).

At face value, that weakens H2.

But H2 was never primarily about “more tissue”; it was about better wiring:

• faster conduction via myelination

• stronger long-range white matter tracts (fronto-parietal networks)

• cerebellar prediction loops for timing and coordination

• improved synchronization between regions

None of this fossilizes.

So the fossil record is silent, not refuting. H2 remains:

A low-to-moderate confidence hypothesis — mechanistically plausible, but awaiting tests in:

• diffusion MRI (DTI)

• timing tasks under uncertainty

• comparative studies in variable vs. stable ecologies.

  
  

We don’t treat H2 as “true.” We treat it as interesting and testable.

H3: A Behavioral–Cultural Hypothesis, Not an Anatomical One

Here the fossils are actively unhelpful in an interesting way.

The subcortical systems most associated with autonomic regulation and survival — brainstem, hypothalamus, etc. — shrank proportionally as cortex expanded.

So if we had predicted that H3 required larger brainstem/hypothalamic volume, the data would contradict us.

But H3 was never really about new hardware. It is about:

• meta-control policies: when to stop, when to push

• group pacing norms: how a band allocates effort across days and seasons

• cultural buffers: rituals, rest days, seasonal cycles

• intertemporal choices: “rest now vs. push for a big payoff”

All of that can emerge from existing hardware under new control laws, especially via expanded prefrontal systems and cultural evolution.

So H3 today is:

A speculative behavioral and cultural hypothesis, motivated by thermodynamics and everyday observation, but in need of:

• ethnographic testing

• physiological pacing studies

• endurance/effort experiments in uncertain environments.

We make no claim that H3 has anatomical support. It doesn’t.

Epistemic Status: Where Each Hypothesis Currently Stands

We want the asymmetry in evidence to be unmistakable.

Confidence Bars (visual intuition)

H1 — Behavioral Flexibility Under Uncertainty(High confidence: ~75–85%)███████████████████████████Fossil support: STRONG ✓Status: Validated core component

H2 — Timing & Discrimination Under Information Pressure(Low–Moderate confidence: ~25–40%)██████████░░░░░░░░░░░░░░░░Fossil support: NONE (expected; lives in connectivity)Status: Plausible, requires connectivity testing

H3 — Recovery Pacing Under Clustered Stress(Low confidence: ~15–30%)██████░░░░░░░░░░░░░░░░░░░Fossil support: NONE (behavioral/cultural)Status: Speculative hypothesis

Confidence Table (structured summary)

We keep the triad because it’s a coherent way to organize three different control problems. But we do not pretend they are equally confirmed.

Integrity Check: Avoiding the “Vaseline on the Lens” Trick

A recent Big Think article described a depressing pattern in some modern research:

• cherry-picking data

• avoiding the strongest available tests

• overselling results as “revolutionary”

• shifting definitions after evidence contradicts you

• never specifying what would falsify your idea

We didn’t want to become a case study in that article.

So we asked explicitly:

Are we just moving the goalposts to protect a pretty framework?

To guard against that, we:

• Made H1 the only strongly supported component.

• Explicitly downgraded H2 and H3.

• Acknowledged where fossils don’t support us.

• Separated abstract principles (entropy and tempo) from specific implementations (brain regions, wiring, culture).

• Wrote down concrete falsification criteria for each hypothesis.

Scientific integrity is not avoiding being wrong. It’s being auditable about how you might be wrong.

How We Could Be Wrong: Falsification Criteria

If your theory can’t be wrong, it can’t be scientific. Here’s how ours could be.

H1 would be in serious trouble if:

• Prefrontal expansion of similar magnitude appears in species that did not face high climate variability.

• Genetic evidence suggests prefrontal changes were mostly neutral drift, not adaptive response.

• Cross-species comparisons show no relationship between environmental uncertainty and strategic planning systems.

• A simpler explanatory framework (e.g., only social group size, only diet) accounts for the same patterns more parsimoniously.

H2 would be weakened or abandoned if:

• Diffusion MRI (DTI) shows no link between uncertainty exposure (ancestral or present) and fronto-parietal or cerebellar connectivity.

• Timing/discrimination tasks reveal no systematic differences in populations with different ancestral ecological volatility.

