Today there is empirical evidence that the style of attachment an individual adopts during infancy, childhood, adolescence, and into adulthood is largely influenced by the biological mother (Zepf, 2011). Ainsworth described three styles of attachment that a child might have with an attachment figure: secure, anxious–avoidant, and anxious–ambivalent or resistant (Ainsworth, 1969). These styles of attachment were created based on an assessment technique known as the Strange Situation Classification (SSC), which consisted of the research portion of Ainsworth’s larger study that was used to assess separation and reunion behavior in children (McLeod, 2014). The SSC was a standardized research tool used to observe attachment styles exhibited by mothers and infants. The SSC revealed how infants relied on their mothers as a source of security by creating stresses designed to activate attachment behavior (Zepf, 2011). The assessment worked by having the mother and infant placed in an unfamiliar laboratory playroom, while a researcher behind a one-way mirror observed and recorded the child’s specific behaviors. The sample consisted of about 100 middle class American families, and the infants were between 12 and 18 months of age (McLeod, 2014).
Throughout the study, Ainsworth observed the behavior of the infant in a sequence of eight separate episodes, lasting about three minutes each (McLeod, 2014). In each episode, the infant was in a room either with the mother, the researcher, a stranger, or a combination thereof. The SSC followed a specific sequence of episodes with the mother, infant, and researcher: “(a) mother, infant, and researcher, (b) mother and baby alone, (c) stranger joins mother and infant, (d) mother leaves infant and stranger alone, (e) mother returns and stranger leaves, (f) mother leaves; infant left completely alone, (g) stranger returns, and (h) mother returns and stranger leaves” (McLeod, 2014, p. 970).
Ainsworth based the SSC on four interactional behaviors directed by the infant toward the mother in the two reunion episodes: (a) proximity and contact seeking, (b) contact maintaining, (c) avoidance of proximity and contact, and (d) resistance to contact and comforting (McLeod, 2014). Ainsworth recorded the behavior displayed during 15- second intervals and scored each infant’s behavior based on the level of intensity on a scale of 1 (low intensity) to 7 (high intensity) (McLeod, 2014). Other observed and recorded behaviors are (a) exploratory behaviors, consisting of the infant moving around the room, playing with toys, and looking around the room; (b) search behaviors, such as the infant following the mother to the door, the infant banging on the door, the infant looking at the door, the infant going to the mother’s empty chair, and the infant looking at the mother’s empty chair; and (c) affect displays, consisting of the infant crying or smiling (McLeod, 2014).
Ainsworth discovered that most of the one-year-old children played with the toys in the room, cried when their mother left the room, sought brief interaction and then settled down when the mother returned, and then resumed exploring the room (Ainsworth, 1969). However, not all the children followed the expected behavioral response. Upon the mother’s return after a brief absence, some of the children appeared to ignore the mother by looking away from her and refusing interaction with her even when she attempted interaction (Berghaus, 2011). Some of the children cried loudly when their mothers left the room, some appeared angry when she returned, even though they would often attempt to make contact with her. Based on these observed behaviors, Ainsworth identified three main attachment styles: securely attached, avoidant attached, and ambivalently attached (Ainsworth, 1969). Ainsworth suggested that mothers must respond to their child sensitively, notice and interpret infant cues, and respond consistently in a manner that does not misrepresent the infant’s needs (Ainsworth, 1969).
Ainsworth’s initial study to assess the attachment styles of infants and young children continues to be used today. For example, Cittern and Edalat (2014) developed an arousal-based neural model of infant attachment that can be used to deduce attachment styles in an SCC type of scenario. The arousal neural model has been used to expand on neuroscientific theories of attachment. The work of Ainsworth continues to inspire research and challenge behaviorism (Metcalf, 2010).
Further research by Ainsworth and Bowlby in the 1980s identified a fourth attachment style called disorganized attachment (Shivpuri, 2006). Disorganized attachment style reflects the absence of a coherent, coping strategy on the part of the child (Shivputi, 2006). This style of attachment behavior develops when the mother’s behavior is unpredictable, disorganized, and inconsistent, which causes fear and confusion for the child (Shivputi, 2006). According to Zepf (2011), unresolved trauma and loss in the life of the mother is usually the best predictor of disorganized attachment between mother and child. Mothers who have had traumatic experiences in their early life and have been unable to resolve those traumas are more likely to engage in disorganized and inconsistent parenting with their children (Zepf, 2011). Mothers who have a disorganized relationship with their children might react in a frightening way or might seem frightening to their children during moments of stress (Arditti, 2010). They might also act in ways that do not make sense to their children, demonstrating unpredictable, confusing, or erratic behavior. Because of negative early life experiences, these mothers might also see the world as an unsafe place (Zepf, 2011). According to Zepf (2011), the kind of attachment style developed by children is essentially a result of the quality of care received from the mother.
Each of the attachment styles can be associated with certain styles of behavior (Zepf, 2011). Infants are able to form attachments if there is someone to interact with, even if they are mistreated by that individual (R. Bowlby, 2008). Differences in the relationship between child and mother reflect the history of care provided: infants begin to predict the behavior of their mothers after recurrent interactions (Zepf, 2011). According to Bowlby (1960), sensitively responding to infant distress or the child’s need for protection and safety might be of the greatest importance in relation to children’s emotional and healthy developmental functioning.