History & Development
The origins of
mentalizing.
How do we understand what is happening in another person's mind?
Mentalizing is the process through which we understand our own behavior and the behavior of others in terms of internal mental states, including thoughts, emotions, beliefs, desires, and intentions. It is both a psychological capacity and a fundamentally social process. Mentalization-Based Treatment (MBT) developed from research examining this capacity, especially its relationship to emotional development, attachment, and psychological distress.
Philosophy & Social Understanding
Long before MBT emerged, philosophers examined how human beings understand consciousness, intention, and the experiences of others.
Nineteenth-century philosopher Franz Brentano contributed to the study of intentionality, the idea that mental states are directed toward something. Later developments in philosophy and psychology explored how we attribute beliefs and intentions to other people.
Theory of Mind & Development
Research into Theory of Mind explored how people recognize that others possess beliefs, knowledge, and perspectives that may differ from their own.
Researchers including Uta Frith investigated social understanding through cognitive and developmental approaches. Peter Fonagy also examined mental states through psychoanalytic, attachment, and developmental perspectives.
The Development of MBT
Peter Fonagy and Anthony Bateman developed Mentalization-Based Treatment through clinical work with individuals diagnosed with borderline personality disorder (BPD).
Their work proposed that difficulties sustaining mentalizing, especially during emotionally intense interpersonal experiences, could help explain problems with emotional regulation, self-understanding, and relationships.
MBT was developed to support the recovery of reflective understanding when stress or attachment-related experiences disrupt that capacity.
An Evolving Clinical Framework
Mentalizing theory now informs work across psychotherapy, psychiatry, developmental psychology, and professional education.
MBT has also been adapted and studied in additional settings, including work with adolescents and families. Its most established clinical research tradition concerns personality disorders, particularly BPD.
The underlying focus remains consistent: strengthening our capacity to understand ourselves and others, especially when that understanding becomes difficult.
The Clinical Framework
Four dimensions
of mentalizing.
Mentalizing is not a fixed ability. It changes according to our emotional state, relationships, and circumstances.
Contemporary mentalizing theory describes four interacting dimensions. Each represents a different way of processing psychological experience. Effective mentalizing involves moving flexibly between these dimensions rather than relying on one perspective.
Automatic & Controlled
From intuition to reflection.Automatic mentalizing allows us to interpret expressions, tone, and social interactions quickly, often without deliberate thought. Controlled mentalizing involves intentionally slowing down to examine what we or another person might be experiencing. During emotional stress, rapid interpretations can dominate when more deliberate reflection would be helpful.
Self & Other
Recognizing separate perspectives.Mentalizing involves understanding our own mental states while recognizing that other people possess distinct internal experiences. Challenges may emerge when our perspective feels like the only possible explanation, or when another person's emotions become so prominent that we lose track of our own.
Cognitive & Affective
Thinking about feelings and experiencing them.Cognitive mentalizing involves identifying and reasoning about mental states. Affective mentalizing involves recognizing and engaging with their emotional qualities. Someone may understand an emotion intellectually while feeling disconnected from it, or experience intense emotion without being able to reflect on its meaning.
Internal & External
Looking beyond what can be seen.External mentalizing draws on observable behavior, expressions, speech, and physical actions. Internal mentalizing considers experiences that cannot be directly observed, including beliefs, feelings, and intentions. Because behavior does not always reveal someone's inner experience, curiosity helps us reconsider our initial assumptions.
The goal is flexibility, not perfection. Effective mentalizing involves moving between different perspectives while recognizing that our interpretations can change as we learn more.
Emotion, Stress & Understanding
When mentalizing
becomes difficult.
Our capacity to understand mental states is particularly sensitive to emotional arousal and important relationships.
Attachment-related experiences, such as feeling rejected, misunderstood, or disconnected, can intensify emotion and make reflective thinking harder. Under these conditions, assumptions may become rigid, thinking may disconnect from emotional experience, or behavior may be understood primarily through observable actions. MBT describes three patterns that can emerge when mentalizing is disrupted. These are not diagnoses, and temporary lapses can occur in anyone.
Psychic Equivalence When a thought feels like a fact.
Psychic equivalence describes a state in which internal experience is treated as a direct representation of external reality.