• Comparative work finds animals in highly variable environments do not show any enhanced timing/discrimination circuitry.

• Multiple independent studies return null results on all fronts.

H3 would be weakened or abandoned if:

• Ethnographic data shows no relationship between environmental volatility and recovery/pacing norms (e.g., same pacing strategies in extremely stable and extremely unstable environments).

• Experimental manipulation of pacing vs. all-out effort in uncertain endurance contexts shows no performance advantage to structured recovery.

• Physiological monitoring contradicts the pacing story (e.g., organisms in variable environments do just as well with unstructured effort).

• Cultural recovery practices appear essentially random with respect to ecological structure.

And here’s the important part:

When some of these falsifiers inevitably materialize — as they likely will for at least parts of this framework — we will document what we learned and revise or abandon accordingly.

What Comes Next: A Research Program, Not a Proclamation

This is not a finished theory being sold to you. It’s a research program we’re inviting others to stress-test.

1. Fossil Neuroanatomy (H1 refinement)

Continue refining volumetric estimates and climate alignment across more hominin species.

2. Connectivity & Timing Studies (H2 testing)

• DTI/structural connectivity in humans with different ecological histories

• Behavioral timing tasks under uncertainty

• Cross-species comparisons in variable vs. stable environments

3. Ethnographic & Behavioral Work (H3 testing)

• Cross-cultural analysis of pacing and recovery norms

• Field studies in foragers and subsistence populations

• Lab studies on endurance, pacing, and clustered stress

4. Systems Applications

• Using the three-tempo framework to design organizational workflows

• Embedding it into the Entropy Engine for adaptive system control

• Exploring how modern environments overload H1, H2, or H3

Some of this work will support the model. Some will contradict it. That’s the point.

Join the Investigation

We need collaborators .

If you’re a paleontologist or evolutionary biologist:

• Challenge our fossil interpretations and climate alignments.

• Suggest species/datasets we’ve overlooked.

• Offer alternative stories that explain the same data.

If you’re a neuroscientist:

• Help design connectivity and timing experiments to test H2.

• Point out where our neuroanatomical assumptions are naive or incomplete.

• Suggest better ways to measure “tempo” in living brains.

If you’re an anthropologist or ethnographer:

• Share data on cultural recovery/pacing practices across populations.

• Help us avoid romanticized or simplistic assumptions about foragers.

• Identify real-world rituals and norms that might instantiate H3 — or contradict it.

If you’re a statistician or methodologist:

• Audit our confidence intervals and reasoning.

• Propose stronger analyses or model comparisons.

• Help us detect and avoid “pretty story” bias.

If you’re simply curious:

• Ask hard questions that force us to clarify our thinking.

• Point out where we’re unclear, overclaiming, or hand-wavy.

• Share this with people who might be able to stress-test it.

Science grows through conversation, critique, and community — not proclamation.

Closing: Science as a Living Practice, Not a Performance

We set out to ask whether humans are, at root, three-tempo thinkers — creatures built to react quickly, reflect slowly, and recover strategically in a world that refused to sit still.

The journey has already forced us to:

• demote two-thirds of our initial triad to speculative status,

• accept that some beautiful symmetries might not survive,

• and embrace the fact that a good framework must invite its own revision.

That’s not a bug; it’s the essence of honest inquiry.

This framework will evolve as evidence demands. Parts of it will fail. New versions will emerge. The point is not to protect the model — it’s to learn from how it breaks.

Thank you for walking this path with us.

— Henry

Document Status & Future Updates

• Status: Living progress report, Version 1.0 (November 2025)

• Planned Update Milestones (tentative):

• v1.1 (Q1 2026): Incorporate first round of expert feedback and critiques.

• v2.0 (Q2–Q3 2026): Integrate initial connectivity/timing results relevant to H2.

• v3.0 (beyond): Summarize ethnographic/behavioral findings relevant to H3.

Each new version will:

• update confidence levels as evidence accumulates,

• document failed predictions and revisions,

• and provide references to any peer-reviewed publications that emerge.

Funding & Conflicts of Interest

This work is currently self-funded. There are no institutional or commercial sponsors, and no financial conflicts of interest are known to the author. The collaborating AI systems are tools, not stakeholders.