Applied History of Psychology/Attachment
Attachment is defined as a social and emotional bond between infant and caregiver that spans both time and space (Carlson, Buskist, Enzle, & Heth, 2002).
Animal Studies that Influenced Attachment Theory and Research: Lorenz and Harlow 
The following summarizes animal research conducted by two influential people whose ideas shaped the way later researchers would conceptualize attachment in human beings; Konrad Lorenz’s (1903-1989) and Harry Frederick Harlow (1905-1981). In particular, researchers credited for founding the theory and research behind attachment, John Bowlby and Mary Ainsworth, considered the following research with animals to inform their own work with human beings.
In 1937, Konrad Lorenz conducted research with goslings, which supported ethological ideas of attachment. He observed the behaviour of newly born goslings, which would follow or ‘imprint’ on almost any moving object (e.g. mother, duck, or even human being) (Shaffer, Wood & Willoughby, 2002). Lorenz reported that imprinting was automatic and did not need to be taught, and that this behaviour occurs within a critical period after birth, and that gosling remain attached to the particular object (Shaffer, Wood & Willoughby, 2002). Lorenz explains:
- …goslings following responses become imprinted “to geese” or “to humans,” but it is still an intriguing puzzle which particular stimulus situation represents each of these concepts. The human-imprinted gosling will unequivocally refuse to follow a goose instead of a human, but it will not differentiate between a petite, slender young girl and a big old man with a beard (Lorenz, 1965)
Lorenz goes on to explain:
- During the first two days after leaving the nest, the gosling follows the parent about and there is a second tremendous increase in the selectivity of its following response. By that time, it has learned to recognize the parents personally and will never mistake another pair of geese for them… (Lorenz, 1965)
This idea of imprinting influenced Bowlby’s theory of attachment in humans. In 1956 he wrote about his support for the ecological view of attachment over the opposing and more popular views held by learning theorists and psychoanalysis:
- Two views are now current. One, which is held by all those of the learning theory school…held by many psychoanalysts…that the infant's only primary needs are the physiological ones for food, warmth and so on, and that, insofar as he becomes emotionally attached to his mother, it is because he learns that she is the agent through whom his physiological needs are satisfied...The alternative view is that the infant's need to attach himself to a mother-figure is as primary as his need to take nourishment or to prefer warmth to cold. This implies the existence of a primary socially-oriented drive, basically independent of the need for food or warmth. This view is held by the group of European students of animal behaviour headed by Lorenz and Tinbergen...Pending the results of this, it is the second hypothesis which seems to me the more likely to prove right. It is plain that the infant is endowed with at least two innate responses which have a social significance, namely crying and smiling… (Bowlby, 1956).
Mary Ainsworth who worked closely with Bowlby, admitted that Bowlby’s interest in an evolutionary and ethological approach to attachment initially made her “uneasy”, and that she had asked him to reconsider this theoretical position (Ainsworth, 1983). It was only after Ainsworth conducted the very first empirical study on attachment that she reconsidered this position.
Bowlby and Ainsworth’s ideas regarding attachment were also influenced and supported by research conducted by Harry Harlow in the late 1950’s. Harlow conducted many studies examining the effects of rhesus monkeys separated from their mothers at birth. His most popular study entailed examining the behaviour of infant monkeys who were raised by two surrogate mothers from birth; a “wire” mother and a “cloth” mother. This research demonstrated that regardless of which mother the monkeys received nourishment from they continually sought comfort and safety from the cloth constructed surrogate mother (Shaffer, Wood & Willoughby, 2002).
Of particular interest to Ainsworth, were Harlow’s findings regarding his monkey subjects behaviour in the presence of the cloth mother, in which he explains, “…it as if the cloth mother provides the infant with a sense of security, releasing positive responses of exploration and play…” (Harlow, 1961). Harlow’s findings supported Ainsworth’s own ideas regarding a caregiver’s role as a secure base for their infant.
This brief description of Konrad Lorenz’s and Harry Harlow’s animal research demonstrates their influence on attachment research and ideas that are still prominent today. In particular, ideas surrounding an infants need to form an attachment with their caregiver, and how that attachment influences subsequent development.
