Attachment theory suggests that babies need to build a strong relationship with at least one main caregiver to stay safe and grow into emotionally and socially healthy individuals. This idea was first introduced by psychiatrist and mental health expert John Bowlby (1907–90). The theory explains that secure relationships form when caregivers are kind, attentive, and consistently present, especially between six months and two years of age. As children grow, they use these close relationships as a safe foundation to explore the world and return to for comfort. Research suggests that how children interact with caregivers helps create a type of mental picture—called an internal working model—that affects how they behave in future relationships. Feeling anxious or sad when separated from a caregiver is considered a normal and helpful reaction for a securely attached child.
In the 1970s, developmental psychologist Mary Ainsworth expanded Bowlby’s work, explaining that caregivers must be available, responsive, and able to understand a baby’s needs. She and her team created a method called the Strange Situation Procedure to observe how babies react to being separated from and reunited with their caregivers. This process helped identify different attachment styles: secure, avoidant, anxious, and later, disorganized. In the 1980s, the theory was applied to adult relationships, showing its relevance beyond early childhood. Bowlby’s theory combined ideas from fields like evolutionary biology, object relations theory, control systems theory, ethology, and cognitive psychology. His work was most clearly explained in his book series Attachment and Loss (1969–82).
Although some experts criticized the theory when it was first introduced in the 1950s, it has since become a major way to study early social development and has led to much research. Some researchers, like Michael Lamb and his team in the 1980s, found that tests like the Strange Situation Procedure mainly reflect what happens in the environment around the child and caregiver, not just the child’s behavior. Other studies question the theory’s claims about how attachment works universally across cultures, the role of a child’s personality in forming attachments, the difficulty of observing internal working models, and the usefulness of labeling attachment styles. Supporters of the theory often do not address these challenges. Despite this, the theory’s main ideas continue to influence therapy, social policies, and childcare practices. Recent research shows that the theory is incorrect in assuming that a single caregiver (usually a mother) has the most important role in shaping a child’s social behavior. Instead, the theory overemphasizes the influence of mothers while ignoring the roles of genetics, differences between cultures, and larger social factors.
Attachment
Attachment theory describes the emotional bond between a person and an attachment figure, such as a parent or caregiver. These bonds often form between a child and caregiver, as children naturally seek safety, security, and protection. While attachment theory explains many aspects of relationships, it does not fully explain all human connections. For example, Ainsworth suggested that attachment might be similar to love, but not all relationships between a baby and others are based on love.
In relationships between a child and an adult, the child’s bond is called "attachment," and the adult’s response is called the "caregiving bond." The child’s attachment is thought to be created by a system in the child called the "attachment behavioral system" (ABS), while the adult’s caregiving bond is linked to the adult’s "caregiving behavioral system." The theory suggests that children are born with a natural tendency to form attachments with caregivers, as this helps them survive and feel safe.
The bond between a child and their attachment figure is especially important during times of danger or stress, especially when no other caregivers are nearby. Having at least one supportive attachment figure is vital during a child’s early years. In addition to support, a caregiver must be able to understand and connect emotionally with the child. If a caregiver and child are not well attuned, the child may feel lonely or anxious.
Attachment theory suggests that infants can form attachments with any caregiver who is consistently present and responsive. The quality of the relationship matters more than the amount of time spent together. In families where parents have traditional roles, the mother is often the main attachment figure, but anyone who acts in a caring way can become a primary attachment figure. A secure bond with a father, even if he is a secondary attachment figure, may help reduce the negative effects of a poor relationship with the mother.
"Alarm" refers to when the ABS is activated by fear. "Anxiety" is the fear of being separated from the attachment figure. If the attachment figure is not available or unresponsive, the child may feel upset or distressed. In infants, being separated for a long time can cause fear, anger, sadness, and despair. However, once the ABS is fully developed (by age 3 or 4), long separations no longer threaten the child’s bond. Older children and adults may feel insecure due to long absences, poor communication, or signs of rejection.
