Attachment Theory: History, Research, & Psychology​

By Kelsey Schultz, Ph.D. Candidate
​Reviewed by Tchiki Davis, M.A., Ph.D.
Our relationships with others are among the most important aspects of our existence. Keep reading to learn how we develop our style of relating.​
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The way we attach to other people is unique to each relationship. Some people might make us feel loved and secure whereas others might make us feel like we aren’t enough and that we need to work for their attention. Though the details of our relationships can be as varied as the relationships themselves, there are some common factors that may help us understand why we feel the ways we do about those that we are in relationships with.​
These common factors and the ways in which they influence how we relate to others are described by attachment theory. Let’s talk more about attachment theory and the predictions we might make about our own lives based on this theory.​
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What Is Attachment Theory? (A Definition)​

Attachment theory is a framework that was proposed to explain the origin of our various relationship styles, otherwise known as attachment styles (Levy et al., 2011). In other words, attachment theory seeks to explain why some of us feel anxious or fearful in a relationship whereas others feel secure and accepted.

According to attachment theory, our attachment styles begin to develop when we are infants and continue to be influenced by our experiences in early childhood (Bowlby & Ainsworth, 2013). The central premise of the theory is that our early experiences with our primary caregivers teach us what we can expect from others. That is, if our caregivers are patient and attentive, we will likely grow up expecting others to behave similarly. On the other hand, if our caregivers are volatile and unreliable, that is the behavior we will likely anticipate from others.

Attachment behaviors are seen as evolutionarily adaptive mechanisms that enhance an individual's chances of survival and well-being by promoting proximity to a protective and nurturing caregiver. In other words, we learn what we need to do to survive in the environment in which we find ourselves. If we need to learn to fend for ourselves as children, we do that. If we learn that we need to behave in a particular manner to receive affection from our caregivers, that’s what we will do.​

Attachment Theory and John Bowlby​

Attachment theory was originally developed by British psychologist, psychiatrist, and psychoanalyst John Bowlby (Sable, 2004). Early in his career, during the second world war, Bowlby worked with children who had been evacuated from London and were separated from their caregivers. This gave him the opportunity to study the impact of separation on the children’s behavior. Through this research, Bowlby began developing his hypotheses about the importance of attachment on development.

His research and theories have had a profound impact on the fields of psychology, child development, and psychotherapy. Bowlby's work revolutionized the way we understand the emotional bonds formed between children and their caregivers.​

Attachment Theory and Mary Ainsworth

Mary Ainsworth was a Canadian-American developmental psychologist who made significant contributions to the field of attachment theory, particularly through her work on the assessment of attachment patterns in infants and young children (Bretherton, 2003). She is best known for developing the Strange Situation procedure, which became a pivotal tool in identifying and categorizing different attachment styles in infants.

The Strange Situation paradigm allowed Ainsworth to observe a child’s response to being left by their caregiver for a short period of time while a stranger was in the room (Ainsworth, 1989). 

The procedure essentially goes like this:
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  • First, a caregiver (usually a mother) plays with their child in an unfamiliar room for a few minutes.
  • Then, a stranger enters the room and plays with/talks to the caregiver and the child.
  • Next, the caregiver leaves the room and the child is left alone with the stranger. If the child expresses distress in this context, the stranger attempts to comfort them. After a few minutes the stranger also leaves the room and the child is left entirely alone.
  • The stranger then reenters the room and again tries comforting the distressed child.
  • Finally, the caregiver comes back and the stranger leaves. 

Ainsworth was able to use the child’s response to their caregiver and to the stranger to identify their attachment style. Specifically, she determined that their reactions reflected one of three different attachment styles: ambivalent, avoidant, and secure.
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  • Children who were inconsolable when their caregiver finally reentered the room were identified as having an ambivalent attachment style.
  • Those who were unaffected by their caregiver’s return were classified as having an avoidant attachment style.
  • Children who were comforted when their caregiver returned were classified as having a secure attachment style.

Her work extended Bowlby’s attachment theory and provided a systematic method for other researchers to also explore attachment styles.​

Attachment Theory in Psychology

Attachment theory has remained an important part of psychological research for more than 50 years. Over this time, it has been widely studied and has been found to have applications in various fields, including developmental psychology, clinical psychology, education, and counseling. Though it is not without its criticism (Harlow, 2021), it offers a useful framework through which professionals can understand how early relationships shape an individual's emotional development. It also provides insights into addressing relationship difficulties and promoting healthy attachments through clinical interventions.​

Attachment Theory and Attachment Styles

The current model of attachment theory proposes four primary attachment styles. These include secure, anxious, avoidant, and disorganized (Fearon & Roisman, 2017). Let’s take a look at each attachment style in a little more depth.

Secure attachment: Children with secure attachment feel comfortable exploring their environment because they know their caregiver will be available to meet their needs. They display distress when separated but are easily comforted upon the caregiver's return. As adults, those with secure attachment tend to have healthier relationships and more positive self-esteem.

Anxious (or ambivalent) attachment: Children with anxious attachment tend to be overly concerned about their caregiver's availability. They often feel anxious and uncertain about the caregiver's responsiveness and might appear clingy or needy. In adult relationships, individuals with anxious attachment may exhibit high levels of insecurity and seek constant reassurance.