John Bowlby (1907-1990) 
Early Biographical History 
John Bowlby was born in 1907 in London, England to an upper-middle class family. His parents, especially his father, were described as “remote” and largely “inaccessible”, and his relationship with them was considered “distant” (Coates, 2004). The caregiving for Bowlby and his siblings was provided primarily by nannies, as this was custom among families of their class (referred to as haute bourgeoisie) and generation. Bowlby had two older sisters, and two brothers (one older and one younger). The elder brother, Anthony, (who was only 13 months older than Bowlby) was considered their mother’s clear favourite. He appeared gifted intellectually, became a successful industrialist and inherited their father’s name. John and Anthony were treated as twins – dressed in matching clothes and placed in the same classroom. Bowlby made attempts to overpower his brother, who remained determined to exert his advantage over his younger counterpart. Their younger brother, Jim, seemed to display possible intellectual limitations and struggled throughout his life. Bowlby’s competitiveness combined with his concern for disadvantaged children may have its roots in his position between his two brothers. Bowlby was quite protective of Jim, especially when he was bullied by their older brother. When this occurred, Bowlby was especially outraged over the apparent lack of sensitivity that Anthony displayed towards their younger brother (Brandell & Ringell, 2007).
Bowlby’s mother held the view that spoiling children was “dangerous”, and so she regularly blocked any attempts by the children to elicit attention and affection from her (van Dijken, 1997). Their mother had confided to friends that she never worried about her children and felt comfortable leaving them to their own devices. She received reports about her children from their nanny who was responsible for all daily care-taking duties (e.g., bathing, feeding, etc.). Their mother would “visit” with the children from 5 to 6 PM daily, after tea, where she would read to them (Holmes, 1993). She seemed to spend more time with her children during their summers, which were spent on the Isle of Skye.
As a preschooler, Bowlby shared a close relationship with his nanny who served as his primary caretaker. However, when he was almost four-years-old, she left the family. Bowlby would later write: “for a child to be looked after entirely by a loving nanny and then for her to leave when he is two or three, or even four or five, can be almost as tragic as the loss of a mother” (Bowlby, 1958, quoted in van Dijken, 1997, p. 25). At the age of eight, Bowlby was sent to a boarding school with his older brother, which coincided with their father being sent off to war. Bowlby has reported feeling very unhappy throughout his stay at the school. In later years, he told his wife that he would not send even a “dog” away from home at such a young age (Coates, 2004): “Unhappiness in a child accumulates because he sees no end to the dark tunnel. The thirteen weeks of a term might just as well be thirteen years” (Bowlby, 1973, p. 3, quoted in Coates, 2004, p. 574). These experiences appear to have shaped the development of Bowlby's ideas on the impact of parenting and early experiences on children. In particular, he loathed traditional English child-rearing patterns of the time, which emphasized the denial of love and affection to children so as not to spoil them.
Although he initially chose to study medicine at Cambridge, Bowlby became interested in working with children and left his studies after one year to volunteer at a small analytically-oriented residential institution for maladjusted and delinquent children. Bowlby came to view this experience as the single-most valuable learning opportunity in his life (van Dijken 1997). Bowlby was drawn to the plight of two children in particular. One of these children was an isolated, withdrawn child who was expelled from school due to theft. Bowlby wrote how this child had never experienced a stable relationship with a mother figure. The other child was a anxious boy who became quite attached to Bowlby and followed him around like a shadow. Both of these children had experienced the loss of their mother, and it is through working with them that Bowlby was sensitized to the effects of maternal deprivation on children's development and well-being (Karen, 1998). His experiences with these two boys would lead Bowlby to reconsider his career goals. Specifically, Bowlby would return to medical school but chose to train as a child psychiatrist. He subsequently attended the British Psychoanalytic clinic where he trained with Melanie Klein.
Through his training in psychoanalysis (and his experience with his own analyst), Bowlby came to view analysts (including Melanie Klein) as overly focused on the child’s inner fantasy life (e.g., conflicts between aggressive and libidinal drives) and overlooking actual events and experiences in the child’s real life. Bowlby argued for a greater emphasis on the role of interactions with parents in shaping a child’s personality, and speculated that the origins of these interactions were in the parents’ early experiences with their own parents.
