Fifteen years ago, a young Indian woman named Aditi Sharma made criminal justice history. She had been engaged to be married when she abandoned her fiancé to elope with another man. Six months later, when her ex-partner was found dead, Sharma and her new love, Pravin, were accused of murder. They had, a court in Mumbai heard, poisoned her ex with arsenic.
The evidence was circumstantial and the police needed more to convict, so both suspects were given psychological testing. The first stage was a conventional polygraph, or lie detector test—and the analyst decided Sharma was hiding something. She was then subjected to a new and different kind of probe: a brain electrical oscillation signature test. This is designed to distinguish between different types of memory: on the one hand, conceptual memory, based around recollections of words and language; on the other, experiential memory of actual participation in an event. The first could be passive: you might recall details about Jack the Ripper’s murders, but it would merely reflect the fact that you had studied them at school. The second was, purportedly, active: you were involved.
Left alone in a room with 32 sensors wired to her head, Sharma listened to a series of statements, some about the murder. She was told to remain silent while her brain spoke for her. And when they came, the readouts confirmed the authorities’ suspicions. They became evidence and she was found guilty—and sentenced to life imprisonment.
Sharma was the first person to be convicted primarily on evidence extracted straight from the brain. It was a landmark case for those worried that freedom of thought is under threat, but the truly jaw-dropping moment came next. New findings emerged that implied Sharma’s innocence. Later that year, two others were convicted of the murder—based on evidence also derived from brain electrical oscillation signature tests. Sharma’s conviction was overturned.
As horror stories about technology go, this is extreme. The state peered into an individual’s mind and, using techniques with only a dubious claim to scientific respectability, sought to strip her of her freedom based on what it saw inside. But Susie Alegre, a human-rights barrister at Doughty Street Chambers and author of the recent polemic Freedom to Think, believes it’s just one shocking example of an unfolding human-rights catastrophe. By her account, the powerful now routinely use technology to interfere with our right to mental integrity. From experimental devices that monitor children’s attention spans to the tech billionaires who claim that privacy is no longer a social norm, and whose social media platforms hoover up and sell off our sensitive information, threats to freedom of thought—one of the most sacred and supposedly inviolable rights we have—have become part of everyday life.
Alegre’s perspective is, of course, that of the lawyer. And there are fascinating legal questions running through the heart of this subject. What do instances like the Sharma murder case mean for one’s right not to incriminate oneself? What human-rights tools are available to respond to a new and evolving threat? And when asking what freedom of thought actually means in practice, it may help to look to legal definitions and the language of international human-rights law—but can law give us all the answers we need?
As a starting point, it is worth agreeing that freedom of thought deserves special protection. The philosophers have argued as much for centuries. Spinoza, the great enlightenment free thinker excommunicated from the Dutch Jewish community for his “abominable heresies”, argued that “every man is by indefeasible natural right the master of his own thoughts”. We hear also from John Stuart Mill, Voltaire and others in the course of Alegre’s opening chapters. Freedom of thought is a matter of fundamental liberty and all societies should seek to protect it. We now have international charters and declarations to that effect, not least the UN’s Universal Declaration of Human Rights.
But the wording of the UDHR—which has been translated into binding international treaties on political, social and cultural rights—is indicative of a conceptual problem that runs through the way the law safeguards our inner lives. Its Article 18 states that “everyone has the right to freedom of thought, conscience and religion”, explaining that this includes the freedom “to manifest his religion or belief in teaching, practice, worship and observance.” The next article adds that “everyone has the right to freedom of opinion and expression”.
This phrasing encapsulates the wider issue with the way we protect freedom of thought, which has traditionally been to run it together with freedom of religion and/or freedom of expression. But both of these are very different to freedom of thought. To express something you have to say something, or at least perform an action that amounts to saying something, such as sending a message or a smiley face. Freedom of religion is about belief—but only one kind of belief.
What’s more, there is endless case law on both of these two rights—they have been interpreted and reinterpreted by different judges in different jurisdictions over the generations in an attempt to arrive at a position that society can live with as just. This is not true for freedom of thought, which is only now under wholesale threat. There is an argument that, instead of the dedicated protection such a right deserves, our legal framework has a glaring gap.
Attempting to bridge it, the courts have sometimes turned to privacy law to prevent encroachments on personal integrity. This helps to take us another step in the right direction, but still tends to relate to information that is already in the world outside our heads—and therefore different to the information that swirls around our inner realm. By failing to adjust properly to an evolving threat, our human-rights law is in danger of being overtaken by the challenges of the ubiquitously digital 21st century.
Alegre recognises the urgency of the problem and provides a summary of what the right to free thought must entail. We must be able to keep our thoughts and opinions private; we must be able to form our thoughts and opinions free from manipulation; and we must never be penalised for our thoughts or opinions. Armed with this set of definitions, she mounts an attack on the technology that she sees as one of the greatest threats to freedom of thought in human history.