Feelings and interpretations become difficult to distinguish from facts. Alternative explanations may seem unlikely, especially when emotions are intense.
Someone feels rejected after a message goes unanswered and becomes certain that the other person is angry, even though several explanations remain possible.
Pretend Mode When thinking becomes disconnected from lived experience.
Pretend mode involves a disconnection between reflection about mental states and the emotional or external experiences they are intended to describe.
An individual may discuss feelings and relationships in considerable intellectual detail without connecting those explanations to what they actually experience.
In clinical work, this can resemble psychological insight without corresponding emotional engagement.
A person can explain several theories about why an argument occurred, but struggles to identify what they felt during the interaction.
Teleological Mode When actions become the evidence of feelings.
Teleological mode places particular importance on observable actions and concrete outcomes.
Internal states may become difficult to recognize or trust unless they are demonstrated through physical behavior. Feelings and intentions may seem less meaningful than what someone visibly does.
Someone struggles to believe they are cared for unless another person demonstrates that care through a specific action, even when affection has been expressed verbally.
Restoring mentalizing. A central aim of MBT is to help individuals recognize when emotional intensity has disrupted reflection, regain a manageable level of emotional arousal, and return to a more flexible understanding of experience.
MBT in Clinical Practice
Understanding is something
we develop together.
Mentalization-Based Treatment places particular emphasis on how understanding develops between patient and therapist.
Rather than beginning with a fixed explanation for someone's experience, MBT encourages a collaborative exploration of emotions, interpretations, and relationships. The therapist remains attentive to the patient's emotional state and capacity for reflection, adjusting the conversation when emotional intensity makes mentalizing more difficult.
The Not-Knowing Stance
The therapist brings clinical knowledge while recognizing that another person's inner experience cannot be known with certainty. This does not mean pretending to have no understanding. It means approaching interpretations with humility, curiosity, and openness to correction.
Attachment & Emotional Arousal
Important relationships can intensify emotional responses. When feelings become overwhelming, mentalizing may temporarily become less flexible. MBT attends to these shifts, helping patients remain engaged with emotion while recovering the capacity to reflect.
Recognizing & Repairing Misunderstandings
Misunderstandings can arise within therapy itself. Instead of treating them as failures, MBT uses these moments as opportunities to explore assumptions, acknowledge different perspectives, and restore mutual understanding.
How does MBT work in practice?
Bateman and Fonagy describe a flexible sequence of therapeutic interventions. The approach begins with emotional understanding and moves toward more complex reflection when the person is able to engage with it.
Begin with Empathy
Recognize and validate the person's current emotional experience without assuming its meaning is already known.
Explore & Clarify
Examine what happened, consider different perspectives, and gently question interpretations that may have become fixed.
Attend to Emotion
Identify the feelings present in an experience and consider how emotional intensity influences understanding and behavior.
Reflect on the Relationship
When appropriate, explore what is happening between patient and therapist, including misunderstandings and differing interpretations.
Mentalizing is not about knowing more about another person's mind. It is about becoming more thoughtful about what we cannot know for certain.
What does the research tell us?
Mentalization-Based Treatment was originally developed as a structured psychotherapy for borderline personality disorder. Early clinical trials examined combinations of individual and group treatment and reported improvements in important outcomes, including self-harm and psychiatric hospitalizations.
In their 2013 review, Bateman and Fonagy also emphasized limitations in the available research, particularly the need for independent replication and clearer evidence about how changes in mentalizing contribute to treatment outcomes.
MBT has since informed work in additional clinical and developmental settings. However, findings from structured research programs should not be assumed to apply equally to every adaptation or individual practice.
About this overview: This page explains the theory and clinical principles of MBT. It does not imply that every patient receives the same treatment format, schedule, or combination of services.
Academic Inspiration & References
Bateman, A., Fonagy, P., Campbell, C., Luyten, P., & Debbané, M. (2023). A History of Mentalizing and Mentalization-Based Treatment . In Cambridge Guide to Mentalization-Based Treatment (MBT) (Chapter 1, pp. 1–3). Cambridge University Press.
Bateman, A., & Fonagy, P. (2013). Mentalization-Based Treatment . Psychoanalytic Inquiry, 33 (6), 595–613. DOI: 10.1080/07351690.2013.835170 .