In 1936, Bowlby began working at the London Child Guidance Clinic where he studied behaviour and emotional disturbances among children raised in institutions. He found that many of these children were largely "affectionless". In other words, they were unable to love because they had not formed a solid attachment to a mother figure early in life. Brandell and Ringell (2007) note that Bowlby's observations took place in England during World War II at a time when families were losing fathers who went to fight in the war. The family members who remained experienced tremendous financial difficulties, leading parents to abandon their infants to be raised in hospitals and institutions. Beginning in the late 1930’s, Bowlby would publish several papers on the effects of maternal separation and loss on children. Specifically, Bowlby argued that “psychological deprivation” (due to maternal deprivation) as a opposed to economic, nutritional, or medical deprivation was the primary source of maladjustment in children (Coates, 2004).
Maternal Deprivation 
The impact of maternal deprivation (through loss of the mother due to death or separation) on children was first outlined by John Bowlby in a series of studies published in the 1940’s and early 1950’s. Bowlby claimed that maternal deprivation produces disadvantageous physical, intellectual, behavioural, and emotional outcomes in the developing child. In “Child care and the Growth of Love” (1953), Bowlby presents his own studies of juvenile delinquents in addition to observations by others (including Anna Freud) of children raised in institutions and residential nurseries. He studies “the harm done” to these children using direct observations and through examining their early histories, referred to as retrospective studies. Based on these data, Bowlby concluded that children deprived of maternal care are likely to experience far-reaching disadvantages compared to children who are raised by their mothers. Specifically, children raised in institutions were found to display stunted physical development and delayed language development. As they grew older, their ability to form stable relationships with others was noticeably impaired. Based on his observations, Bowlby argued that “prolonged separation of a child from his mother (or mother substitute) during the first five years of life stands foremost among the causes of delinquent character development” (Bowlby, 1944, quoted in Holmes, 1993). Moreover, even brief separations during the first five years of life were considered by Bowlby to have detrimental implications for the child over the course of the lifespan. Bowlby's findings concerning the effects of maternal deprivation would form the basis of his pioneering contributions to attachment theory.
Contributions to Attachment Theory 
Bowlby is considered to have provided the most comprehensive and influential account of attachment formation. His contributions are heavily influenced by ethology, including an emphasis on the evolutionary origins and biological purposes of behaviour.
The young child, according to Bowlby, is “biologically biased” to develop attachments to its caretakers as a result of its genetic endowment. A close bond with the caretaker ensures survival, especially in times when the presence of a predator meant certain danger. Thus, the attachment bond is as important to the species as other inborn behaviour systems such as feeding and mating. In order for the infant to survive, he or she must be able to activate and maintain the parents’ proximity. These include attachment responses such as crying, clinging, and following. These are only effective if the parent reciprocates the child’s behaviour. Thus, a complimentary parental attachment system is believed to have developed over the course of evolution. Presently, attachment behaviour continues to be activated by perceived danger, and it is terminated by perceived safety. The biological function of attachment is the protection of the young, and the psychological function is to provide security. Thus, infants are “genetically wired” to maintain proximity to the mother and to signal to her for attention and help at times of distress. In turn, mothers are programmed to respond to such signals.
Bowlby also contributed the concept of internal working models. These begin to form as children become better able to represent the world to themselves in symbolic form (generally around 2 years old). They begin to form models of themselves, of significant others and of the relationships they have with others. These models eventually come to guide the child’s actions by helping the child anticipate another’s actions and plan an appropriate behavioural response. Internal working models are built up on the basis of experience with a particular attachment figure and reflect the quality of the relationship with that figure. The repeated experience of bonding with a warm, accepting mother contributes to the formation of an internal working model in which the child views the mother as a source of security and support. In turn, the child will expect the mother to be predictably available as a secure base and will develop positive emotions towards her. Such expectations are then likely to be transferred to other people. Once formed, the model is imposed like a template on new interactions. Moreover, the child’s model of the self is also largely built up through the first attachment relationship: a child who experienced a punitive and rejecting mother will develop a sense of failure and lack of self-worth. If the self is not acceptable in the eyes of the attachment figure, this will undermine the child’s own self-image. In the absence of sensitive and responsive caregiving, the child will come to view others as untrustworthy and the world as unsafe. Thus, working models of the self, others, and the world develop in unison.