Modern attachment theory is based on three ideas:
1. People naturally want close, one-on-one relationships.
2. Managing emotions and fear helps people stay healthy.
3. Attachment helps people grow and adapt.
Bowlby believed that attachment behaviors evolved because they helped infants survive. He noted that some animals, like primates, form strong bonds with caregivers. However, he did not fully consider how different species care for their young. He thought that close, one-on-one bonds, like those seen in gorillas and chimpanzees, were important for survival. He mistakenly believed that early human societies also relied on such bonds.
Over time, social species develop behaviors that help individuals and groups survive. Bowlby’s theory focused on the child’s ability to seek closeness to caregivers, rather than the role of other adults in protecting the child. He imagined early humans always staying close to their mothers, but this view ignored the role of other caregivers in many societies. Bowlby argued that children evolved the ability to sense danger, such as being alone or encountering strangers, which led them to seek closeness to a caregiver.
Bowlby believed that the child’s first strong relationship was unique to humans, calling this idea "monotropy." He thought children formed the strongest bonds with a single caregiver. However, many children have multiple important relationships with people who care for them. In some cultures, children are raised by many family members, a possibility Bowlby did not consider. Today, researchers no longer believe that one relationship is fundamentally different from others, instead suggesting that children develop a hierarchy of relationships.
As research has shown that not all children display the same attachment behaviors or fear strangers, the theory now focuses more on how early experiences with caregivers shape a child’s internal system of thoughts, feelings, and beliefs about themselves and others. This system, called the "internal working model of social relationships," is thought to develop over time and influence how people interact with others. While this model is still being studied, it is seen as a key part of attachment theory.
Empirical research and theoretical developments
The basic materials for the formation of a baby's attachment behavioral system include a small number of inborn behaviors that help babies stay close to caregivers. These behaviors, called attachment behaviors by John Bowlby, were influenced by the study of animal behavior. Bowlby believed that the attachment behaviors babies showed in their early months, such as smiling, crying, looking, and sucking, were fixed action patterns (FAPs).
Fixed action patterns were first studied in animals like stickleback fish and digger wasps. These behaviors are automatically triggered by a specific signal and remain the same, even if the situation changes. Bowlby thought this meant that young babies’ smiles, cries, looks, and sucking were "very similar each time" and "continued in the same way no matter what happened around them."
Researchers later found that babies’ early behaviors, such as smiling, looking, reaching, sucking, crying, and babbling, were not fixed. These behaviors change slightly depending on the situation and serve many purposes. For example, a baby’s cries vary in length, loudness, and how continuous they are. Even the youngest babies smile differently in intensity, direction, and how long they last. Looking and babbling are also flexible behaviors that change based on the baby’s needs.
Because these behaviors change from birth, they cannot be signals that evolved only to help babies stay close to their mothers, as Bowlby claimed. However, they can act like signals if they help caregivers respond to the baby’s needs. This is part of what attachment theorists call the caregiving behavioral system.
John Bowlby first thought that infant attachments could be directly observed. He believed that behaviors like smiling, fear of strangers, and separation anxiety were visible signs of attachment. Based on this, Mary Ainsworth and her team created a lab-based method called the Strange Situation Procedure (SSP) to measure how babies attached to their mothers. They expected babies to use their mothers as a secure base to explore a room and return to her when scared.
However, their research showed that this was not always true. After a mother left her baby with a stranger, only one out of ten babies followed her, and only one out of five cried. Many babies did not change their behavior when the mother left. Ainsworth concluded that separation anxiety and fear of strangers were not as common as Bowlby’s theory suggested. She also found that attachment behaviors did not form a system as Bowlby described, and these behaviors could not be used to diagnose a baby’s attachment to a caregiver.
To keep Bowlby’s theory, Ainsworth and her team changed their view. They proposed that attachments are internal structures inside the baby that are not easily linked to observable behaviors. This shift led to a new way of studying attachment, where only experts trained in attachment theory can classify the type of attachment between a baby and caregiver.
