Attachment Theory: Bowlby and Ainsworth’s Theory Explained

Key Takeaways

  • Attachment is defined as a “lasting psychological connectedness between human beings” (Bowlby, 1969, P. 194), and may be considered interchangeable with concepts such as “affectional bond” and “emotional bond.”
  • A person’s first attachment is often established with the primary caregiver during infancy. However, it must be noted that attachment is not unique to infant-caregiver relationships but may also be present in other forms of social relationships.
  • Attachments of various kinds are formed through the repeated act of “attachment behaviors” or “attachment transactions,” a continuing process of seeking and maintaining a certain level of proximity to another specified individual (Bowlby, 1969).
  • Because caregivers vary in their levels of sensitivity and responsiveness, not all infants attach to caregivers in the same way.

Understanding Attachment

Attachment theory in psychology originates with the seminal work of John Bowlby (1958).  In the 1930s John Bowlby worked as a psychiatrist in a Child Guidance Clinic in London, where he treated many emotionally disturbed children.

This experience led Bowlby to consider the importance of the child’s relationship with their mother in terms of their social, emotional and cognitive development.  Specifically, it shaped his belief about the link between early infant separations with the mother and later maladjustment, and led Bowlby to formulate his attachment theory.

Bowlby (1958) proposed that attachment can be understood within an evolutionary context in that the caregiver provides safety and security for the infant. Attachment is adaptive as it enhances the infant’s chance of survival.

Children come into the world biologically pre-programmed to form attachments with others, because this will help them to survive.

This is illustrated in the work of Lorenz (1935) and Harlow (1958).  According to Bowlby, infants have a universal need to seek proximity with their caregiver when stressed or threatened (Prior & Glaser, 2006).

The Importance of Early Emotional Bonds

  • Attachment can be defined as a deep and enduring emotional bond between two people in which each seeks closeness and feels more secure when in the presence of the attachment figure.
  • Attachment behavior in adults toward the child includes responding sensitively and appropriately to the child’s needs.  Such behavior appears universal across cultures.
  • Attachment theory explains how the parent-child relationship emerges and influences subsequent development.
  • Attachments are most likely to form with those who responded accurately to the baby’s signals, not the person they spent more time with. Schaffer and Emerson called this sensitive responsiveness.
  • Attachment is characterized by specific behaviors in children, such as seeking proximity to the attachment figure when upset or threatened (Bowlby, 1969).

Ainsworth’s Strange Situation”

Mary Ainsworth and her colleagues discovered three major patterns that infants attach to their primary caregivers (“mother figures”) from their Strange Situation Procedure (Ainsworth et al., 1978).

The study recruited four different samples of infants at around one year of age, and engaged them in the Strange Situation procedure, roughly described below:

An infant was put into an unfamiliar environment with his or her mother and was free to explore the environment; a stranger entered the room and gradually approached the infant; the mother then left the room, returning after the infant spent some time alone with the stranger.

Ainsworth and colleagues observed how comfortable each infant was physically farther away from the mother in an unfamiliar environment, how each infant interacted with the stranger, and how each infant greeted the mother upon her return.

Based on the observations, they sorted the infants into three groups: secure, anxious, and avoidant.

Attachment Styles

Attachment styles refer to the particular way in which an individual relates to other people. The style of attachment is formed at the very beginning of life, and once established, it is a style that stays with you and plays out today in how you relate in intimate relationships and in how you parent your children.

The concept involves one’s confidence in the availability of the attachment figure for use as a secure base from which one can freely explore the world when not in distress and a safe haven from which one can seek support, protection, and comfort in times of distress.

Secure Attachment

Bowlby (1988) described secure attachment as the capacity to connect well and securely in relationships with others while also having the capacity for autonomous action as situationally appropriate.

Secure attachment is characterized by trust, an adaptive response to being abandoned, and the belief that one is worthy of love.

An infant with a secure attachment is characterized as actively seeking and maintaining proximity with the mother, especially during the reunion episode. The infant may or may not be friendly with the stranger, but always showed more interest in interacting with the mother.