Mary Ainsworth (1913-1999) 
Mary Ainsworth was born Mary Dinsmore Salter, on December 1st, 1913 in Glendale Ohio. Mary Ainsworth grew up and obtained all her formal education in Toronto, Ontario (Bretherton, 2003). Mary’s academic, professional, and personal decisions would continually lead her in the direction of attachment research. This direction would follow her into her seventy-sixth year when she completed her final empirical attachment study, and months before her death at the age of eighty-five, when she was honored by the APA for Lifetime Achievements in the Science of Psychology (Main, 1999).
In an autobiography, Mary explains that she first realized she wanted to become a psychologist in her last year of high-school, at 15-years-old. After reading Character and the Conduct of Life (1928) by William McDougall, Mary explains:
- It had not previously occurred to me that one might look within oneself for some explanation of how one felt and behaved, rather than feeling entirely at the mercy of external forces. What a vista that opened up! I decided thereupon to become a psychologist. (Ainsworth, 1983, p. 201)
Mary Ainsworth completed her undergraduate and graduate studies at the University of Toronto, in 1935 and 1939, respectively (American Psychological Foundation (APF), 1998). Mary’s doctoral dissertation was entitled “An Evaluation of Adjustment Based on the Concept of Security”, in which she is noted as stating, “Where family security is lacking, the individual is handicapped by lack of a secure base from which to work” (Main, 1999, p. 683). This experience set the stage for Mary’s later work in attachment, where the idea of an infant using their caregiver as a ‘secure base’ became a central component.
After completing her graduate work, Mary continued to work at the University of Toronto as a lecturer until 1942, when she was commissioned into the Canadian Women’s Army Corp (APF, 1999). Joining the Army was Mary’s choice, as she explains she was, “no longer content to be away from all the action …” (Ainsworth, 1983, p. 206). With this experience, Mary obtained expertise in clinical work, such as interviewing, history taking, and test administration (Bretherton, 2003). In 1946, she returned from her army work, and accepted a professor assistantship with the University of Toronto. Mary also co-directed a research team with her former doctoral supervisor, Dr. Blatz (Bretherton, 2003). It is within this research team that she met a graduate student, Leonard Ainsworth, who she married in 1950 (Bretherton, 2003).
The newly married couple decided to relocate to London, England, where Leonard would carry out his doctoral dissertation at University College. When Mary arrived in London she reconnected with a colleague she had met while in the Army, Edith Mercer, who directed her attention to a job advertisement in the London Times. This was a research position at Tavistock Clinic working with John Bowlby investigating the effects of maternal separation on infant personality development. Mary applied for this job, was interviewed and hired. Mary would later state that, “…Edith Mercer and a newspaper advertisement reset the whole direction of my research career” (Ainsworth, 1983, p. 208).
While working at Bowlby’s clinic Mary worked closely with James Robertson, who greatly influenced the way she would continue to collect data throughout her professional career. Robertson had previously trained under Anna Freud, and received thorough instruction on child observation, which included taking extensive narratives during naturalistic observation (Bretherton, 1992). Mary was impressed by Robertson’s methods, and would continue to emulate them in her own work.
In 1953 Mary and Leonard Ainsworth relocated to Uganda. It was here that Mary performed the very first empirical attachment study (1955-1956). This was a short term longitudinal naturalistic study in which Mary employed Robertson’s extensive recording methods. Mary concluded from this study that, “Attachment is not present at birth, but, however it emerges gradually…” (Ainsworth, 1967, p. 430). It was also during this study that Ainsworth revisited the ideas present in her dissertation regarding ‘secure base’, and started uncovering the crucial role of maternal sensitivity in infant attachment (Ainsworth, 1967; Bretherton, 2003).
Upon arriving in Baltimore (1955), Mary worked as a clinician, and a lecturer in clinical and developmental psychology at Johns Hopkins University. During this time, in 1960, Mary and Leonard divorced, she recounts this experience as a “personal disaster”, and explains that “a depressive reaction to divorce led me to seek professional help, which culminated into an eight-year psychoanalytic experience” (Ainsworth, 1983, p. 210). It was reported that through her experience in psychoanalysis she also became more ‘energized’ and ‘enthusiastic’ about her work, and therefore began to work more frequently (Main, 1999). Ainsworth herself claimed that psychoanalysis, “was the most important positive influence” on her career (Ainsworth, 1983, p. 210).
