Attachment Theory: What It Is & How It Shapes Adult Relationships

John Bowlby developed attachment theory through a series of studies examining the effects of separation between infants and their parents during the first years of a child’s life. When a baby cries or clings to their parent, it isn’t just a random reaction—it’s a survival instinct. John Bowlby, the father of attachment theory, realized that these behaviors are biological ‘SOS signals’ designed to keep us close to the people who protect us. Bowlby believed these behaviors were likely reinforced through natural selection, enhancing the child’s chances of survival.

At length, Bowlby arrived at attachment theory by combining ideas from psychoanalysis and ethology. Basically, Bowlby argued that “affectional ties between children and their caregivers have a biological basis which is best understood in an evolutionary context.” He explained that “there is a genetic bias among infants to behave in ways which maintain and enhance proximity to caregivers and elicit their attention and investment” (Goldberg, 1991, p. 393).

The Early Beginnings

In a 1958 paper, John Bowlby emphatically defended his research writing that there are “no grounds for complacency.” Bowlby warns the “disturbances (found) are serious and affect a far from negligible portion of children.” He encourages that as far as “measures can be taken to prevent them it remains urgent they be taken” (Bowlby, 1958, p. 211).

John Bowlby in an earlier paper wrote that if the relationships between a child and his mother and other members of the family in the child’s early life are happy then, Bowlby believed, “that there is likelihood that the child will be able to develop similar satisfactory relationships in later life with people outside the immediate circle of his own family.” He continued, “conversely, if this relationship develops adversely, we believe that he will probably become disturbed emotionally to a greater or lesser degree, and may be confronted throughout life by difficulties in his personal relationships” (Bowlby, 1954, p. 59-60).

Mother Child Attachment

Early attachment theory research concentrated on mother-child attachment but the theory relates to the formation, maintenance, and disruption of bonds throughout our lives.

The heart and soul of attachment theory is that a child’s early relationships, especially those between the child and a primary caregiver, matter. These relationships cast a long shadow over the relationships the child will experience for the remainder of their life.

Susan Goldberg explains that “as a child’s locomotor, linguistic and social skills develop, the goals of attachment system are modified to allow for longer separations over greater distances.” She continues “cognitive components play a more dominant role and proximity plays a less important role in moderating attachment behavior” (Goldberg, 1991, p. 393).

Dyadic Regulation

Attachment serves as the earliest and most impactful form of dyadic regulation because a baby relies entirely on the bond with a caregiver to manage distress that they cannot yet handle on their own. In this dynamic, the brain of a calm, well-regulated parent acts as a “hidden regulator,” synchronizing with the infant to soothe them and teach their developing brain how to calm down. This co-regulation is essential because it provides the conditioning that eventually allows a child to move from relying on others to possessing the ability to self-regulate their own nervous system (Murphy, 2022a).

Linda Graham, a professor in the School of Early Childhood and Inclusive Education, wrote:

“Dyadic regulation is the process by which the brain of a calm, well-regulated parent teaches the brain of a fussy baby to calm down and soothe itself: it provides the conditioning that enables the baby’s prefrontal cortex to learn to regulate its autonomic nervous system (ANS)” (Graham, 2013).

What is Attachment Theory? The Foundation of Emotional Bonds

​Before we can understand attachment theory, we must first understand the psychological term of attachment. Mary Ainsworth describe attachment as a tie that binds “together in space and endures over time” (Mooney, 2009).

John Bowlby defines attachment as “the dimension of the infant-caregiver relationship involving protection and security regulation. Within this theoretic framework, attachment is conceptualized as an intense and enduring affectional bond that the infant develops with the mother figure, a bond that is biologically rooted in the function of protection from danger” (Mooney, 2009).

​Attachment Behaviors

William J. Lyddon of University of Southern Mississippi defines attachment behaviors as a “neurologically-based behavioral system that has evolved to promote proximity to a caregiver” (Lyddon, 1995). Attachment occurs because the infant and mother naturally use behaviors that create a bond.

In 1969, Bowlby wrote in his classic book Attachment and Loss (vol 1) that several infant common infant behaviors (smiling, crying, approaching, clinging, etc…) predictably lead to the mother maintaining a degree of proximity to the baby. He called these behaviors “attachment behaviors” (Bowlby, 1983). Bowlby repeatedly throughout his work reaffirmed his belief in “a innate need and impulse to achieve and maintain good relationships with other people, namely, relationships of confidence, mutual respect, and mutual affection” (Bowlby,1954, p. 60).

Bowlby wrote that the young child “is born with a strong bias to approach certain classes of stimuli, notably the familiar, and to avoid other classes, notably the strange.” He explains that this function is primarily driven by survival needs of protection from predators (Bowlby, 2005).