Additionally, during the same situation the infant tended to be slightly distressed during separation from the mother, but the infant rarely cried.

Ainsworth and colleagues interpreted infants who were securely attached to their mothers, showed less anxiousness and more positive attitudes toward the relationship, and were likely because they believe in their mothers’ responsiveness towards their needs.

Anxious (Ambivalent) Attachment

Anxious attachment (also called ambivalent) relationships are characterized by a concern that others will not reciprocate one’s desire for intimacy. This is

caused when an infant learns that their caregiver or parent is unreliable and does not consistently provide responsive care towards their needs.

An anxiously attached infant is characterized as being somewhat ambivalent (and resistant) to the mother. The infant often demonstrated signs of resisting interactions with the mother, especially during the strange situation reunion episode.

However, once contact with the mother was gained, the infant also showed strong intentions to maintain such contact. Overall, ambivalent infants often seemed to display maladaptive behaviors throughout the Strange Situation.

Ainsworth and colleagues found ambivalent infants to be anxious and unconfident about their mothers’ responsiveness, and their mothers were observed to lack “the fine sense of timing” in responding to the infants’ needs.

As adults, those with an anxious preoccupied attachment style are overly concerned with the uncertainty of a relationship. They hold a negative working model of self and a positive working model of others.

Avoidant Attachment

Children with avoidant attachment styles tend to avoid interaction with the caregiver, and show no distress during separation. This may be because the parent has ignored attempts to be intimate, and the child may internalize the belief that they cannot depend on this or any other relationship.

An infant with an avoidant attachment was characterized as displaying little to no tendency of seeking proximity with the mother.

The infant often showed no distress during separation with the mother, interacted with the stranger similarly to how he or she would interact with the mother, and showed slight signs of avoidance (turning away, avoiding eye contact, etc.) when reunited with the mother.

Ainsworth and colleagues interpreted infants’ avoidance behaviors as a defensive mechanism against the mothers’ own rejecting behaviors, such as being uncomfortable with physical contact or being more easily angered by the infants.

Disorganized (Fearful) Attachment

Main and Solomon (1986) discovered that a sizable proportion of infants did not fit into secure, anxious, or avoidant, based on their behaviors in the Strange Situation experiment. They categorized these infants as having a disorganized attachment type.

Disorganized attachment is classified by children who display sequences of behaviors that lack readily observable goals or intentions, including obviously contradictory behaviors or stilling/freezing of movements.

Main and Solomon found that the parents of disorganized infants often had unresolved attachment-related traumas, which caused the parents to display either frightened or frightening behaviors, resulting in the disorganized infants being confused or forcing them to rely on someone they were afraid of at the same time.

Stages of Attachment

Rudolph Schaffer and Peggy Emerson (1964) investigated if attachment develops through a series of stages, by studying 60 babies at monthly intervals for the first 18 months of life (this is known as a longitudinal study).

The children were all studied in their own home, and a regular pattern was identified in the development of attachment.

The babies were visited monthly for approximately one year, their interactions with their carers were observed, and carers were interviewed.

A diary was kept by the mother to examine the evidence for the development of attachment. Three measures were recorded:

Stranger Anxiety – response to arrival of a stranger.

Separation Anxiety – distress level when separated from carer, degree of comfort needed on return.

Social Referencing – degree that child looks at carer to check how they should respond to something new (secure base).

They discovered that baby’s attachments develop in the following sequence:

Very young infants are asocial in that many kinds of stimuli, both social and non-social, produce a favorable reaction, such as a smile.

Indiscriminate Attachments (6 weeks to 7 months)

Infants indiscriminately enjoy human company, and most babies respond equally to any caregiver. They get upset when an individual ceases to interact with them.

From 3 months infants smile more at familiar faces and can be easily comfortable by a regular caregiver.

Specific Attachment (7 – 9 months)

Special preference for a single attachment figure.  The baby looks to particular people for security, comfort, and protection.  It shows fear of strangers (stranger fear) and unhappiness when separated from a special person (separation anxiety).