It was in Baltimore that Mary published her Uganda results, with encouragement from Bowlby. She also worked on a new empirical study to replicate her earlier findings. This study included extensive observations (72 hours per dyad) spanning over the period of the first 54 weeks of an infants life with their mother (Bretherton, 2003). It was during this time that Mary developed a lab procedure, which is still well known and still used to classify attachment in infants, the Strange Situation. Within this procedure, Mary witnessed unexpected behavioural patterns when examining reunions between infants and their mothers after brief separations. This procedure again made Mary re-examine the caregiver as a ‘secure base’ for infants. Support for her ideas and how to classify them within the strange situation were influenced by Harlow’s research with monkeys, in which his monkey subjects performed more exploratory behaviours in the presence of the ‘cloth mother’ versus a ‘wire mother’. She also developed the avoidant and ambivalent attachment classifications which are still well known today. In all, Mary was pleased with the Baltimore study, stating, “This research has turned out to be everything I had hoped it would be, and it has drawn together all the threads of my professional career” (Ainsworth, 1983, p. 211).
Findings lending support to Bowlby’s theories were influential in changing recommendations to existing parental practices, replacing ideas initially set out by learning theorist (Bretherton, 2003). Mary’s attachment research was highly controversial in the late 1970’s and therefore not always accepted. She was accused of being “out of touch with current changes in lifestyles” and not supporting women’s liberation; however she stated that her belief was that, “…infants are perhaps a million or so years out of touch with them [current lifestyle]” (Ainsworth, 1983, p. 213). In 1977, the Society for Research in Child and Development (SRCD) rejected a journal submission that summarized her work. It was not until other researchers began to replicate her work that she started to receive recognition (Bretherton, 2003). Indeed, SRCD, who had originally rejected her ideas, honored her with an ‘Award for Distinguished Contributions to Child Development’, in 1985 (Bretherton, 2003).
Aside from her contributions to attachment research, Mary is also well admired by many students that she mentored in this field. Ainsworth received the first ‘Mentoring Award’ of the APA’s Division of Developmental Psychology (Bretherton, 2003). She is also looked upon by current attachment researchers as a 'mentor' and 'hero'(Pederson & Pederson, personal communication, 2006). Her students remember her as a “lively and robust women” (Main, 1999, p. 682). Mary Ainsworth did not have any children of her own. She was known to refer to her graduate students as her family, in which she is quoted as stating, “The most extraordinary thing in my life has been seeing so many people become interested in the concept of attachment and dedicating themselves to developing it further…I think of them as my family” (Bretherton, 2003). In examining Mary Ainsworth’s life it is evident that she was devoted to developing and understanding infant-maternal interactions. Her work continues to influence current attachment research. The APA Gold Medal Award for Lifetime Achievement in the Science of Psychology in 1998 was ultimately to recognize her “as one of the major figures of the 20th century in the study of the relations between young children and their caregivers (E.Waters)” (Bretherton, 2003).
Strange Situation & Patterns of Attachment 
Stranger anxiety and separation anxiety are two infant behaviours in which attachment is revealed (Carlson et al., 2002). Stranger anxiety is a wariness and fearful response (i.e., crying and clinging to caregivers) that infants display when in the presence of an unfamiliar individual. This behaviour usually surfaces sometime between 6 months and 12 months of age. Separation anxiety is a fearful response (i.e., crying, arousal and clinging to caregivers) that infants exhibit when a caregiver attempts to leave the infant (Carlson et al., 2002). Separation anxiety first appears at around 6 months of age and peaks around 15 months of age. This pattern of development has been found across several cultures (Kagan, Kearsley, Zelazo, 1978). Stranger anxiety and separation anxiety are the bases for Ainsworth’s test of attachment called the Strange Situation.
The Strange Situation is a test of attachment involving an unfamiliar situation, people, and events developed by Ainsworth and her colleagues (Ainsworth, Blehar, Waters & Wall, 1978) in order to examine the balance of attachment and exploratory behaviours under conditions of high and low levels of stress. It involves a series of eight episodes, each lasting for approximately 3 minutes, during which an infant/child is exposed to events (i.e., separation anxiety and stranger anxiety) that are designed to elicit some distress related to attachment and security. It also allows the observation of the infants’ reactions to comforting by both the caregiver and stranger. The Strange Situation is based on the fact that if an infant has developed a secure attachment with his or her caregiver, then he or she will use the caregiver as a secure base from which to explore the unfamiliar environment. By evaluating the infant’s behaviours during the Strange Situation, researchers are able to determine the type of attachment between infant and caregiver.
