The Méndez Principles: Beware Crossing the Line to Psychological Torture

CERL is pleased to present this article (and the entire Just Security series) based on the newly-released Principles on Effective Interviewing for Investigations and Information Gathering, also known as The Méndez Principles. Named for Juan Méndez, the former UN Special Rapporteur on Torture who in 2016 called for the creation of a universal protocol for lawful and humane interviewing standards, the principles provide guidance on conducting non-coercive and rapport-based interviews with legal and procedural safeguards. CERL has been an advocate of Mr. Méndez’s call for the protocol and welcomed him as the keynote speaker at CERL’s 2018 conference on interrogation and torture.–Claire O. Finkelstein, CERL Academic Director


The Méndez Principles: Beware Crossing the Line to Psychological Torture, by Nils Melzer and Steven J. Barela, was originally published in Just Security.

(Editor’s note: This article is part of a Just Security
series on the newly released “Principles on Effective Interviewing for Investigations and Information Gathering,” an expert-led initiative responding to a 2016 appeal to the U.N. General Assembly by then-U.N. Special Rapporteur Juan E. Méndez to develop such standards. The series outlines the origins and the scientific, legal, and ethical underpinnings of the guidelines, also known as the “Méndez Principles” in honor of its co-chair.)

Every year on the June 26 commemoration of the United Nations International Day in Support of Victims of Torture, we are painfully reminded of the countless contexts in which torture and ill-treatment continue to be practiced with impunity worldwide. Psychological torture is a particularly perfidious form. It is important to guard against the many slippery slopes that are conducive to this type of abuse.

During the Cold War era, many governments carried out “mind control” experiments on thousands of prisoners, psychiatric patients, and volunteers who were unaware of the serious health risks or of their true nature and purpose (see e.g., here, here, here and here). These scientific trials were part of large classified projects that followed in the steps of those conducted under the Nazi regime in the Dachau concentration camp with the aim of developing more effective methods than physical torture to break the most resistant prisoners. Today these abhorrent techniques have proliferated as interrogation methods, not because they are effective at producing reliable information (quite the contrary, as discussed previously in this series, scientific studies demonstrate that, among other things, the agony of torture diminishes the cerebral capacity required to recall true information). Rather, these abuses achieve the true purpose of all torture – the complete subjugation of the victim – without leaving readily identifiable physical traces.

These practices, which avoid using the body as a conduit of the inflicted pain and suffering, are best classified as “psychological torture.” Their characteristics were fleshed out under human rights law in a March 2020 report by the United Nations Special Rapporteur on torture and other cruel, inhuman or degrading treatment or punishment (co-author Nils Melzer). A recent documentary film that inspired this work, Scottish director Stephen Bennett’s Eminent Monsters: A Manual For Modern Torture, is a tour de force that leaves audiences both shaken and educated. The film documents and follows the collusion between doctors and the governments of the United States, the U.K., and Canada, in now notorious cases ranging from the U.S. naval detention center at Guantánamo Bay, to a mind-control laboratory in Montreal and the “hooded men” in Belfast interrogation centers, and beyond. The experiments using sensory deprivation, forced comas, and LSD injections have been used to construct various forms of modern psychological torture.

In regards to the “war on terror,” Georgetown Law Professor David Luban and Military Commissions Defense Organization Resource Counsel and former U.S. Air Force officer Katherine Newell have argued that the “family of interrogational abuses” employed against high-value detainees “unequivocally” meet the legal definition of mental torture under U.S. law. Their claim is documented with research into tens of thousands of pages of declassified government sources, and turns on the fact that the U.S. torture statute includes a clause that Congress inserted in its definition of mental torture: “procedures calculated to disrupt profoundly the personality.” This important work reveals that personality disruption was exactly the goal through psychological debilitation. In the words of the KUBARK interrogation manual from the CIA that served as part of the research grounds for the recent torture program, “As the interrogatee slips back from maturity toward a more infantile state, his learned or structured personality traits fall away.”

