This glossary defines the twenty most important terms in attachment theory, the framework developed by John Bowlby and Mary Ainsworth that explains how early caregiver relationships shape our capacity for love, trust, and emotional regulation across the lifespan. Each entry covers what the term means, who originated it, and why it matters for understanding your relationships today. Attachment theory is the most empirically validated framework in relational psychology, with over sixty years of longitudinal research (Sroufe, Fraley, Waters) confirming that early attachment patterns predict adult relational outcomes at rates far above chance. Whether you are trying to understand your own patterns, make sense of a partner's behavior, or find language for a therapist, these terms form the essential vocabulary. Hazan and Shaver (1987) extended attachment theory to adult romantic relationships, and since then roughly 45 percent of adults show secure patterns while 55 percent carry some form of insecure attachment, according to meta-analyses by Mikulincer and Shaver. Use this glossary as a reference: bookmark it, return to specific terms when you need them, and remember that attachment patterns are not life sentences. Earned secure attachment research (Roisman et al.) confirms that change is possible through therapy, reflection, and corrective relational experiences.

1. What Does Secure Attachment Mean?

Secure attachment describes the pattern in which a person comfortably seeks closeness, trusts others, and feels deserving of love. Coined by Mary Ainsworth in her Strange Situation studies (1978), secure attachment develops when caregivers respond reliably and warmly. Roughly 55 to 60 percent of the general population shows secure patterns, per Mikulincer and Shaver meta-analyses. It predicts better mental health, lower divorce rates, and higher life satisfaction. Citation: Ainsworth, Blehar, Waters and Wall, Patterns of Attachment (1978).

2. What Is Anxious Attachment?

Anxious attachment (also called preoccupied or ambivalent) describes a pattern marked by fear of abandonment, hypervigilance to rejection cues, and a tendency to seek excessive reassurance. It develops from inconsistent caregiving. Mikulincer and Shaver (2007) identified it with hyperactivating strategies of the attachment system. Roughly 20 percent of adults show this pattern. It matters because it drives the pursuit dynamic in relationships. Citation: Mikulincer and Shaver, Attachment in Adulthood (2007).

3. What Is Avoidant Attachment?

Avoidant attachment (or dismissive) is the pattern of emotional self-reliance, discomfort with intimacy, and deactivation of attachment needs. It develops when caregivers rejected bids for closeness. Roughly 25 percent of adults are dismissive. Bowlby called this defensive exclusion. It matters because avoidants often feel nothing is wrong while partners feel abandoned. Citation: Bowlby, Attachment and Loss Volume 1 (1969).

4. What Is Fearful-Avoidant Attachment?

Fearful-avoidant (or disorganized in adults) combines anxious craving with avoidant fear: the person wants closeness and simultaneously fears it. Kim Bartholomew (1991) identified the category. It is strongly linked to childhood trauma and affects roughly 5 to 10 percent of adults. It matters because it explains the confusing push-pull that some survivors experience in love. Citation: Bartholomew and Horowitz, Journal of Personality and Social Psychology (1991).

5. What Is Earned Secure Attachment?

Earned secure describes people who had insecure childhood attachments but developed secure patterns as adults through therapy, reflection, or corrective relationships. Mary Main and colleagues identified it through the Adult Attachment Interview. Roisman et al. (2002) confirmed that earned secure adults function as well as continuously secure adults. It matters because it proves attachment is not destiny. Citation: Roisman et al., Child Development (2002).

6. What Is Disorganized Attachment?

Disorganized attachment (Main and Solomon, 1986) describes the pattern seen in roughly 15 percent of infants where the caregiver is both source of comfort and source of fear. Children show contradictory behaviors (approaching while turning away). It is the strongest attachment predictor of later psychopathology. Citation: Main and Solomon in Affective Development in Infancy (1986).

7. What Was the Strange Situation?

The Strange Situation is the observational protocol Mary Ainsworth designed in 1969 to assess infant attachment. A mother and twelve-month-old enter a lab room, a stranger arrives, the mother leaves briefly, then returns. How the baby responds to reunion reveals secure, anxious, or avoidant patterns. It remains the gold standard for measuring infant attachment. Citation: Ainsworth and Wittig, Determinants of Infant Behaviour (1969).