A typical strange situation has 8 episodes as follows (taken from Shaffer, Wood, & Willoughby, 2002) :
- 1. Experimenter introduces parent and infant to the playroom and then leaves.
- 2. Parent sits while infant plays with toys. (Parent as a secure base)
- 3. Stranger enters, sits, and talks to parent. (Stranger anxiety)
- 4. Parent leaves, stranger offers comfort if the infant is upset. (Separation anxiety)
- 5. Parent returns, greets infant, and offers comfort if infant is upset. Stranger leaves. (Reunion behaviours)
- 6. Parent leaves room. (Separation anxiety)
- 7. Stranger enters and offers comfort. (Ability to be soothed by stranger)
- 8. Parent returns, greets infant, offers comfort if necessary, and tries to interest infant in toys. (Reunion behaviours)
* Note: All episodes except for the first episode last 3 minutes. However, if infants become extremely upset, separation episodes may be shortened and reunion episodes extended.
Ainsworth identified three patterns of attachment: secure, resistant and avoidant. Secure attachment, the ideal pattern of attachment, is found in approximately 7 in 10 infants (Myers & Spencer, 2001). It is characterized by the infants showing a distinct preference for their caregiver over the stranger. When the caregiver returns in the room, the infant will seek comfort and will be able to be calmed by the caregiver. The infant is usually outgoing with strangers while the mother is present. Caregivers of securely attached infants tend to respond promptly to their crying, reacting sensitively and appropriately.
Infants with resistant attachment show signs of tension in their relationship with their caregiver. They stay close to their caregiver before he or she leaves the room but exhibit both approach and avoidance behaviours when the caregiver returns. For instance, they may continue to show signs of distress, such as crying, when the caregiver returns in the room and may even push their caregiver away if the caregiver attempts to comfort them. These infants are usually quite wary of strangers, even when their mother is present. Resistant attachments are usually formed when caregivers are impatient with their infants and spend little time interacting with them (Carlson et al., 2002)
Infants with avoidant attachment usually do not show a distinct preference between their caregiver and the stranger. They tend to not to show distress when they are left alone and will most likely avoid or ignore their caregiver upon his or her return. These patterns of attachment are found in approximately 2 in 10 infants (Myers & Spencer, 2001). These infants are often quite sociable with strangers, however, they may sometimes ignore them in the same way that they ignore their caregiver. Avoidant attachment patterns are usually formed when caregivers are insensitive to their infant’s needs (Carlson et al., 2002).
As older children (i.e., over the age of 2) become less stressed by brief separations with their caregivers and encounters with strangers, the strange situation is not as useful for characterizing the attachments of older children. The Attachment Q-set (AQS) is an alternative assessment of attachment quality that can be used with children from age 1 to 5 years. It requires a parent or trained observer to sort a set of 90 descriptors of attachment-related behaviours (e.g., "Child greets mother with big smiles") into categories ranging from "most like" to "least like" the childs behaviours in order to gain a profile that reprsents how secure the child is. The Q-set has been found to be concordant with the strange situation attachment classification system (Pederson & Moran, 1996).
Mary Main & The AAI
Mary Main was one of Mary Ainsworth's students. In 1986 she identified a group of children more distrubed than the others and who did not fit Ainsworth's original 3 categories of attachment. She termed this fourth category of attachment"disoriented/disorganized" (Main & Soloman, 1990). Children who fit this attachment pattern demonstrated behaviours associated with both resistant and avoidant children in an unpredictable manner. This attachment pattern is said to characterize 5 to 10 percent of North American infants (Shaffer, Wood & Willoughby, 2002). Infants with this pattern of attachment appear to be the most troubled. They react to their caregiver in contradictory ways. For example, they might stop crying when held by their caregiver yet become rigid, turn their head away from their caregiver and show no emotion. Main reported that many of the mothers of disoriented children had been victims of trauma or had experienced losses in early childhood which were unresolved. She believed that the mothers anxiety and fearfulness were transmitted to the infant as a result. Disoriented attachments have also been reported to be found in the majority of abused infants (Carlson et al., 1989).