Legal groundwork can help in understanding the recent evolution of torture and why it is essential to properly categorize this deeply damaging practice. Moreover, a full appreciation of the fault lines between non-coercive interviewing and psychological torture at the “lower intensity” end of the spectrum is paramount. That is, States are likely to look for ways to skirt the limitations of non-coercive interviewing through methods of psychological torture that aim to erode the victim’s personality, identity, and willpower without being interpreted as coercive. Whether such misconceptions are motivated by conscious malice, or by unconscious patterns of self-deception and denial of reality, which have been identified as a primary obstacle for the universal eradication of torture, it is surely wise to have our eyes open to the ever-shifting excuses and creation of loopholes to inflict cruelty in the effort to implement the new Principles on Effective Interviewing for Investigations and Information Gathering.

Too Often Brushed Away

The mandate of the Special Rapporteur has long recognized the conceptual distinction between physical and mental or “psychological” torture, and particular attention has been placed on the worrisome fact that the latter form of ill-treatment has often been “brushed away as mere allegations,” since it leaves no obvious physical scars. Even if States have generally been open to acknowledging the problem of psychological torture, national practice has tended to trivialize any treatment that does not include corporal pain or suffering. At the same time, various disciplines (e.g. medicine, psychology, ethics, philosophy, sociology) have found it useful to distinguish this type of conduct for diverse purposes, thus giving rise to differing interpretations.

Despite all of this, it should not be overlooked that torture is a unified legal concept. That is, drawing a distinction between physical and psychological torture by no means changes the universal prohibition or the legal obligations derived from it. There is no hierarchy of severity as the “two types are interrelated and ultimately, both have physical and psychological effects.” Torture is never an exclusively corporal ordeal, but always purposefully targets the mind and emotions of the victims themselves or of third persons forced to witness the act. Torturers always intend to subjugate through a demonstration of absolute power over complete helplessness. The only difference between physical and psychological torture is that the latter achieves this effect without using the body as a vehicle. In other words, psychological torture is a sub-category to the generic concept of torture.

Yet, “psychological torture” has not been a technical term of international law. In view of ameliorating this lacuna, the Special Rapporteur’s 2020 report accordingly puts forward the view that under human rights law,

“psychological torture” should be interpreted to include all methods, techniques and circumstances which are intended or designed to purposefully inflict severe mental pain or suffering without using the conduit or effect of severe physical pain or suffering. Conversely, “physical torture” should be interpreted to include all methods, techniques and environments which are intended or designed to purposefully inflict severe physical pain or suffering, regardless of the parallel infliction of mental pain or suffering.

Despite significant overlaps, psychological torture should not be simply conflated with “no marks” and “no touch” torture. Reed College Professor Darius Rejali’s magisterial work has shed light on the fact that democracies have shifted to using this kind of “clean” or “stealth” torture in the presence of a free press and the rise of public-monitoring mechanisms. While such “no marks” torture aims to avoid visible traces, it may still rely on the physical body as a conduit of pain or suffering, such as through stress positions, suffocation, or sleep deprivation.

By contrast, psychological torture avoids the physical body and attacks the mind directly. It aims not only to avoid producing the evidence for the crime but, even more radically, to escape the definition of the crime altogether. Intimidation, humiliation, isolation, and arbitrariness can go a long way before being perceived as torture, far longer than any victim’s resilience could possibly last. Such abuse may be called “deep interrogation,” “preventive segregation,” “administrative detention,” or similar, but is rarely seen for what it really is: plain and simple torture. This is the deceptive power of psychological torture, which allows not only the involved officials, but also judges, the media, and the general public to maintain a convenient illusion of due process and the rule of law while practicing nothing less than willful ignorance.

Predominant Methods

The 2020 report duly applies the constitutive elements of mental suffering, which has both subjective and objective aspects, and the need for case-by-case assessment of severity, along with an elaboration on the rudiments of powerlessness, intentionality, and purposefulness. Furthermore, it clarifies that the exception of “lawful sanctions” does not provide a “carte blanche” to national legislation, but excludes only those legal measures from the definition of torture that are consistent with the Standard Minimum Rules for the Treatment of Prisoners, known as the Nelson Mandela Rules.

The report provides an easily accessible description of the predominant methods of psychological torture in seven sub-categories, each of which targets a particular, well-documented psychosocial need:

  1. Security (inducing fear, phobia, and anxiety)

Perhaps one of the most elementary forms of torture that impacts this need is the purposeful infliction of fear. There are a limitless variety of techniques that can include everything from threats and withholding or distorting information to provoking personal or cultural phobias.