We learn about BrainCo, a US company that produced headbands with sensors which have been used to scan the brains of Chinese schoolchildren—10,000 of them, between the ages of 10 and 17—to determine their concentration levels, monitored by teachers via an app. Based on electroencephalographic technology, flashing lights on the headbands would also alert teachers to pupils who weren’t focusing hard enough, shaming them into better behaviour.
We also learn about the Spanish company Emotion Research Lab, whose cameras—installed in an electronic billboard—enabled Mexican political strategists to analyse the emotional responses of passers-by seeing campaign messages, reading you while you read them. And Stanford researchers, who claimed they could predict—with scary accuracy—subjects’ political worldviews solely from images of their faces. Sometimes, public outcry can see the most invasive technology pulled from use—but not always.
It would take the average person 76 working days to read the terms and conditions on the websites they browse each year
The book cites evidence confirming the worst things we thought about the tech giants. Everything we do online is monitored and monetised. Through a process known as RTB, or real-time bidding, you are the subject of 164 online auctions a day, your attention bought and sold on the digital advertising exchanges. We do not meaningfully consent to this: it would take the average person 76 working days to read the terms and conditions on the websites they browse each year. But this is not quite the same as violating freedom of thought. To see how the big tech companies do that, we must look to the second of Alegre’s conditions.
The power that tech giants have to manipulate our mental states has been proven. In 2014, Facebook published a study called “Experimental evidence of massive-scale emotional contagion through social networks”. The firm had targeted 700,000 users—without their knowledge—in a two-week experiment, manipulating their newsfeeds to gauge their emotional responses. It found that those shown more negative posts were more likely to then post negative comments themselves. After an outcry from users alarmed at this breach of trust, Facebook apologised; an investigation by the UK Information Commissioner’s Office ultimately went nowhere.
Countless studies since have confirmed the damaging psychological effects of the routine algorithmic manipulation of our newsfeeds, and it is in that context that we see the scale of the threat to free thought. Billions of people have their mental states altered online not because they voluntarily seek out and expose themselves to new information, but because technologies they do not understand—or even know about—shape their experiences in a way that cannot be meaningfully opted out from, or at least not if those people wish to remain functioning members of modern society.
In 2019, the Council of Europe’s Committee of Ministers stated that “fine-grained, sub-conscious and personalised levels of algorithmic persuasion may have significant effects on the cognitive autonomy of individuals and their right to form opinions and take independent decisions.” Alegre is surely right to argue that our human-rights framework must evolve to reckon with this new challenge—and up to a point, it has. India’s Supreme Court has decided that forcible interference with someone’s mental state effectively to extract a statement—especially one of guilt—is unlawful. We have seen progress at the UN and in Europe, where the General Data Protection Regulation (GDPR) framework has been used to challenge the legality of real-time bidding. Chile updated its constitution in 2021 to protect “brain rights”, and continues to experiment with new ways to protect mental integrity.
Naturally, the law cannot do everything here. If it has struggled up to now, it may be to do with the fact that it is a social construct for governing relationships between individuals, and thought is—or should be—as private as it gets.
But there is much that the law can achieve. In its binding and enforceable character, it may be one of the best tools we have to challenge the 21st century’s most powerful interests, if we can deploy it effectively. The European Convention on Human Rights is sometimes called a “living instrument”; another useful description is that of the “living tree”. Human-rights instruments must grow, within natural confines determined by their fundamental structure. We need another burst of growth to catch up with where technology is today, building on the hard work done by reformers of decades past.
That will involve disentangling freedom of thought from other rights, so as to afford it more dedicated protection. It will mean thinking carefully about what informed consent looks like. And it will mean renewed emphasis on the legal principle that governments, as well as refraining from inflicting harm, have an active duty to prevent others inflicting it—whether that’s Facebook, BrainCo or anyone else.
Achieving such change won’t be easy. Tech companies will be loath to relinquish their grip on personal data, which serves, after all, as the basis of their business models. Governments may be hesitant to regulate for fear of shutting out innovation or incurring the wrath of a powerful industry. Besides, with such radically higher salaries on offer for corporate tech jobs than regulatory ones, governments may simply lack the expertise required to take on platforms advancing at such breakneck speed.
However, digital-rights conferences including RightsCon, whose annual gathering in June saw participants join from 174 countries, can help to shape the discussion. While activists such as Duncan McCann—who was the representative claimant in a recent challenge to the way YouTube tracks children, and has since lodged a formal complaint with the Information Commissioner’s Office accusing the platform of harvesting children’s data—hope to use the law to insist on new protections.
Thankfully, it is these people who are gradually winning the argument—and it must be won. Freedom of thought is not just a human right, but the engine of human development. It is the driving force behind all society’s innovations, including those made by the tech companies themselves.
But time is running short to guide the direction of at least some of these innovations before their harmful effects are encoded into our daily lives; to ensure that technology works in service of, rather than opposition to, human progress. Alegre has issued an inspiring rallying call. Now we have to put the law to work.