The SSP is still the most common method for diagnosing secure or insecure attachment and testing new methods like the Attachment Q-sort. It takes 21 minutes. Over time, researchers have questioned whether SSP results show the current state of a baby’s relationship with their caregiver, which might change over days or months. Others wonder if SSP classifications measure a stable, long-term attachment as attachment theory suggests.
Psychological tests are reliable if they give the same results under similar conditions. If the SSP is reliable, it should classify a baby’s attachment the same way when tested twice, weeks or months apart. Studies show that SSP results are most reliable when a baby’s family background, such as income, education, social support, housing, and childcare, remains the same between tests. If a baby’s family background changes, the SSP results are likely to change too. SSP classifications are especially unstable when researchers study babies from families that are not middle-class or whose parents did not volunteer to participate.
A key finding is that studies that do not control for a family’s background might incorrectly link attachment security to factors like maternal sensitivity. This is because both security and sensitivity could be influenced by other factors, like social support, which is often not studied. Social support strongly affects caregiving behavior in all families, whether they are high or low risk.
Most attachment studies compare different factors, but some try to prove that maternal behavior directly causes a baby’s attachment security by improving caregiving. However, these studies cannot be trusted if they do not control for placebo effects, where babies might change their behavior simply because they think something is happening.
In conclusion, as Michael Lamb and his team found in the 1980s, attachment classifications from the SSP do not mainly show an internal system or working model in babies. Instead, they are more likely to reflect recent events in the baby’s environment, such as changes in the family or caregiver.
Attachment patterns
A child who feels securely attached to a parent will explore and play freely while the parent is nearby, using the parent as a "secure base" for exploration. The child will interact with strangers when the parent is present, may become upset when the parent leaves, and will be happy to see the parent return. The child feels confident that the parent will be available and will respond to their needs.
Children with anxious-ambivalent attachment, also called "resistant attachment," show a form of insecure attachment. These children may feel distressed even before the parent leaves and may be difficult to comfort when the parent returns. Some may show signs of anger (C1 subtype), while others may appear helpless or passive (C2 subtype). Researchers have noted that this type of attachment is not fully understood, and its connection to disorganized attachment remains unclear. However, it is believed that this attachment style develops in response to caregiving that is unpredictable. The child’s anger or helplessness during reunion may be a way to ensure the caregiver stays close.
Children with anxious-avoidant attachment tend to avoid or ignore the caregiver, showing little emotion when the caregiver leaves or returns. These children may not explore much, even when the caregiver is present. In the 1980s, researchers were puzzled by this group because these children did not show distress when separated from the caregiver. Some ignored the caregiver upon return (A1 subtype), while others approached but then turned away (A2 subtype). Later studies found that their calm behavior might hide feelings of sadness, as shown by their heart rates.
In 1983, a new classification system was introduced by Crittenden and others, including a fourth type called "disorganized." This classification was added by Mary Main, a colleague of Ainsworth. In the Strange Situation test, disorganized behavior occurs when an infant’s actions seem confused or uncoordinated, such as showing fear, moving in strange ways, or appearing frozen. Some disorganized infants still seek comfort from the caregiver and stop showing distress, even without clear signs of anxiety or avoidance.
Reactive attachment disorder (RAD) is a mental health condition that is different from disorganized attachment. It is a recognized diagnosis (ICD-10 F94.1/2 and DSM-IV-TR 313.89) and involves significant problems in forming relationships, usually beginning before age five, linked to severe neglect or abuse.
The dynamic-maturational model (DMM) explains how attachment relationships affect development and behavior. It focuses on relationships between children and parents, as well as between parents themselves. The model was created by Patricia McKinsey Crittenden and her team.