A 1973 paper authored by Donelda Stayton, Mary Ainsworth, and Mary Main define attachment behaviors, referring to adolescents and adults are behaviors that “at first promote proximity to companions generally and later are directed chiefly toward one or a few attachment figures.” In relation to the infant, they explain, “attachment behaviors are believed to serve the function of protecting him from danger, and thus favor survival” (Stayton et al., 1973, p. 213).

Belongingness and Attachment

We ache to belong. Within our genetic makeup is built in forces that drive us to attach to others, with the first figure of attachment typically being the mother.

As the child develops a grouping of observable behaviors occur around separation and reunion after separation. These behaviors were targeted for attachment theory research. Attachment scientists observed a child’s reaction to momentary separations from attachment figures and the subsequent reunion, recording and classifying behaviors.

Secure Base

As a child develops proximity takes on new conceptual meanings. For the infant, proximity is completely physical. The safety is derived from physical touch. As the child grows, however, proximity may be achieved from knowledge of a secure reunion, available whenever needed.

T. Franklin Murphy wrote, “as a securely attached child becomes comfortable with their environment, they leave the safety of their mother’s arms and begins to explore. When the safety of the environment is disrupted by a surprising element, the child quickly returns to their mother for reassurance” (Murphy, 2022). 

Mary Ainsworth (1913-1999), a developmental psychologist, “​observed this behavior in so many of the infants that it led her to hypothesize that babies use their mothers as a secure base to depart from and return to in their explorations of the world” (Ainsworth, 1979; Mooney, 2009).

As a securely attached adult, we utilize a wide variety of means to reaffirm attachment and soothe separation fears. We may find security through a phone call or text message, even when we may be on the other side of the world on a business trip. We draw many benefits from the safety of a secure base.

Internal Working Model

During the dawning moments of interaction between a child and caregiver, the child begins to form an internal working model of the world. Through this lens they will interpret future interactions with others outside of the parent child bond. Jonathan Haidt, an associate professor of psychology at the University of Virginia, explains that internal mental models are “a property that emerges gradually during thousands of interactions” (Haidt, 2003). 

We can think of an internal working model as a mental “blueprint” or “map” that an individual constructs based on thousands of daily interactions with their primary caregivers during early childhood (Cain, 2006). Daniel Siegel explains that these mental models are “a neural firing pattern, that creates in the person a felt sense that others are dependable and can and should be relied upon as needed” (Siegel, 2020).

An Organizational Structure for Understanding the World

This internal world serves as a core organizational structure that allows a person to simulate future happenings and predict how others will behave, specifically answering fundamental questions about whether the self is worthy of care and if others can be trusted to provide it,,.

Bowlby wrote:

“The picture presented can be looked upon as a much modified and updated variant of traditional psychoanalytic thinking in which great emphasis is placed on the particular pattern into which each personality comes to be organized during the early years, with its own distinctive working models or, to use the traditional term, internal world, and on the strong influence thereafter that each individual’s models have in shaping his or her life” (Bowlby, 1988).

Functioning largely beneath conscious awareness, these models act as “structures of meaning” that guide perceptions and expectations throughout life, essentially teaching the brain “what a relationship is” so it can navigate social complexities without having to relearn the rules with every new encounter (Murphy, 2022b).

Who Founded Attachment Theory? The Legacy of John Bowlby and Mary Ainsworth

John Bowlby (1907-1990)

British psychologist John Bowlby while working with a number of delinquents referred to a guidance clinic, he discovered an unusual proportion of the delinquents (in the clinic for stealing) had suffered prolonged separation from their mothers during their first five years of life. He also observed a number of these delinquents were unable to make permanent, mutually satisfying love relationships with other people.

Bowlby also discovered that the delinquent children that expressed an ‘affectionless character’ had been separated from their mothers for more than six months during early childhood. Bowlby quantified these observations by comparing histories of the delinquent children with non-delinquent children being cared for in the same clinic (Bowlby, 1944).

The differences were significant. Bowlby explained that the differences strongly suggested that “a break in the continuity of the mother-child relationship at a critical stage in the development of the child’s social responses may result in more or less permanent impairment of the ability to make relationships” (Bowlby, 1956).

Bowlby’s Early Work

During late 1940’s and the 1950’s Bowlby wrote a series of articles on homeless children, and maternal care. At the time, there were no theories attributing attachment to parental figures as a cause for emotional and behavioral disturbances. Bowlby did not feel his early writings introduced a new theory.

Bowlby’s work in the field of maternal care and child development continued throughout his life. Bowlby 1969 published work Attachment and Loss (volumes 1 and 2) established the structural theory for continued research on attachment the continues to this day.

