Attachment theory, in developmental psychology, the theory that humans are born with a need to form a close emotional bond with a caregiver and that such a bond will develop during the first six months of a child’s life if the caregiver is appropriately responsive. Developed by the British psychologist John Bowlby, the theory focused on the experience, expression, and regulation of emotions at both species (normative) and individual (person-specific) levels of analysis.

Bowlby believed that the attachment system, as he and others called it, served two primary functions: to protect vulnerable individuals from potential threats or harm and to regulate negative emotions following threatening or harmful events. The normative component of attachment theory identifies the stimuli and contexts that normally evoke and terminate different kinds of emotions, as well as the sequence of emotions usually experienced following certain relational events. The individual-difference component addresses how people’s personal histories of receiving care and support from attachment figures shape their goals, working models (i.e., interpersonal attitudes, expectations, and cognitive schemas), and coping strategies when emotion-eliciting events in relationships occur.

Normative Features Of Attachment Theory
Bowlby’s fascination with the emotional ties that bind humans to each other began with an astute observation. In all human cultures and indeed in primate species, young and vulnerable infants display a specific sequence of reactions following separation from their stronger, older, and wiser caregivers. Immediately following separation, infants protest vehemently, typically crying, screaming, or throwing temper tantrums as they search for their caregivers. Bowlby believed that vigorous protest during the early phases of caregiver absence is a good initial strategy to promote survival, especially in species born in a developmentally immature and very dependent state. Intense protests often draw the attention of caregivers to their infants, who would have been vulnerable to injury or predation during evolutionary history if left unattended.
If loud and persistent protests fail to get the caregiver’s attention, infants enter a second stage, known as despair, during which they usually stop moving and become silent. Bowlby believed that from an evolutionary standpoint, despondency is a good second strategy to promote survival. Excessive movement could result in accident or injury, and loud protests combined with movement might draw predators. According to this logic, if protests fail to retrieve the caregiver quickly, the next best survival strategy would be to avoid actions that might increase the risk of self-inflicted harm or predation.

After a period of despair, infants who are not reunited with their caregivers enter a third and final stage: detachment. During this phase, the infant begins to resume normal activity without the caregiver, gradually learning to behave in an independent and self-reliant manner. Bowlby believed that the function of emotional detachment is to allow the formation of new emotional bonds with new caregivers. He reasoned that emotional ties with previous caregivers must be relinquished before new bonds can fully be formed. In terms of evolution, detachment allows infants to cast off old ties and begin forming new ones with caregivers who might be able to provide the attention and resources needed for survival. Bowlby also conjectured that these normative stages and processes characterize reactions to prolonged or irrevocable separations in adult relationships, which might also have evolutionary adaptive value in terms of maintaining, casting aside, or forming new romantic pairings.

In addition to identifying the course and function of these three distinct stages, Bowlby also identified several normative behaviours that infants commonly display in attachment relationships. Such hallmark behaviours include sucking, clinging, crying, smiling, and following the caregiver, all of which serve to keep the infant or child in close physical proximity to the caregiver. Bowlby also documented unique features of caregivers and their interactions with the infant that are likely to promote attachment bonds. The features include the competence with which the caregiver alleviates the infant’s distress, the speed with which the caregiver responds to the infant, and the familiarity of the caregiver to the infant. These behaviours and features are also believed to be critical to the development of adult attachment relationships.

Individual-Difference Features Of Attachment Theory
Attachment theorists after Bowlby have proposed that different attachment patterns (in children) and attachment styles or orientations (in adults) reflect different ways of regulating affect (observable manifestations of emotion), particularly controlling or dampening negative affect in stressful, threatening, or particularly challenging situations. Individual differences in patterns of attachment in 12- to 18-month-old children were first documented by Mary Ainsworth and her colleagues using the Strange Situation. The Strange Situation involves a sequence of separations and reunions of caregivers (usually mothers) and their children. It assesses how children regulate negative emotions regarding their caregivers when the children are upset. Even though most children are distressed when left alone at this age, securely attached children tend to reduce their negative emotions by using their caregivers as a “secure base,” and they resume other activities fairly quickly after reuniting with them in the Strange Situation. “Anxious-resistant” children, by comparison, remain distressed and often exhibit anger or resentment toward their caregivers during reunion episodes. “Anxious-avoidant” children, who display fewer overt signs of distress but usually have elevated heart rates, remain distant and emotionally detached from their caregivers during reunions, opting to calm themselves in a self-reliant manner.

During later stages of development, one of the key differences between secure individuals and different types of insecure individuals is how their negative emotions are regulated and controlled based on their specific beliefs and expectations about the availability of comfort and support from their attachment figures. Highly secure individuals have learned from past caregiving experiences to follow “rules” that permit distress to be acknowledged and motivate them to turn toward attachment figures as sources of comfort and support. Highly avoidant adults, in contrast, have learned to follow rules that limit the acknowledgment of distress and encourage the use of self-reliant tactics to control and reduce negative affect when it arises. Highly anxious people have learned to use rules that direct their attention toward the possible source of distress, to ruminate about it, and to worry that their attachment figures will never fully meet their persistent needs for comfort and support.

Mario Mikulincer and others have proposed a process model that outlines the sequence of events that underlie the emotional coping and regulation strategies of people who have different attachment histories. For example, when stress or a potential threat is perceived, highly secure individuals remain confident that their attachment figures will be attentive, responsive, and available to meet their needs and help them lower their distress and anxiety. These beliefs, in turn, should increase their feeling of security, which should deactivate their attachment systems, allowing them to use constructive, problem-focused coping strategies that over time are likely to solve their problems.

Highly insecure individuals follow different pathways. When highly anxious individuals encounter attachment-relevant stress or threats, they are uncertain as to whether their attachment figures will be sufficiently attentive, available, and responsive to their needs. Such worries sustain their distress and keep their attachment systems activated, resulting in the use of emotion-focused coping strategies such as hypervigilance to signs of possible relationship loss and ruminating over worst-case scenarios. When highly avoidant individuals feel stressed or threatened, they experience—but may not consciously acknowledge—anxiety at a physiological level. To keep their attachment systems deactivated, highly avoidant persons work to inhibit and control their emotional reactions by using avoidant coping strategies.

These three emotion regulation and coping strategies—problem-focused, emotion-focused, and avoidance-focused strategies—are the source of many of the interesting cognitive and behavioral outcomes that have been discovered in people who have different attachment styles or orientations. More securely attached individuals, for instance, typically experience more intense and mild positive emotions in their romantic relationships and fewer intense and mild negative emotions, whereas the reverse is true of more insecurely attached persons. Longitudinal research has also documented connections between an individual’s early attachment pattern (being classified as secure or insecure in the Strange Situation at age one) in relation to the mother and emotions experienced and expressed with a romantic partner 20 years later. In addition, individuals classified as insecure (either anxious-avoidant or anxious-resistant) in the Strange Situation at age one are rated by their teachers as less socially competent during early elementary school. Lower social competence, in turn, predicts greater likelihood of being rated as insecurely attached to same-sex friends at age 16, which in turn predicts both the experience and expression of greater negative affect in relationships with romantic partners when individuals are in their early 20s. Thus, there are indirect but theoretically meaningful links between early attachment experiences and later attachment-based relationships in early adulthood, just as Bowlby anticipated.