Studies on early attachment and later social skills often do not account for social background factors, such as family income or education. For example, research has shown that mothers who display more withdrawing behavior during the Strange Situation test are more likely to have their children referred for help, but the social backgrounds of these children are rarely studied. Similar issues affect claims about securely attached children having better peer relationships.
Some research suggests that babies as young as six months old can interact with peers, even before forming strong attachments to caregivers. This raises questions about whether early social experiences in groups, such as in extended families, might influence the development of attachments.
Most studies that ignore social background factors fail to show a clear link between early experiences and long-term social skills. However, when these factors are not considered, early experiences may seem to influence how children view relationships later in life, which could affect their future relationships and behavior.
Changes in attachment during childhood and adolescence
Attachment theory suggests that during childhood and adolescence, people develop an internal working model that helps them form relationships. This model is thought to influence how a person thinks about relationships, which forms as they experience attachments during childhood and adolescence. The way this model is organized is generally believed to lead to more stable relationships in people who develop it, compared to those who rely only on their own thoughts when making new connections. As people grow older, their thinking skills improve, and their ongoing social experiences help make the internal working model more complex.
Changes in attachment during childhood and adolescence show both growth and consistency over time. Research indicates that children's attachment security can increase or decrease based on their ongoing social interactions, not just the care they receive from adults.
Cultural differences
In many Western cultures, children often form a strong bond with one caregiver, usually their mother. This is called a dyadic model, but it is not the only way to create a secure and emotionally healthy child. Even with a single caregiver who is attentive and caring, a child's future success is not guaranteed. Studies from Israel, the Netherlands, and East Africa show that children with multiple caregivers can feel secure and may develop better abilities to understand different viewpoints. This is especially common in hunter-gatherer communities, such as those in rural Tanzania.
In these communities, mothers may care for their children, but their role differs from that of stay-at-home mothers in Western cultures. For example, some Australian Aboriginal languages do not have a specific word for "mother," instead using the term "aunt." This reflects a cultural practice where many adults, not just the mother, help care for children. These adults, called allomothers, share the responsibility of raising children. While mothers are important, they are not the only source of care and security. Many group members, including those without blood ties, help raise children, creating multiple relationships and attachments. Evidence of this communal parenting has been found throughout history and may have influenced how humans developed multiple attachments.
In rural India, families often include three or more generations, such as great-grandparents, grandparents, parents, and children. In these families, children may have four to six caregivers to choose from as their favorite attachment figure. Uncles and aunts, who are the parents' siblings and their spouses, play an important role in supporting the child's and mother's emotional and social development.
Even in Western and Western-influenced cultures, differences in child-rearing practices have been observed. A study comparing 60 Japanese mother-infant pairs to Ainsworth's findings showed that Japanese children who were insecurely attached were mostly resistant, with no avoidant children. This may be due to Japanese child-rearing practices that emphasize close mother-infant bonds more than in Western cultures. A study in Northern Germany found different attachment patterns among 46 mother-infant pairs compared to North America, with 52% of infants classified as avoidant, 34% secure, and 13% resistant.
All children need a safe and supportive environment with strong relationships to develop healthily. However, the types of relationships and social environments available vary globally. These may involve one parent or often include aunts, uncles, grandparents, cousins, siblings, and friends. According to attachment theory, children in Western societies might appear to need only one type of relationship for healthy development. However, cross-cultural research shows that many different approaches can lead to successful adulthood worldwide.
Attachment styles in adults
In the late 1980s, Cindy Hazan and Phillip Shaver applied attachment theory to adult romantic relationships. Researchers have identified four main adult attachment styles: secure, anxious-preoccupied, dismissive-avoidant, and fearful-avoidant. These styles are similar to those seen in infants: secure, insecure-ambivalent, insecure-avoidant, and disorganized/disoriented. Adult attachment styles influence how people feel and handle their emotions. Recent studies show that insecure attachment styles are linked to lower emotional intelligence and lower ability to be mindful. Further research shows that having consistent support from caring and responsive partners can improve attachment security and help people become more mentally strong over time.