Bowlby expressed that his work brought to light the “deficiencies of the data and the lack of theory to link alleged cause and effect” in his early article Maternal Care and Mental Health and comprehensively in his later work Attachment and Loss.

John Bowlby is the father of modern attachment theory. While he slowly adjusted his original findings presented in his first papers during the 1940’s and 50’s, the original work changed the course of psychology, directing attention to the home and early bonding with prominent family members responsible for caring for the infant and young child.

Mary Ainsworth (1913-1999)

Mary Ainsworth answered an advertisement placed in the London Times by John Bowlby. Bowlby was seeking a research assistant. Ainsworth’s dedicated the remainder of her life to understanding and teaching the impact of early attachment of children to their caregivers.

“Ainsworth was convinced that observation of infants in their home environment contributed a more accurate way to assess emotional stability and attachments than focusing on the memories and dreams of insecure adults” (Mooney, 2009). 

Ainsworth conducted studies closely observing children with their mothers. She recorded findings from detailed observations of families while living in Uganda where she carried out her longitudinal field study of mother-infant interaction. She continued her storied career in Baltimore where she was an associate professor in developmental psychology at John Hopkins University.

​One of Ainsworth’s key contributions to the development of attachment theory was her strange situation research. Ainsworth designed the Strange Situation  Procedure to assess differences in attachment behavior of children during and after stressful encounters. From her strange situation studies, Ainsworth identified three attachment styles (secure attachment, anxious ambivalent attachment, and anxious avoidant attachment). These studies remain a staple of psychology 101 courses today.

Another key contribution to attachment theory is Ainsworth’s concept of secure base. T. Franklin Murphy wrote “with a secure base, we confidently explore, knowing we have a place of safety at our disposal whenever needed” (Murphy, 2022).

The Strange Situation: How Attachment Research Works

Much of the attachment research was qualitative not quantitative. Bowlby closely observed institutionalized children, obtaining detailed histories of their lives. Mary Ainsworth spend countless hours observing mother child interactions within the walls of their own homes.

Ainsworth’s strange situation procedures brought attachment research to the lab. Researchers specifically designed playrooms to alleviate anxiety, creating a better environment to examine young children’s separation and greeting behaviors when a stranger was present.

Future studies validated the early qualitative observations.

The 4 Attachment Styles: How Do You Connect with Others?

Ainsworth identified three different attachment orientations through her research, particularly with the strange situation procedure. These attachment styles displayed a diverse range of attachment behaviors when the children perceived an upcoming separation, after the separation occurred, and with the greeting after reunion from the separation. Afterwards, Ainsworth organized and grouped attachment behaviors into three different styles of attachment (secure attachment, anxious-ambivalent attachment, and anxious avoidant attachment). Later, Mary Main, a colleague of Ainsworth, added a fourth style (disorganized attachment).

Secure Attachment:

​Children who can depend on their caregivers show distress when separated and joy when reunited. In effect, the belief that a caregiver will return provides reassurance to the child. When frightened, securely attached children are comfortable seeking reassurance from caregivers. 

Securely attached individuals typically have established a secure base to draw resources from during stressful situations. They have an optimistic expectation that they possess or can find support. Intimacy, closeness, supportiveness, and trust are characteristic of secure peoples romantic relationships (Mikulincer et al., 1993).

Susan Goldberg, Ph.D., explains that “in the secure strategy, the attachment system is activated only when the infants security is threatened and subsides to give exploratory system free reign when the attachment figure (secure base) returns” (Goldberg, 1991, p. 394).

In Ainsworth’s original study, 65% of the babies exhibited a secure attachment pattern. Future studies replicated this finding. Generally, most the following studies categorized approximately the same percentage of children as securely attached.

Anxious-Ambivalent Attachment:

​These children become very distressed during separation or when a separation was anticipated. Additionally, they  expressed anger when their attachment figure returned. Goldberg explains that for these children “the attachment system is continuously activated at the expense of the exploratory system, even when to all outward appearances the child should be safe and comfortable” (Goldberg, 1991, p. 394-395).

The threshold to activate attachment behaviors (clinging, crying, etc…) is very low. Accordingly, the slightest perturbance ignites fear of abandonment and the child responds with attachment behaviors. 

T. Franklin Murphy wrote that in adult relationships, anxious love  often is accompanied by “dramatic swings from elation to biting fear.” He explains that these “extremities of emotions motivate unhealthy reactions—abstaining from love, fleeing from connection, manipulating attention, or finding non-threatening and unfulfilling partners” (Murphy, 2018). The anxiousness often leads to a lifetime of entangled relationships driven by panicked attempts to secure and maintain love.