Main also contributed to the field of attachment by developing the Adult Attachment Interview (AAI) at the University of California at Berkley (Main & Goldwyn, 1993). The AAI is an interview that contains 20 questions which ask about one's experiences with parents and other attachment figures. The AAI also asks questions relating to significant losses in one's life, trauma, and experiences with their own children. It takes approximately 60 to 90 minutes to administer and is then scored by a trained person. The scoring process is complicated, requiring 2 weeks of intensive training followed by 18 months of reliability training for a research to be properly trained. When scoring the interview, the overall coherence of the subject's responses are analyzed.
Main's original purpose in developing the AAI was to translate Ainsworth's infant-mother attachment patterns into corresponding adult patterns. The AAI classifies an adult into one of the following three categories of attachment:
- Autonomous-secure (adult provided a clear and coherent account of early attachments, whether or not these attachments were satisfying or not)
- Preoccupied (adult spoke of conflicted childhood memories about attachment but did not draw them together into an organized, consistent picture)
- Dismissing (adult had an inability to recollect much about attachment relationships in childhood. When specific memories were recalled, they suggested episodes of rejection)
Father-Child Relationships and Attachment 
Although there has been a tendency in the past to focus on the mother-child relationship when discussing the concept of attachment, the role of fathers and the impact that they can have on children's attachment styles is becoming an increasingly popular area of interest. As traditional gender roles have changed over the last 30 years, more mothers are obtaining employment outside of the home and more fathers are taking on an active parenting role within the home (Dacey & Travers, 1996). This has called into question whether or not infants actually do react differently to each of their parents. Do the types of relationships and attachment styles that develop between parent and child differ for mothers and fathers?
Research exploring the similarity of mother and child attachment and father and child attachment reveals that there is no clear answer to this question, as several studies have come up with opposing results. When exploring the styles of attachment that develop between fathers and their children, Bowlby (1988) noted that the styles that emerge are very similar to the styles of attachment that form between mothers and their children. However, Bowlby also noted that, within the same family, there is no correlation "between the attachment patterns for each parent" (Dacey & Travers, 1996, 147). That is, mother and infant may be securely attached while father and infant may not or vice versa. Research shows that infants are more socially responsive when they are securely attached to both the mother and the father. Furthermore, there is evidence to suggest that a secure attachment with the father may buffer the potentially negative effects of an insecure mother-infant attachment (Shaffer, Wood & Willoughby, 2002).
Cultural Variations and Attachment 
The development of attachment is strongly influenced by cultural variables in that infant and parent attachment behaviours vary from culture to culture. For example, a study examining cross-cultural attachment patterns (Harwood, Miller, & Irizarry, 1995) found that Caucasian American mothers emphasize independence, self-reliance and self-confidence in their children as they believed that children should grow up to be self-sustaining individuals. In contrast, Puerto Rican mothers were found to emphasize respect, courtesy and tact when interacting with their children as they believed children should grow up to be polite and law-abiding citizens. Research also shows that resistant attachments, characterized by intense separation and stranger anxieties, are much more common in cultures where caregivers rarely leave their infants in substitute care, such as Japan (Shaffer, Wood, & Willoughby, 2002).
Some researchers argue that what qualifies as a secure or insecure attachment varies across cultures. For example, a secure attachment in Western societies is characterized by an infant being encouraged to separate themselves from their caregiver in order to explore the environment, and therefore becoming independent and autonomous. In contrast, Japanese mothers emphasize an infant's total dependence on the mother, causing Japanese babies to exhibit behaviours during separations and reunions that would classify them as insecurely attached when tested in the strange situation. Yet, these behaviours are exactly what would be considered highly adaptive in Japan because it emphasizes community and interdependence (Shaffer, Wood, & Willoughby, 2002).
Explanations of Attachment: How Does Attachment Develop? 
Depending on the theoretical stance that one takes to attachment, the mechanism through which the type of relationship that develops between parent and child may differ.
For example, psychoanalytic theorists, in line with Freud, would argue that infants become attached to those who fulfill their early desires, such as the desire for oral satisfaction. Infants become attached to their parents, and especially their mothers, because parents are primarily responsible for feeding the infant. Erikson, also a psychoanalyst, would argue that infants become attached because feeding allows for a sense of trust and security to develop between the mother and infant.
