If consciousness is the stage, free will is the question of who's writing the script. Do we choose our thoughts and actions, or are they determined by causes — genes, brain states, prior experiences — over which we have no ultimate control?
Two lines of evidence — twin studies and neuroscience — suggest that the answer is more unsettling than most of us want to believe.
Part I: The Genetics of "Choice"
The Jim Twins (1979)
Jim Lewis and Jim Springer were identical twins born in 1940 in Ohio, separated at three weeks old and adopted by different families 40 miles apart. They met for the first time on February 9, 1979, at age 39.
Their lives had been running on eerily parallel tracks:
- Both named James by their adoptive parents; both called Jim
- Both had childhood dogs named Toy
- Both married women named Linda, divorced, then married women named Betty
- Both named their sons James Alan/Allan
- Both worked in law enforcement and security
- Both drove Chevrolets, smoked Salem cigarettes
- Both vacationed at the same beach in St. Petersburg, Florida
- Both suffered tension headaches starting at age 18
- Both were nail biters who gained 10 pounds at the same point in life
Their medical histories and brain-wave patterns were nearly identical. The question isn't whether genetics influenced their lives — it's whether "choice" played any meaningful role at all.
The Nazi and the Jew: Oskar & Jack (1933–2015)
If the Jim Twins shared similar Ohio environments, Oskar Stöhr and Jack Yufe destroy that objection. Born in Trinidad in 1933, separated at six months:
- Jack: raised Jewish in the Caribbean by his father
- Oskar: raised Catholic in Nazi Germany by his grandmother; joined the Hitler Youth
Thomas Bouchard called them the twins with "the greatest differences in background I've ever seen." Yet when they met in 1979:
- Both read books back-to-front
- Both wrapped rubber bands around their wrists
- Both taped pens for a better grip
- Both loved butter and spicy foods
- Both enjoyed sneezing loudly in public to startle people
- Both flushed the toilet before using it
- Both had the same gait and wore similar glasses
Environment shaped their ideologies. But something deeper — something encoded in their shared DNA — shaped their behavioral quirks, preferences, and habits. These weren't "choices" in any meaningful sense.
MISTRA: The Minnesota Study (1979–1999)
The Jim Twins and Oskar/Jack were part of the Minnesota Study of Twins Reared Apart, led by psychologist Thomas Bouchard. Over 20 years, the study examined 137 twin pairs (81 identical, 56 fraternal).
Published in Science in 1990, the findings were striking:
"On multiple measures of personality and temperament, occupational and leisure-time interests, and social attitudes, monozygotic twins reared apart are about as similar as monozygotic twins reared together." — Bouchard et al., Science, 1990
The implication: growing up in the same household doesn't make identical twins any more similar than growing up in different households. Shared environment contributes far less than genetics to who we become.
Criticisms: Many "separated" twins were placed in similar socioeconomic environments. The study omitted some control-group data. A 2022 reevaluation argued IQ heritability estimates may be inflated. Important caveats — but the pattern across dozens of twin pairs is hard to dismiss.
Twin Strangers & Doppelgängers
If identical twins living parallel lives can be explained by shared DNA, what do we make of unrelated people who look nearly identical?
The "Twin Strangers" project and viral social media have documented dozens of cases of unrelated individuals — from different countries, different ethnicities, different continents — who are visually indistinguishable. In some cases, DNA tests confirm no familial relationship whatsoever.
The science behind doppelgängers:
- Human faces are constructed from a finite set of genetic variables — eye spacing, nose bridge width, jaw angle, lip shape. With ~8 billion people and a limited number of configurations, repeats are statistically inevitable.
- A 2022 study in Cell Reports found that unrelated lookalikes share significant genetic variants — not from common ancestry, but from convergent genetic combinations producing the same facial geometry independently.
- The lookalikes also shared behavioral and lifestyle similarities — similar BMI, smoking habits, and education levels — suggesting that shared genetic variants influence more than just appearance.
Doppelgängers extend the Jim Twins argument in a new direction. The twins prove that shared DNA produces shared lives. Doppelgängers suggest that even unrelated people, when dealt similar genetic hands by chance, converge toward similar outcomes. The genome is not a unique script for each individual — it is a finite alphabet that can only spell so many words. Your face, your body, your behavioral tendencies may not be as unique as you feel they are.