Some babies show stranger fear and separation anxiety much more frequently and intensely than others, nevertheless, they are seen as evidence that the baby has formed an attachment.  This has usually developed by one year of age.

Multiple Attachment (10 months and onwards)

Many of the babies from the Schaffer and Emerson study had multiple attachments by 10 months old, including attachments to mothers, fathers, grandparents, siblings and neighbors.

The baby becomes increasingly independent and forms several attachments. By 18 months the majority of infants have formed multiple attachments.

The multiple attachments formed by most infants vary in their strength and importance to the infant. Attachments are often structured in a hierarchy, whereby an infant may have formed three attachments but one may be stronger than the other two, and one may be the weakest.

The results of the study indicated that attachments were most likely to form with those who responded accurately to the baby’s signals, not the person they spent more time with.  Schaffer and Emerson called this sensitive responsiveness.

Intensely attached infants had mothers who responded quickly to their demands and, interacted with their child. Infants who were weakly attached had mothers who failed to interact.

The Lasting Impact of Early Attachment

According to Bowlby’s theory (1988) when we form our primary attachment we also make a mental representation of what a relationship is (internal working model) which we then use for all other relationships in the future i.e. friendships, working and romantic relationships.

The different attachment styles may be viewed essentially as different internal working models of “relationships” that evolved out of event experiences (Main, Kaplan, & Cassidy, 1985).

internal working model of attachment

This would suggest that early interactions with caregivers could not only shape how an infant understood and behaved in relationships (as exemplified by infant attachment styles), but that such impact could be carried forward into adult attachment .

According to Bowlby (1969) later relationships are likely to be a continuation of early attachment styles (secure and insecure) because the behavior of the infant’s primary attachment figure promotes an internal working model of relationships which leads the infant to expect the same in later relationships.

In other words, there will be continuity between early attachment experiences and later relationships. This is known as the continuity hypothesis.

In humans, attachment does not conclude in infancy, or even childhood, but instead is active throughout the lifespan, with individuals gaining comfort from both physical and mental representations of significant others (Bowlby, 1969).

It is through an individual’s internal working model that childhood patterns of attachment are carried forward across the life cycle into adolescent and adulthood.

The notion of security is still an important one; however, the growing emergence of autonomy is also significant as the attachment system in adults is less likely to be activated due to them being able to tolerate higher levels of distress compared to children.

During adulthood, new attachment bonds are formed which may become a significant source of support during periods of distress, or during periods of goal achievement and exploration

Researchers have proposed that working models are interconnected within a complex hierarchical structure (Bowlby, 1980; Bretherton, 1985, 1990; Collins & Read, 1994; Main, Kaplan, & Cassidy, 1985).

complex hierarchical structure of attachment relationships

For example, the highest level model comprises beliefs and expectations across all types of relationship, and lower level models hold general rules about specific relations, such as romantic or parental, underpinned by models specific to events within a relationship with a single person.

The existence of multiple mental models is supported by evidence which demonstrates considerable within-person variability in the expectations and beliefs that people hold about the self and others (Baldwin & Fehr, 1995).

Furthermore, although specific models of attachment relationships are positively associated with more overarching general working models, the correlations are small to moderate (less than .40), indicating that they comprised distinct beliefs regarding the self and significant others (Cozzarelli, Hoekstra, & Bylsma, 2000).

Likely, general mental models indicate a typical appraisal of the self and others across relationships, and relationship-specific beliefs about the self and one’s partner would plausibly represent only a part of these generalized beliefs.


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Olivia Guy-Evans

BSc (Hons), Psychology, MSc, Psychology of Education

Associate Editor for Simply Psychology

Olivia Guy-Evans is a writer and associate editor for Simply Psychology. She has previously worked in healthcare and educational sectors.

Saul Mcleod, PhD

Educator, Researcher

BSc (Hons) Psychology, MRes, PhD, University of Manchester

Saul Mcleod, Ph.D., is a qualified psychology teacher with over 18 years experience of working in further and higher education.