  1. Self-determination (domination and subjugation)

Applied in nearly all circumstances of torture is the deprivation of control over one’s schedule, from bodily functions of eating, sleeping, and bladder and bowel movements to imposing impossible choices that force the victim to participate in their own torture. This is analogous to what has been described as part of the “learned helplessness” used in the recent CIA torture program.

  1. Dignity and identity (humiliation, breach of privacy, and sexual integrity)

This is closely related to removal of personal control but is even more transgressive in that it means to target the victim’s sense of identity and self-worth. It can be carried out through constant surveillance, public shaming, forced nudity and masturbation, or a breach of cultural and sexual taboos.

  1. Environmental orientation (sensory manipulation)

As sensory stimuli and environmental control are a basic human need, their deprivation and manipulation can cause severe suffering. This can be achieved through constant light or dark, the removal of all sound in one’s cell, or the use of hooding, blindfolding, gloves, and earmuffs. This is found at the very interface of psychological and physical torture.

  1. Social and emotional rapport (isolation, exclusion, betrayal)

Another frequent target of attack is a person’s need for social and environmental connection. This can be realized through incommunicado detention or solitary confinement (particularly traumatic if prolonged and indefinite), or by fostering and then betraying a detainee’s trust, or forcing them to participate in the abuse of others.

  1. Communal trust (institutional arbitrariness and persecution)

Since every human being needs to maintain a certain communal trust, this can be broken by arbitrary sanction or punishment. The most notable forms of this can occur through enforced disappearance, instrumentalizing prolonged detention, or imposing grossly disproportionate penalties in comparison to the offense.

  1. Torturous environments (accumulation of stressors)

In practice, victims are almost always subjected to more than one method of torture. It is often the combination of psychological and/or physical techniques, sometimes used over prolonged periods of time, that push a treatment beyond the “severity” threshold. Hence, due consideration of context must always be given for a legal analysis.

Defining and discussing psychological torture as distinct from physical torture is neither a purely theoretical exercise, nor does it suggest any difference in terms of cruelty, impermissibility, or legal consequences. Rather, the point of this discussion is to demonstrate how broad the substantive scope of the prohibition really is. It also offers political leaders, judges, and other officials an analytical framework facilitating the recognition, prevention, and prosecution of techniques, methods, or circumstances that amount to torture despite the absence of directly inflicted physical pain or suffering. Last but not least, it also empowers civil society, the media, and dedicated oversight mechanisms to keep a more vigilant eye on State practices that aim to erode the fault lines between legitimate non-coercive interviewing and prohibited methods of psychological manipulation that can only be described as torture.

(A launch event for the Méndez Principles took place on June 9th featuring speakers including U.N. High Commissioner for Human Rights Michelle Bachelet, Deputy Foreign Minister for Multilateral Affairs of Costa Rica Christian Guillermet Fernández, Ambassadors to the U.N. Mona Juul of Norway and Ramses Joseph Cleland of Ghana, U.N. Special Rapporteur on Torture Nils Melzer, and former U.N. Special Rapporteur on Torture Juan E. Méndez. A recording of the event is available here.)

About the Authors

Nils Melzer

Nils Melzer (@NilsMelzer) is UN Special Rapporteur on torture and other cruel, inhuman or degrading treatment or punishment. He has been Swiss Human Rights Chair at the Geneva Academy since March 2016. He also is Professor of International Law at the University of Glasgow and Vice-President of the International Institute of Humanitarian Law in San Remo.

Steven J. Barela

Steven J. Barela (@StevenJBarela) is a Senior Research Fellow at the University of Geneva in the Global Studies Institute and a member of the Law Faculty in the Department of History and Philosophy of Law. He is also an Associate Research Fellow at the Geneva Academy of International Humanitarian Law and Human Rights.


CERL is grateful to Steven J. Barela, Senior Research Fellow at the University of Geneva in the Global Studies Institute, for his work in the publication of these articles on The Rule of Law Post. This work, which includes serving as Editor leading the Chairpersons’ Editorial Group of the Méndez Principles initiative, is supported by the Swiss National Science Foundation.

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