History
After World War II, a new way of thinking about parenting spread in Western countries. This approach focused on the needs of children. Benjamin Spock's book, The Common Sense Book of Baby and Child Care, published in 1946, became one of the most popular books of the 20th century. Earlier experts had told parents not to comfort babies when they cried or feed them whenever they wanted. Instead, they advised feeding babies every four hours and letting them cry until they stopped. Spock disagreed. He believed this was unkind. His book encouraged parents to be flexible and treat each child as unique. He emphasized that using common sense and showing love were the most important parts of raising children. A similar change in thinking also happened in post-war Britain.
After writing Maternal Care and Mental Health, John Bowlby wanted to learn more from other scientific fields, such as evolutionary biology, ethology, developmental psychology, cognitive science, and control systems theory. He proposed that the emotional bond between an infant and their caregiver was not learned but developed naturally due to evolutionary reasons. Bowlby aimed to create a theory based on scientific observations, not Freudian ideas. He believed his attachment theory corrected the lack of clear explanations in Maternal Care and Mental Health.
Bowlby studied psychoanalysis under Melanie Klein, who was part of the object relations theory school. Unlike Freud’s idea that infants are born with a strong focus on themselves that makes social relationships impossible, object relations theory suggests babies form emotional connections with their mothers from birth, even if these connections are influenced by imagination. This belief in the importance of the infant-mother relationship from the start of life shaped Bowlby’s work and is central to attachment theory.
Bowlby learned from ethology, the study of animal behavior, that observing animals in their natural environments helps build scientific theories. He stressed the importance of using observable actions of babies, rather than relying on psychoanalytic interpretations of their imagined experiences. In the early 1950s, Bowlby read Konrad Lorenz’s work on ethology and borrowed ideas like fixed action patterns, instincts, and behavioral systems. He also used ethology to highlight how human social behavior, especially in infants, has evolutionary roots.
At first, Bowlby used ethological ideas about imprinting and critical periods in his theory. He was inspired by Konrad Lorenz’s research on how baby birds form attachments to their parents. Bowlby suggested there was a time, from six weeks to twelve months, when babies form attachments most easily. Later research showed that human attachment behaviors differ from bird imprinting, so this comparison was no longer used.
The theory of control systems, known as cybernetics, influenced Bowlby. He compared a child’s need to stay close to a caregiver with the need to explore, explaining this balance as similar to how the body keeps things like blood pressure stable. The distance a child keeps from a caregiver changes based on their needs. For example, a child might move closer to a caregiver if a stranger appears or if they are hurt. The child’s goal is not to reach the caregiver but to maintain a comfortable distance depending on the situation.
Bowlby’s use of Piaget’s theory of cognitive development raised questions about object permanence, the ability to remember objects that are not visible. Infants seemed to recognize strangers and react to their mother’s absence earlier than Piaget’s theory suggested was possible. Today, advances in understanding mental representation allow for more detailed explanations of these behaviors than were available during Bowlby’s time.
Bowlby discovered the concept of the internal working model in the work of John Zachary Young, a scientist who studied how animals remember things. Young was influenced by the philosopher Kenneth Craik.
Neurobiology of attachment
In addition to studies that track people over time, scientists have also studied how the brain and body work together in attachment. Researchers now look at how the brain develops, genetic influences on behavior, and personality traits. Usually, personality traits and attachment are separate areas of development, but both can affect how people interact with others and themselves. Some personality traits might make certain people more likely to struggle with stressful or difficult relationships with caregivers early in life. When caregivers are not available or do not respond to a child’s needs, some children may be more likely to develop problems with attachment.