Behaviourists in line with Skinner, would emphasize the role of reinforcement in attachment. Different styles of attachment emerge based on how reinforcing the interaction between parent and infant is. Interactions that include close physcial contact, comforting, and appropriate stimulation (such as visual and vocal interaction) should be positively reinforcing and result in more secure types of attachment.
Although, cognitive-developmental theory does not offer much in terms of how infants form attachments with their caregivers, this theory does suggest that the ability to form attachments depends on the infant's level of cognitive development. Specifically, before an attachment can occur, an infant must be able to distinguish familiar individuals from strangers. Furthermore, an infant must also have "object permanence", as it would be difficult to become attached to a person who ceases to exist whenever they are out of view (Schaffer, 1971). It is interesting to note that attachments first emerge at around age 6 to 9 months, which is the same time when infants are entering Piaget's fourth sensorimotor substage when they are first able to search for and locate objects that they've seen someone hide from them (Shaffer, Wood & Willoughby, 2002).
An ethological theory of attachment stems from Konrad Lorenz's work (1937) on imprinting. He noted that very young ducklings followed almost any moving object, whether it be their mothers, another animal, or a human. He termed this behaviour "imprinting". He noted that imprinting is automatic in that young goslings do not have to be taught to follow, that it occurs within a critical period after the bird has hatched and is irreversible, in that once the young bird begins to follow a particular object/person, it remains attached to it (Shaffer, Wood & Willoughby, 2002). Lorenz concluded that imprinting was an adaptive response, increasing a young birds chances of survival if they follow their mothers to food. Arising from Lorenz's work, ethologists believe that many innate behaviours are designed to promote attachments between infants and their caregivers. The attachment relationship protects young from harm and ensures that their needs are met, permitting one to live long enough to reproduce in order for their species to survive.
Attachment and Later Development 
It is believed that the type of attachment an infant forms with his or her caregiver has implications for later life (Belsky & Cassidy, 1994), especially in how one forms relationships with others (Waters, Merrick, Treboux, Crowell & Albersheim, 2000). Securely attached infants are likely to display more favourable developmental outcomes. Securely attached adults find it easy to get close to others and don’t worry about becoming too dependent or being abandoned (Myers & Spencer, 2001). They also are more likely to report that their relationships are satisfying and enduring. Avoidant adults tend to be less invested in relationships and are more likely to leave them (Myers & Spencer, 2001). Avoidant adults have been found to be possessive, jealous and less trusting when in relationships. They often break up repeatedly with the same person (Myers & Spencer). Furthermore, among women, insecure attachments are correlated with clinical depression and difficulties in coping with stress (Barnas, Pollina, & Cummings, 1991).
Bowlby (1980, 1988) and Bretherton (1985, 1990) believe that infants use internal working models, or cognitive representations of themselves and other people, to interpret events and form expectations about relationships. Thus, sensitive, responsive caregiving leads to positive working models that view others as dependable. Insensitive, neglectful, or abusive caregivieng on the other hand, may lead to negative working models of others, characterized by insecurity and a lack of trust.
Attachment Application: Circle of Security Project 
The Circle of Security project (COS) is an example of how years of attachment theory and research is informing current interventions with at-risk caregivers and infants. The COS project was developed from contemporary attachment theory and is geared towards at-risk toddler, preschoolers and their caregivers (Marvin, Cooper, Hoffman, & Powell, 2002).
This COS project is a group based intervention. Six caregivers participate in 20 week (1.15 hours per week) sessions with a psychotherapist who leads the group. Theory and research informs an individualized program for each member in the group, based on the caregiver’s and their child’s attachment patterns. Attachment patterns are assessed prior to the intervention utilizing evidence based attachment procedures (e.g. Strange Situation, Adult Attachment Interview) (Marvin, Cooper, Hoffman, & Powell, 2002).
The intervention is focused on the caregiver, who is responsible for inducing change in the caregiver-child relationship. Caregivers are introduced to attachment theory in a user-friendly manner (e.g. pictorial graphs). Main constructs introduced examine Ainsworth’s ideas regarding the caregiver as a ‘secure base’ and a ‘haven of safety’ for their child. Parents are trained to identify and repair ‘disrupted’ interactions with their child. A pre and post intervention study reports successful outcomes; altering disorganized attachment patterns into secure attachment patterns. (Marvin, Cooper, Hoffman, & Powell, 2002).