Avoidant attachment: Children with avoidant attachment learn to suppress their emotional needs and increase independence due to inconsistent caregiver responsiveness. They appear self-reliant and might avoid seeking comfort when distressed. In adulthood, avoidant attachment can lead to difficulty in forming close emotional bonds and a preference for emotional distance in relationships.
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Disorganized attachment: This style was later identified by Mary Main and others. Children with disorganized attachment exhibit confusing or contradictory behaviors, often as a result of experiencing inconsistent caregiving and even abusive or frightening behavior. These individuals can struggle with emotion regulation and interpersonal relationships as adults.

Attachment Theory and Relationships​

Early on in its development, attachment theory centered primarily around child development and the relationship between child and parent. In later years, however, attachment theory has been applied to other kinds of interpersonal relationships such as friendships and romantic relationships (Thompson et al., 2022).

Attachment Theory and Parenting

As mentioned previously, attachment theory suggests that attachment styles are formed throughout childhood, meaning that parenting plays a big role. While there is no generally agreed upon “best” parenting style, it is well documented that parents who are attentive and emotionally available tend to raise children with a secure attachment style.

History of Attachment Theory

As mentioned previously, the development of attachment theory began early in Bowlby’s career working with children who had been separated from their caregivers when they were evacuated from London (Sable, 2004). He found that children who had experienced prolonged separation were more likely to express delinquent behaviors (such as stealing) than were children who did not experience separation. This finding was the foundation for his maternal deprivation hypothesis, which stated that a lack of emotional bonds and a lack of consistent caregiving during early childhood could lead to long-term emotional and behavioral issues.​

In the 1950s and ’60s, Bowlby shifted his focus from maternal deprivation to the broader concept of attachment as an innate and biologically driven system. He hypothesized that attachment behaviors are universal and serve an evolutionary purpose.

This hypothesis was further developed with the help of Mary Ainsworth through the Strange Situation procedure we discussed earlier. Ainsworth's research using the Strange Situation led to the identification of different attachment styles, including secure, anxious-ambivalent, and avoidant. This research provided insights into how different caregiving experiences could shape attachment patterns.

Building on the foundation laid by Bowlby and Ainsworth, researchers have extended attachment theory to adult romantic relationships (Hazan & Shaver, 1990). They proposed that attachment patterns established in childhood could influence how individuals form and maintain intimate relationships in adulthood, leading to the development of attachment theory in adult relationships.

Attachment theory has continued to be a major focus of research across various disciplines including psychology, sociology, and neuroscience. Researchers have explored topics such as the impact of attachment on mental health, the intergenerational transmission of attachment patterns, and cross-cultural variations in attachment.

Key Concepts of Attachment Theory

Attachment theory has evolved significantly since it was originally formulated. The current attachment theory model includes several key concepts. Let’s briefly review some of these important aspects of attachment theory.

​​Attachment Patterns
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Attachment theory categorizes individuals into different attachment patterns based on how they respond to separations and reunions with caregivers. These patterns include secure, anxious-ambivalent, avoidant, and disorganized. These patterns are believed to reflect an individual's learned expectations about the availability and responsiveness of caregivers in times of need.

Early Relationships

Attachment theory emphasizes the critical importance of early relationships, especially with caregivers, in shaping an individual's emotional and psychological development. Secure attachments are associated with the provision of consistent care and emotional support, allowing children to develop a sense of trust and security.

Emotional Regulation

Secure attachments help children develop effective emotional regulation skills, which are vital for managing stress, anxiety, and other emotions throughout life. The caregiver serves as a secure base from which the child can explore the world and to which they can return for comfort and reassurance.

Impact on Later Relationships

Attachment patterns formed in childhood can influence an individual's interpersonal relationships including romantic relationships, friendships, and interactions with authority figures. Individuals with secure attachment tend to have more positive and fulfilling relationships, while insecure attachment styles can lead to relationship difficulties.

​​Continuity Across the Lifespan

While attachment patterns are established in early childhood, they can persist into adulthood. However, attachment is not fixed; individuals can develop more secure attachment styles through positive experiences and therapeutic interventions.

Neurobiological Basis

Attachment experiences have been shown to influence brain development and neural circuitry, particularly in regions associated with emotion regulation and social processing.  

Research on Attachment Theory

Attachment theory is still an important focus of psychological research today. Much of the recent work has focused on four central questions (Fearon & Roisman, 2017):
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  1. What role does the environment play in variation of attachment styles in early life? Does the evidence suggest that the environment explains more of the variation than genetics or general sensitivity?  
  2. Is there evidence for intergenerational transfer of attachment styles? In other words, are patterns of attachment passed down from one generation to the next?
  3. Are attachment styles stable across the lifespan? For example, do children with an insecure attachment style tend to become adults with an insecure attachment style?
  4. ​Is there a causal relationship between attachment styles and socio-emotional development and adjustment, or the ability to function well in society?

Research guided by these main questions encompasses a broad range of topics and applications including romantic relationships in adulthood, psychopathology, policy surrounding divorce and custody, training for foster parents, and optimizing the school environment (Thompson et al., 2022; Harlow, 2021).

Articles Related to Attachment Theory

​Want to learn more? Check out these articles:

Books Related to Attachment Theory

If you’d like to keep learning more, here are a few books that you might be interested in.

Final Thoughts on Attachment Theory​

Attachment theory is a framework for understanding how the relationship between a caregiver and a child shapes the structure and processes of the child’s mind and influences their behavior and relational styles throughout adulthood. This theory began as a means to understand the impact of separation from caregivers on a child’s behavior, and it has evolved over the past several decades to be useful for many different areas of psychological research and clinical practice. For more on attachment theory, check out this video:​

Video: The Attachment Theory: How Childhood Affects Life​

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