Social factors, such as a family’s background, can influence the quality of care a child receives during infancy and childhood. These factors may be linked to differences in how the brain regulates stress. In studies about attachment, scientists mainly focus on two areas: automatic body responses, like heart rate or breathing, and the activity of the hypothalamic–pituitary–adrenal axis, a system that helps the body manage stress. Scientists have measured babies’ physical reactions during the Strange Situation procedure, which looks at differences in how babies respond to five simple social behaviors. Some recent research suggests that early attachment relationships may be stored in a child’s cells at the molecular level, which can affect how the immune system works later in life. Other studies show that early negative experiences (not necessarily related to attachment) may change the immune system in ways that could increase the risk of health problems like heart disease, autoimmune disorders, or certain cancers.
New discoveries about brain structures, nerve pathways, and chemical systems in the brain have made it possible to explore how the brain might be involved in how people form attachments (internal working models), if these can be clearly defined. Early evidence shows that caregiving and attachment involve both unique and shared areas of the brain. Another area of study is how genes inherited from parents influence attachment. For example, a specific variation in the gene that makes the D2 dopamine receptor has been linked to anxious attachment, and a variation in the gene for the 5-HT2A serotonin receptor has been linked to avoidant attachment.
Studies show that how people attach to others in adulthood is connected to signs in the body that relate to the immune system. For example, people with an avoidant attachment style may produce more of a substance called interleukin-6 (IL-6) when facing social stress, while those with an anxious attachment style often have higher levels of cortisol (a stress hormone) and fewer T cells (a type of immune cell). Although children differ genetically and may need different types of attachment relationships, research consistently shows that warmth from a mother during infancy and childhood helps build a safe environment, leading to better immune system function. One idea is that it makes sense biologically for children to have different responses to how they are raised.
The most recent and detailed model explaining how the brain is involved in attachment is called the functional neuro-anatomical model of human attachment (NAMA), created by Pascal Vrticka and others. This model has also been expanded to include disorganized or disrupted attachment (NAMDA). A detailed explanation of how brain circuits are involved in attachment is also available. Recent research from the field of social neuroscience highlights the importance of how the brain and body work together in relationships, which is studied under the field of relational neuroscience.
Crime
Attachment theory is often used in the study of crime. It helps researchers understand why people commit crimes, how different types of crimes happen, and how to create policies that might stop crimes before they occur. Studies show that problems in the relationship between children and their caregivers early in life can increase the chance that someone will commit crimes later. In this area, attachment theory is considered "perhaps the most influential of modern psychological theories about crime."
Two theories explain why crime often increases during late teenage years and early adulthood. These are the developmental theory and the life-course theory, both of which use ideas from attachment theory. Developmental theory suggests that people who had troubled relationships as children may continue to have problems with the law as adults. Life-course theory suggests that relationships at any stage of life can affect whether someone is more likely to commit crimes.
Troubled relationships in childhood can increase the risk of domestic violence. These early problems can prevent people from forming healthy ways to handle stress. Without good coping skills, people may act violently as adults. According to Bowlby’s theory, children who feel their caregivers are not meeting their needs may show anger to get attention. Feeling unsupported by a partner has been linked to increased chances of men committing violence. Other factors include feeling loved less by a parent as a child and low self-confidence. People with a dismissive attachment style, often seen in those who act antisocially or narcissistically, may be emotionally abusive and violent. People with a borderline or emotionally dependent style, which comes from unstable childhood relationships, often have high levels of anger.
Studies show that people who commit sexual crimes often had less secure relationships with their parents as children compared to those who do not commit crimes. This suggests that early problems with attachment can last into adulthood. In one study, 57% of sexual offenders had a preoccupied attachment style. Research also shows that different types of sexual crimes may be linked to different attachment styles. People with a dismissive style may be more likely to commit violent crimes against adult women. In contrast, those who abuse children are more likely to have a preoccupied style, as their need for approval can lead to unhealthy, sexualized relationships.
Attachment theory is especially important in probation settings. Probation officers try to learn about a person’s early relationships because this can help them understand how the person might react to challenges and when they might be more likely to break the law again. One way to use this theory is for probation officers to act as a "secure base" for the person they are helping. This means being dependable, safe, and understanding, which can help the person develop a healthier relationship with someone they can trust.