8. What Is an Internal Working Model?

Internal working model (Bowlby, 1969) is the mental template of self, others, and relationships that a child builds from early caregiving experiences. It becomes the unconscious script guiding adult relationships. People with negative models of self tend toward anxious patterns; those with negative models of others tend toward avoidant. It matters because therapy often works by updating these models. Citation: Bowlby, Attachment and Loss (1969).

9. What Is an Attachment Figure?

An attachment figure is the specific person a child (or adult) turns to for comfort, protection, and security. Bowlby described a hierarchy: primary, secondary, and tertiary figures. In adulthood, romantic partners typically become the primary attachment figure. It matters because losing an attachment figure triggers grief responses measured in brain imaging studies by O'Connor and colleagues.

10. What Is a Secure Base?

A secure base (Ainsworth, 1967) is the attachment figure from whom a child explores the world, confident they can return for safety. In adult relationships, partners function as secure bases when they support each other's growth. Feeney and Thrush (2010) showed secure-base partners predict career and life exploration. Citation: Feeney and Thrush, Journal of Personality and Social Psychology (2010).

11. What Is a Safe Haven?

Safe haven is the second attachment function (Ainsworth): the figure to whom we turn when distressed for comfort. Secure base is about exploration; safe haven is about refuge. Both functions are required for healthy attachment. Adults who lack a safe haven partner show elevated cortisol and depression rates in Coan's hand-holding fMRI studies.

12. What Is Mirroring in Attachment?

Mirroring is the parent reflecting back the infant's emotional state through facial expression and voice, helping the child learn to identify feelings. Daniel Stern and Peter Fonagy developed this concept. Lack of mirroring contributes to alexithymia and borderline features. It matters because good therapy and good partnerships involve mirroring. Citation: Fonagy et al., Affect Regulation, Mentalization and the Development of the Self (2002).

13. What Is Attunement?

Attunement is the caregiver's moment-to-moment matching of the child's emotional rhythm and intensity. Stern called it affect attunement (1985). It is more specific than mirroring: it involves pacing. Schore's research (2003) links attunement to right-brain development. It matters because attuned relationships regulate the nervous system.

14. What Is Rupture and Repair?

Rupture and repair (Tronick, 1989) describes the cycle where caregivers inevitably miss attunement (rupture) and then restore connection (repair). Tronick's Still Face experiment showed that repair, not perfection, builds secure attachment. It matters because it gives hope to parents and partners who fail daily. Citation: Tronick, American Psychologist (1989).

15. What Is Co-Regulation?

Co-regulation is the process of two nervous systems soothing each other. Stephen Porges's polyvagal theory explains it through vagal tone and facial signaling. Infants cannot self-regulate; they borrow their caregiver's regulation. Adult partners co-regulate through touch, voice, and presence. Citation: Porges, The Polyvagal Theory (2011).

16. What Are Hyperactivating Strategies?

Hyperactivating strategies (Mikulincer and Shaver) are the anxious attachment tactics of intensifying bids for connection: calling repeatedly, escalating emotion, protest behavior. They aim to force the attachment figure to respond. They matter because recognizing them is the first step to interrupting them in adult relationships.

17. What Are Deactivating Strategies?

Deactivating strategies are the avoidant tactics of suppressing attachment needs: withdrawing, emotional shutdown, focusing on flaws. Mikulincer and Shaver identified them as defenses against the pain of unmet attachment. Recognizing them helps avoidants understand their own numbness.

18. What Is Mentalization?

Mentalization (Fonagy) is the capacity to understand your own and others' behavior in terms of mental states (thoughts, feelings, intentions). Secure attachment builds mentalization; trauma damages it. Mentalization-based therapy (MBT) was developed by Fonagy and Bateman for borderline personality. Citation: Fonagy and Bateman, Mentalization-Based Treatment (2006).

19. What Is Emotional Availability?

Emotional availability describes a caregiver's openness to the child's emotional experience without becoming overwhelmed or dismissive. Biringen's Emotional Availability Scales operationalized it. It is the practical, observable form of attunement and predicts child outcomes across cultures.

20. What Is Proximity Seeking?

Proximity seeking is the attachment behavior of moving toward the attachment figure when threatened or distressed. Bowlby considered it the core attachment behavior. In adults, it appears as wanting to be near a partner when sick, scared, or sad. It is biologically ancient and universal. Citation: Bowlby, Attachment and Loss (1969).