In the context of simulation theory: doppelgängers look suspiciously like asset reuse — a rendering engine recycling character models to conserve resources.
Part II: Your Brain Decides Before You Do
Twin studies show genetics constrains choices. Neuroscience goes further: the brain appears to make decisions before conscious awareness of "deciding" even begins.
The Libet Experiment (1983)
Physiologist Benjamin Libet asked subjects to flick their wrist whenever they felt like it, while EEG electrodes recorded their brain activity. Subjects watched a precision clock and reported the exact moment they felt the urge to move.
The Readiness Potential begins — the brain's motor cortex starts preparing the movement.
The subject consciously reports the urge to move. They believe this is when they "decide."
The wrist flicks.
The brain began preparing the action 350 ms before the subject was aware of deciding. Conscious will arrived after the process was already underway.
Libet himself was nuanced: he proposed a "veto" power — consciousness might not initiate actions, but it could block them in the final 200ms. Free will as a "free won't."
Soon et al. — 10 Seconds (2008)
At the Max Planck Institute, researchers used fMRI to watch subjects freely choose to press a button with their left or right hand. By reading activity in the frontopolar cortex and precuneus, they could predict the choice up to 10 seconds before the subject reported deciding.
"The outcome of a decision can be encoded in brain activity of prefrontal and parietal cortex up to 10 seconds before it enters awareness."
— Soon et al., Nature Neuroscience, 2008
Accuracy was ~60% (chance: 50%) — modest but significant. The task was simple (left hand vs. right hand), not a life decision. But the principle holds: neural "decisions" precede conscious awareness by seconds, not milliseconds.
Try it yourself → Our interactive Button Experiment lets you press Left or Right 20 times while a simple algorithm tries to predict your "free" choices.
Part III: The Philosophical Landscape
Hard Determinism
Every event, including every human decision, is the inevitable result of prior causes. Your genes, your upbringing, the state of your neurons one millisecond ago — these fully determine what you "choose" next. Free will is an illusion.
Robert Sapolsky (Determined, 2023) argues this position with biological rigor: trace any behavior backward through seconds, hours, years, back to the womb, back to your ancestors, and at no point do you find a gap where an uncaused "free choice" enters. The chain of causation is unbroken.
Sam Harris (Free Will, 2012) makes a complementary argument from neuroscience and introspection: "Thoughts and intentions emerge from background causes of which we are unaware and over which we exert no conscious control."
Compatibilism ("Soft Determinism")
The most popular position among philosophers (accepted by ~59% in a 2020 survey). Compatibilists agree the universe may be deterministic, but argue free will is compatible with determinism — we just need to define "free" correctly.
A free choice isn't one that's uncaused; it's one that flows from your own desires, beliefs, and character, rather than from external coercion. You're free when you do what you want, even if what you want is determined.
Daniel Dennett and Harry Frankfurt champion this view. Frankfurt's key insight: free will doesn't require the ability to do otherwise. If you would have chosen the same thing anyway, the deterministic causal chain doesn't remove your freedom.
Libertarian Free Will
(Not political libertarianism.) This position holds that determinism is false — that at the moment of decision, we are genuine causal agents who could truly have chosen differently. Quantum indeterminacy is sometimes invoked as a mechanism, though critics note that randomness is not the same as freedom.
Part IV: Superdeterminism
Hard determinism says your choices are determined by prior causes. Superdeterminism says everything is — including the experiments physicists design to test whether determinism is true. It is the most extreme, most controversial, and most philosophically devastating position in the entire free will debate.
Bell's Theorem and Its Loophole
In 1964, physicist John Bell proved a theorem that shook the foundations of physics. He showed that if hidden variables exist beneath quantum mechanics — if particles have definite properties before measurement — then the universe must be nonlocal: information or influence must travel faster than light.
Experiments have repeatedly confirmed that Bell's inequalities are violated. Most physicists take this as proof that the universe is either:
- Nonlocal: particles influence each other instantaneously across any distance (the mainstream view)
- Non-real: particles don't have definite properties until measured (Copenhagen interpretation)
But Bell's proof rests on a critical assumption: measurement independence — the idea that the experimenter's choice of what to measure is not correlated with the hidden variables of the particle being measured. The experimenter is free to choose any measurement setting. Their choice is independent of the system.
