Quantum experiments may soon test the limits of human free will

Do we have free will? Quantum physicists are preparing to find out

New equations may soon settle a long-standing debate with far-reaching consequences

The question of whether human beings truly have free will — or are merely following a script written by the laws of physics — may finally be tested in the lab, thanks to a breakthrough in quantum theory. A team of researchers has developed new mathematical tools that could enable experiments to directly probe whether our choices are predetermined, partially free, or fully autonomous.

“If we want to understand the universe, opinions don’t matter. Only experiments and mathematics do,” says physicist Adán Cabello of the University of Seville, who co-authored the new study alongside Ravishankar Ramanathan and Carlos Vieira of the University of Hong Kong.

Free will and the quantum puzzle of non-locality

The debate stems from the curious nature of quantum entanglement, in which particles exhibit coordinated behavior across vast distances — a phenomenon known as non-locality. This effect has been validated repeatedly since John Stewart Bell developed a formal way to test it in 1964. Bell’s inequality revealed that if the universe operated solely under local classical laws, certain statistical correlations between particles would be impossible. Yet, experiments have consistently shown those correlations do exist — and violate Bell’s inequality.

One assumption behind these experiments is known as measurement independence — the idea that experimenters, often modeled as “Alice” and “Bob,” are free to choose how they measure entangled particles. But what if this assumption is not entirely valid? Could their choices be partially influenced or predetermined by hidden variables?

Partial free will: a testable hypothesis?

Cabello and his collaborators have formulated new equations similar to Bell’s inequality, but designed to test a subtler proposition: that Alice and Bob might have partial free will. That is, their choices could be free most of the time, but occasionally governed by deterministic laws beyond their control — a concept that echoes theological debates and the foundations of moral philosophy.

“It’s like choosing your breakfast freely every day — except for the rare day when the universe insists you eat cereal,” Cabello says.

Their framework allows for quantifiable testing of such scenarios. Previous attempts to inject human randomness into quantum tests — including one involving 100,000 people playing an online video game — helped reduce the possibility of deterministic loopholes. But this new work goes further by mathematically modeling the range between total free will and total determinism.

Implications for religion, philosophy, and superdeterminism

The potential outcomes of these experiments stretch beyond physics, touching philosophical and even cosmological questions — a direction not unlike recent efforts to explore the universe’s grandest structures, as seen in the discovery of the largest known object in the universe.. Many religious philosophies hinge on the concept of partial free will, reconciling divine omniscience with human accountability. If experiments show even partial free will is incompatible with physical law, this reconciliation could be challenged.

Moreover, the findings may weigh in on interpretations of quantum mechanics such as superdeterminism — the controversial idea that everything, including measurement choices and outcomes, is determined in advance by hidden variables. This theory claims that violations of Bell’s inequality are not evidence of non-locality but simply reflect our lack of access to deeper deterministic laws.

Physicist Tim Palmer of the University of Oxford, a proponent of superdeterminism, sees the new work as crucial: “We either accept that the world is fundamentally indeterministic, or we find a way to explain Bell’s results within a deterministic framework. This research helps test that.”

Quantum computers may assist in the search

Cabello’s team is now designing experiments to bring their theory into the lab. Quantum computers may play a key role in this next phase. Their compact, interconnected architecture makes it impossible to fully isolate all components, naturally raising questions about internal correlations and independence.

“These devices are ideal for testing whether relaxing certain assumptions still allows us to maintain quantum behavior,” explains Ramanathan.

With preparations for testing already underway, physicists are hopeful that we may soon get experimental clarity on one of the most profound questions in science — and perhaps in human existence.

Stay tuned to The Horizons Times for the latest updates on quantum physics, consciousness, and the fundamental nature of reality.