Synonyms

Infant mortality (as opposed to)

Definition

Human infants are very vulnerable and dependent on their caregivers for survival into reproductive age. The attachment system, as defined by John Bowlby, is a behavioral control system with a set goal of maintaining proximity to caregivers, which has been retained through evolution as it increased the chances of survival against predators and other natural dangers (i.e., the functional consequence). Bowlby also argued that caregivers have a complementary caregiving system making them responsive to children’s attachment behaviors. Thus, although children (the weaker part) attach to their caregiver(s) (the stronger part), and not the other way around, children’s forming of attachment is a collaborative effort. Mary Ainsworth subsequently discovered three organized patterns of attachment (i.e., secure, insecure-avoidant, and insecure-ambivalent/resistant), which have all been argued to be evolutionarily adaptive in that they enable children to adapt to their particular local environments and thereby increase chances of survival.

Introduction

Human children are born very vulnerable and are thus dependent on their caregiver(s) support in order to survive into reproductive age. Indeed, the proportional amount of time that human children are dependent on their caregivers is largely unparalleled in other species. Behavior systems enabling children to take an active part in affecting their caregiver’s caregiving behaviors therefore constitute an evolutionary advantage. Universally, human infants are also seen to form strong bonds – attachments – to their caregivers, seeking to maintain proximity to and protesting separations from their caregivers and using them as a reference point, a secure base, from which to explore the environment. John Bowlby, a child psychiatrist and psychoanalyst, sought to understand the nature of children’s ties – attachments – to their caregivers; why do children form attachments to their caregivers, and what is the function of attachment? The specific function of attachment according to Bowlby – increasing chances of survival by means of proximity to caregivers – is discussed below.

Infant Survival by Means of Maintaining Proximity to Caregivers

Bowlby could not accept the theories of attachment available at the time, since they deemed attachment secondary to processes such as feeding and/or other motivational processes (i.e., drives). Bowlby (1997/1982) deemed these theories unscientific and contrary to evidence and therefore sought an alternative explanation for attachment as a primary motivation in itself (see “Psychodynamic Foundations”). He came to draw from multiple sources, including his own experiences working as a child therapist, clinical research he had done on children with externalizing behavior problems (e.g., Bowlby 1944), scientific collaborations in which he examined effects of early child-caregiver separations (e.g., Robertson and Bowlby 1952), and research and theory from multiple scientific disciplines (see “John Bowlby: Pioneer of Attachment Theory”).

Bowlby became particularly influenced by ethology, cybernetics, and cognitive psychology (see “Evolutionary Foundations of the Attachment System and Its Functions”). Bowlby argued, following Darwin (1859) and the theory of natural selection, that humans (like all other animals) should be endowed with behavioral systems that whence evolved have been retained in evolution because they have been associated with adaptive functions in our ancestral species-typical environments. He consequently argued that we must search for an adaptive function of attachment in our environment(s) of evolutionary adaptedness (EEA), which have provided the pertinent selection pressures for an attachment behavioral system to develop. With the words of Bowlby, “Just as Darwin found it impossible to understand the structure of an orchid flower until he knew what insects flourished and visited it…, so, it is held, it is impossible to understand man’s instinctive behavior until we know something of the environment in which it evolved” (Bowlby 1997/1982, p. 61). Bowlby argued that ethology was the best present-day application of Darwin’s theories to behavioral systems in animals, drew heavily from ethology, and argued that the human attachment system should have prototypes in other animals. Bowlby also found that imprinting in birds and attachment behavior in other primates bear notable similarities to attachment behaviors in human children, which he argued may stem from convergent selection pressures as other animals have faced the same survival-related threats from predators (see “Evolutionary Foundations to the Attachment System and Its Functions”).

More specifically, Bowlby argued that the attachment system must have been retained due to it serving the specific function of increasing the chances of survival. Bowlby argued that in humans’ primeval environment and ecological niche, humans were living as nomads in small hunter-gatherer societies, in environments comparable to that of other large ground-living species of higher primates. A key characteristic of our ancestral environments, according to Bowlby, was a risk of falling prey to predators and other natural dangers. Thus, he argued a behavioral system that monitors the whereabouts of and promotes the maintenance of proximity to caregiver(s) should have served an important function that increased the chances of survival. Indeed, Bowlby argued that proximity to caregivers is the predictable outcome of activation of the attachment system, which has served an adaptive function in reducing the risk of falling victim to predators and other natural dangers (i.e., the functional consequence); “Because immature organisms are usually very vulnerable they are commonly endowed with behavioral equipment that produces behaviors specifically likely to minimize risk, e.g. behavior that maintains proximity to a parent” (Bowlby 1997/ 1982, p. 143).

Children are thought to be endowed with attachment behaviors and prepared to form attachments to caregivers who are continuously present and responding to their signals. Attachment behaviors, which are triggered by internal (e.g., sickness, pain) and external (e.g., separations from caregiver, strangers) cues of danger, include all behaviors that children use to maintain and increase proximity to their caregivers, and they are thus defined by their function, with increasing development expanding the repertoire (see “Individual Variations in Attachment”). Attachment behaviors are often grouped into three broad classes of behaviors: aversive signaling behaviors (e.g., crying, screaming), positive signaling behaviors (e.g., smiling, vocalizing), and active behaviors (e.g., following, clinging). Terminating signals, which decreases the activation of the attachment system, includes signals conveying that there is no more cause of alarm. For young children this typically pertains to close physical proximity to the caregiver whereas older children can often be soothed by other means. Importantly, children’s attachment relationships are hierarchical; children (the smaller, weaker part) form attachments to their caregivers (the stronger, wiser part), not the other way around. Bowlby however also argued that caregivers are endowed with a caregiving system that typically makes them biased and responsive toward their children’s signals, for example, retrieving children following signs of danger. Children’s forming of attachment is therefore a collaborative effort.