Practical applications
Attachment theory, which explains how people develop emotionally and socially, has been used in social policies that affect children’s care, mental health, and well-being. Research shows that children with insecure attachment styles often struggle with managing emotions and may develop unhealthy ways to cope, which can impact mental health treatment over time.
Bowlby, the creator of attachment theory, was inspired by social policies related to child care. Applying attachment ideas to real-world policies and practices is challenging. In 2008, C.H. Zeanah and others noted that supporting strong early relationships between children and parents is a growing focus for mental health workers, service providers, and policymakers. The National Institute of Child Health and Human Development (NICHD) once believed that high-quality day care should help children form secure attachments.
However, child care policies are debated, and recent studies show that focusing on keeping infants closely connected to one caregiver is difficult in most Western group-based child care settings. Challenges include the need for caregivers to balance attention among many children, part-time work schedules, and high staff turnover. These factors make it hard to build strong one-on-one relationships. Some experts argue that group-based care, like in Japan, may be more effective than strict one-on-one care. Despite criticisms of attachment theory, some policymakers still support training child care workers in attachment theory and requiring higher education and better pay for these roles.
Attachment theory also influences decisions about work arrangements, such as parental leave. Advocates argue that limited leave can harm early parent-child bonding. Historically, attachment theory was used to guide care for hospitalized or institutionalized children and those in poor-quality day care. Today, historians say this view is outdated, as attachment theory is now part of a broader movement focused on child-centered care.
Some attachment advocates believe that non-maternal care, especially in group settings, harms children’s social development. However, research does not support this view. Poor-quality care is risky, but children in good-quality group settings often thrive.
Attachment theory affects decisions in legal and social work settings, such as foster care placements. In the past, psychoanalysis was the main framework for such cases, but attachment theory has replaced it in many places. Courts now focus on the quality of caregiver relationships rather than automatically favoring biological parents. In the UK, recent rulings show that courts no longer assume contact with both parents is always best for children.
Attachment theory also helps social workers and courts decide on placements for children in foster care. However, the theory’s assumptions about family structures and traditional gender roles can lead to unethical decisions. Still, considering a child’s attachment needs often influences how safe different placement options are seen to be.
Despite criticism, attachment theory remains a widely studied theory of emotional and social development. It has generated much research but has been less used in clinical practice. This may be due to limited focus on applying the theory in practice by Bowlby and other researchers, as well as confusion about the term “attachment” among professionals. Some people mistakenly link attachment theory to unscientific treatments like “attachment therapy.” The theory’s narrow assumptions about family life may also limit its use.
In 1988, Bowlby wrote about how attachment theory could help treat family and child problems. He focused on helping parents improve their relationships with their children and with therapists. Modern programs use this theory to help children of all ages, from infants to older children, through therapy, public health efforts, and training for foster caregivers. These programs often assess a child’s attachment status and a caregiver’s responses, as attachment involves both the child’s behavior and the caregiver’s actions. Some programs target foster care because children with attachment challenges may not get the support they need from caregivers. These programs have shown success.
Attachment-based therapists believe the theory helps understand how people function and can improve therapy. Some adult psychotherapy approaches, like relational psychoanalysis, also use attachment theory to guide treatment.
Criticism
John Bowlby strongly supported the idea that attachment theory is a scientific theory, as described by Karl Popper. This means the theory could be proven wrong if any of its predictions based on observations were shown to be incorrect. Mary Ainsworth and her colleagues disagreed:
Many of Bowlby’s predictions based on observations have been shown to be incorrect by later research. However, the most recent edition of The Handbook of Attachment states that "nothing from the thousands of studies over the past 40 years has seriously challenged the core ideas of the theory since Bowlby’s time." This supports Ainsworth’s argument that attachment theory is not a scientific theory but a type of social movement, as described by Thomas Kuhn, that influences how people understand knowledge. Despite this, many people, including attachment supporters, developmental psychologists, and policy-makers, still claim the theory is scientific. Developmental psychologist Suzanne Zeedyk explains that today, when people refer to attachment theory, "that statement is no longer regarded as 'theory.' The operation of the attachment system is now regarded as 'fact.'"