In conclusion, one author wrote that “emotional instability, worry being abandoned, and jealousy characterized ambivalent peoples relationships” (Mikulincer et al., 1993). Professionals also refer to this this pattern of attachment as insecure, resistant, dependent or preoccupied. Overall, anxious ambivalent attachments occurred in roughly 14% of the children observed by Ainsworth.

Avoidant Attachment:

Researchers characterize the children of ambivalent attachment as having a low threshold for activating attachment behavior, in comparison, they see the avoidant children as having a high threshold. ​

The avoidant children defensively suppress attachment system activation “so the child appears to be exploring without concern for security, although he carefully monitors the attachment figure” (Goldberg, 1991, p. 394). Particularly noteworthy was that children with an avoidant attachment tend to avoid parents or caregivers when they return from separation. 

Fear of intimacy and difficulty depending on others characterized the avoidant attachment style. Tis style lends to defensive emotional detachment from relationships. ​Approximately 21% of the children observed by Ainsworth displayed an avoidant pattern of attachment.

Disorganized Attachment:

​Ainsworth’s colleague Mary Main later added a fourth category. In general, disorganized behaviors occur only briefly most often during the greeting or reunion with an attachment figure. Disorganized children lack a patterned strategy for dealing with separation. The child eventually settles and enters back into one of the three other attachment patterns. 

These children display confusing behaviors during the greeting phase of the strange situation, seeming disoriented or confused. They may avoid or resist the parent. Markedly, a classification of disorganized attachment is a risk factor for later development. 

See Attachment Styles for more on this concept and research

Attachment Theory Measurements

There is several dozen tools for measuring attachment types. Mary Main co-authored one of the more popular tools is the Adult Attachment Interview (AAI). Uniform assessment tools has allowed for thousands of studies, comparing the impacts of one attachment style to the other styles in ailments such as depression, abuse, or happy relationships. Some of these studies are informative.

Associated Concepts

• Still Face Experiment: This experiment involved instructing a mother to maintain a neutral facial expression and unresponsive demeanor while interacting with her infant, simulating a ‘still face’ devoid of emotional expression.
• Attachment Styles: Ainsworth’s research expanded on Bowlby’s work by identifying different attachment styles (secure, anxious, avoidant, and disorganized) based on the quality of early caregiving experiences.
• Object Relations Theory: This theory also deals with mental representations of self and others, emphasizing the importance of early family interactions in the development of the psyche.
• Harlow’s Rhesus Monkey Experiments: Using rhesus monkeys, Harlow investigated the effects of maternal deprivation by separating infant monkeys from their mothers. He observed the monkeys behavior to varying degrees of social isolation.
• Lorenz’s Imprinting Theory: This concept introduced by ethologist Konrad Lorenz, refers to the rapid and relatively permanent learning process that occurs during a brief critical period in early life. This phenomenon involves the attachment of a young animal to a specific individual or object, usually the parent. Imprinting is common among birds and some mammals.

A Few Words by Psychology Fanatic

In conclusion, attachment theory offers a profound understanding of human development and interpersonal dynamics. It reminds us that the bonds we form early in life shape our emotional landscape and influence our relationships well into adulthood. As we navigate the complexities of connection and separation, we must appreciate the invisible threads that tether us to our past and guide our future interactions. Whether secure or anxious, avoidant or disorganized, our attachment styles are not our destiny.

With awareness and effort, we can foster healthier attachments that lead to more fulfilling and emotionally resilient lives. Let us carry forward the legacy of Bowlby and Ainsworth by continuing to explore the rich tapestry of human attachment and by nurturing the relationships that sustain us.

Last Update: January 24, 2026

Resources:

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Mooney, Carol Garhart (2009). Theories of Attachment: An Introduction to Bowlby, Ainsworth, Gerber, Brazelton, Kennell, and Klaus. Redleaf Press; Illustrated edition. ISBN: 9781933653389
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Murphy, T. Franklin (2018) Anxious Lovers. Psychology Fanatic. Published: 12-7-2018; Accessed: 7-15-2022. Website: https://psychologyfanatic.com/anxious-lovers/
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Murphy, T. Franklin (2022). Secure Base. Psychology Fanatic. Published: 7-11-2022; Accessed: 7-12-2022. Website: https://psychologyfanatic.com/secure-base/
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Murphy, T. Franklin (2022a). Dyadic Regulation: Tapping into the Power of Mutual Support. Psychology Fanatic. Published: 5-26-2022; Accessed: 1-25-2026. Website: https://psychologyfanatic.com/dyadic-regulation/
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Murphy, T. Franklin (2022b). How Internal Working Models Shape our Future Relationships. Published: 8-16-2022; Accessed: 1-25-2026. Website: https://psychologyfanatic.com/internal-working-models/
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