What if that assumption is wrong?
The Superdeterminist Position
Superdeterminism says measurement independence is false. The experimenter's "choice" of measurement setting and the particle's hidden variables are correlated — because both were determined by the initial conditions of the universe at the Big Bang.
In this view:
- The universe is entirely local — no faster-than-light influences, no "spooky action at a distance"
- The universe is entirely deterministic — every event, from particle spin to human thought, follows from the initial conditions
- The experimenter never had a free choice — the "decision" to measure spin along axis X rather than axis Y was determined at the Big Bang, and is correlated with the particle's properties because both emerged from the same initial state
- Quantum mechanics is not fundamental — it is a statistical approximation of a deeper, deterministic theory
The correlations aren't a conspiracy. They're a consequence of everything sharing a common origin. Every particle, every neuron, every "choice" traces back to the same initial conditions 13.8 billion years ago. Of course they're correlated.
Who Takes It Seriously
Superdeterminism is a minority position, but its advocates are not fringe figures:
- Gerard 't Hooft (Nobel Prize in Physics, 1999): has argued since the 1980s that quantum mechanics emerges from a deeper deterministic theory, and that the measurement independence assumption is unjustified. He discussed this directly with Bell himself.
- Sabine Hossenfelder (Frankfurt Institute for Advanced Studies): has published peer-reviewed work arguing superdeterminism is "the forgotten solution" to quantum foundations, and has proposed specific superdeterministic models. In a 2020 paper in Frontiers in Physics, she and co-author Tim Palmer argued for "Rethinking Superdeterminism."
- Tim Palmer (Oxford, Royal Society Fellow): has developed "Invariant Set Theory," a superdeterministic framework based on fractal geometry in state space.
The Devastating Criticism
Superdeterminism has a formidable opponent: nearly everyone else. The objections are severe:
- It destroys science. Physicist Anton Zeilinger (Nobel Prize, 2022): "We always implicitly assume the freedom of the experimentalist — this fundamental assumption is essential to doing science." If the experimenter's choices are correlated with what they're measuring, no experiment can be trusted. Every result could be an artifact of hidden correlations rather than a genuine property of nature.
- It's unfalsifiable. The correlations can be postulated to exist since the Big Bang, making the theory impossible to test. Any experimental result is consistent with superdeterminism, because the experiment itself was determined.
- It's conspiratorial. Critics argue it requires implausible "cosmic conspiracies" — that the universe arranged itself 13.8 billion years ago so that every future measurement would be correlated with its target in exactly the right way to mimic quantum mechanics.
Hossenfelder counters that "conspiracy" is the wrong frame. The correlations aren't arranged for anything — they're simply a consequence of deterministic evolution from shared initial conditions. We don't call it a "conspiracy" when the positions of planets are correlated with the initial state of the solar nebula.
Why It Belongs Here
Superdeterminism is the position where free will, quantum mechanics, and cosmology collide:
- It eliminates free will entirely — more radically than any other position. Hard determinism says your choices are caused by prior events. Superdeterminism says even your ability to test whether choices are caused is itself caused. There is no escape hatch, no veto, no exception.
- It resolves the quantum measurement problem — if there's no free choice in measurement, there's no measurement problem. The wave function doesn't "collapse" because the outcome was determined from the start.
- It preserves locality — no faster-than-light influences, no entanglement paradoxes. The universe is local and deterministic, as Einstein always believed.
- It connects to the block universe — if all times exist simultaneously, and the initial conditions determine everything, then the block is not just static but maximally correlated. Every part of spacetime is entangled with every other part through shared origin.
"The question is not whether God plays dice. The question is whether God had any choice in creating the universe." — attributed to Einstein (paraphrased)
If superdeterminism is true, the answer is no. And neither did you.
Why It Matters
The free will debate isn't abstract. It touches:
- Criminal justice: if a murderer's actions were determined by biology and circumstance, what does "moral responsibility" mean? Should punishment be retributive, or purely rehabilitative?
- Personal identity: if your preferences, personality, and decisions are genetically loaded, who are "you"?
- Compassion: both Harris and Sapolsky argue that abandoning the free will illusion leads to more compassion, not less — you stop blaming people for being products of causes they didn't choose