The attachment perspective attracts scientists and non-scientists because it focuses on children’s needs in discussions about development. Some attachment supporters claim that child-centered parenting styles are directly linked to Bowlby’s theory. However, child-centered parenting was popularized before Bowlby developed his theory. Overestimating Bowlby’s influence has become common in the attachment movement, which often praises him as if he were a hero. For example, British psychoanalyst Professor Brett Kahr states that Bowlby’s findings are now "beyond all doubt," and as a result:
People who promote attachment theory often praise well-known attachment theorists highly. For example, Peter Fonagy and his colleagues say attachment theory is based on "the detailed and careful observations of Mary Ainsworth," and that the idea of internal working models has been supported by "some of the greatest minds in the attachment field."
There is a strong "in-group" and "out-group" dynamic within attachment advocacy. People who support the theory often do not notice its scientific problems until they leave the group. Judi Mesman observed that scientists who work within the attachment theory group often ignore or criticize research that challenges the theory. For example, Michael Lamb and his colleagues published research in the 1980s that questioned the attachment perspective. However, their findings are not mentioned in the latest edition of The Handbook of Attachment, and Lamb’s colleagues have "effectively ostracized" him.
Bowlby aimed to replace psychoanalysts’ interpretations of young children’s thoughts with observations of their behavior. However, attachment theory has moved away from studying young children’s natural behavior and now focuses on interpreting limited behaviors observed in the Strange Situation Procedure (SSP). These behaviors are used to suggest invisible mental models, but there is no widely accepted definition of these models.
Some specific observations made by Bowlby have been proven incorrect. For example, he claimed that attachment behaviors in young infants are fixed and not affected by their environment. However, research shows these behaviors change based on context. Bowlby also claimed that securely attached infants and toddlers usually show fear of strangers or separation anxiety when left with strangers. However, this is not typically observed. Additionally, attachment behaviors do not consistently form the same patterns of behavior seen in other animals.
Research by Mary Ainsworth and her colleagues, which formed the basis of the SSP, was not as detailed as attachment theorists claim. Marga Vicedo, who studied Ainsworth’s original records, found that the SSP’s results are not stable, especially when the social situations of infants and their families change between tests. Studies show that SSP results are most reliable when a family’s social background, such as their economic status, marriage, and childcare, remains the same between tests. However, when these factors change, SSP classifications often change as well. This is especially true when researchers study infants from families that are not middle-class or whose parents did not volunteer to participate.
An important result of this is that studies that do not control for a family’s social background may produce misleading results. For example, a study might suggest that secure attachment is linked to a mother’s sensitivity, but this link could actually be caused by other factors from the family’s background. This means that results from studies claiming long-term effects of attachment classifications cannot be trusted if they do not control for these background factors. The results may appear stronger than they are because other factors are not studied.
In short, classifications of attachment security from the SSP do not primarily reflect a child’s internal mental system. Instead, they likely reflect recent changes in the child’s social environment.
The most well-known long-term studies that examined how early attachment affects adult development have not found the results predicted by attachment theory. This is especially true in studies that account for changes in a child’s background during development. For example, a study in Minnesota found that, when background factors were properly considered, attachment security in infancy explained only 5% of the differences in social skills when the children were 19 years old. Two studies in Germany also found no strong link between early attachment security (measured by the SSP) and social skills later in life. Long-term research in Israel found that stable attachment representations were linked to a stable caregiver environment, and unstable representations were linked to unstable environments.
Overall, these findings show that when studies using the SSP include measures of a child’s social circumstances, there may be a connection to adult outcomes. However, this connection is likely due to the child’s environment, not the attachment system itself.