Bowlby’s close collaborator Mary Ainsworth (Ainsworth et al. 1978) and Mary Main (Main and Solomon 1986) subsequently discovered specific categories of individual variations in attachment security and organization, corresponding to particular patterns of caregiver sensitivity in relation to their children’s signals (see “Individual Variations in Attachment”). These categories are (currently) secure attachment (see “Secure Attachment”), insecure-avoidant attachment and insecure-ambivalent/resistant attachment (see “Insecure-Organized (Anxious and Avoidant) Attachment”), and disorganized attachment (see “Disorganized Attachment and Reactive Attachment Disorder”). From a developmental psychology perspective, secure attachment is typically regarded as the optimal way of organizing one’s attachment behaviors, with the insecure patterns judged suboptimal due to their links to increased risk for maladaptive development (see “Effects of Attachment Quality and Organization”). All three organized patterns of attachment (i.e., secure, insecure-avoidant, insecure-resistant/ambivalent) have however been discussed in evolutionary terms as adaptive ways of organizing attachment behaviors so as to maintain as much proximity as possible in relation to the caregiver(s) and thereby aiding survival, with no organized pattern of attachment inherently superior to any other one (Main 1981; Simpson and Belsky 2008). Indeed, Bowlby argued that the attachment behavioral system is open to learning so as to function adaptively in children’s particular environments. Avoidant attachment (minimizing expressions of vulnerability in relation to a caregiver that has previously rebuffed the child’s bids for proximity) may thus constitute an adaptive way of ensuring some level of proximity to the caregiver without risking further rejection and potential abandonment. Similarly, ambivalent/resistant attachment (showing high levels of negative affect and maximizing attention toward a caregiver that has previously been inconsistently sensitive) may constitute an adaptive strategy for not being overlooked in the presence of danger.

Bowlby was very specific that the set goal of attachment is the maintenance of proximity to caregivers due to caregiver proximity facilitating protection against predators (and other natural dangers). Bowlby discarded a hypothesis that attachment facilitates learning skills necessary for survival from caregivers with the argument that the biological function of a behavioral system cannot be any favorable outcome its performance may have; “Biological function is defined more narrowly: it is that consequence that in course of evolution has led the behavior in question to become incorporated into the biological equipment of a species” (Bowlby 1997/1982, p.224). Hence, he argued that a specific advantage in terms of survival and reproduction must be conferred by the behavior, leading the individuals who display it to achieve higher rates of survival and reproduction (i.e., leaving more progeny). As rhetorically asked by Bowlby (1997/1982): if attachment serves a function of facilitating learning, why does attachment persist into adulthood, when critical learning is complete? (see also “Attachment in Adulthood”).

In support of his argument, Bowlby noted that observations of many species of animals indicate that an isolated animal is more likely to be attacked by predators. Attachment behaviors are moreover elicited particularly easily in animals which “by reason of age, size, or condition, are especially vulnerable to predators, for example the young, pregnant females, the sick” (1997/1982, p.226). Attachment behaviors also tend to always be elicited at high intensity when an animal is alarmed (e.g., in danger). Bowlby also noted that the finding that young offspring attach even to caregivers who are hurtful and frightening to the offspring is hard to explain by any other theory.

In a possible critique of Bowlby’s position, he also argued, however, that variations in the quality of children’s attachments to their caregivers are of substantial importance for their personality development. He argued that children construct cognitive-affective internal working models (IWMs) from attachment-related experiences with the caregiver(s) that whence constructed will influence perceptions and expectations of the self and others and thereby how we will behave in relation to others (Bowlby 1997/1982). Although this may be regarded as a secondary side effect of variations in attachment security and organization, not a primary functional consequence in itself, it does raise the possibility that attachment has functions beyond immediate survival against predators, such as learning skills to function adaptively in one’s broader social group. Indeed, Main and Hesse (1992) argue that the attachment behavioral system likely serves multiple survival functions, including protection from unfavorable temperature changes and attacks by conspecifics. Relatedly, although Bowlby was right in arguing that attachment is not secondary to feeding, proximity to caregivers also increases chances of getting fed as well as learning what is edible (Harlow and Zimmerman 1959). Current research is also examining the importance of attachment for adult functioning, such as for reproductive strategies, with some findings indicating that attachment security and organization may affect onset of puberty (Simpson and Belsky 2008).

Conclusion

Children’s attachments and attachment behaviors are the result of an attachment behavioral control system that continuously monitors the whereabouts of the caregiver(s) and has the maintenance of proximity to caregivers as a set goal. This system, which bears similarities to imprinting in birds and attachment in other primates, has been retained in evolution as it, according to Bowlby, has served a specific function of increasing survival against predators and other natural dangers. The attachment system is moderately open to learning, and children develop different patterns of attachment in relation to their caregivers depending on the caregiver’s pattern of responding to the child’s signals, with all organized patterns argued to be evolutionarily adaptive in maintaining proximity to the caregiver in children’s specific environments.

Cross-References