Separation anxiety emerges according to a developmental timetable during the second half year in human infants. This development reflects advancing cognitive maturation, rather than the onset of problem behaviors.
As illustrated in the accompanying figure, infants from cultures as diverse as Kalahari bushmen, Israeli kibbutzim, and Guatemalan Indians display quite similar patterns in their response to maternal separation, which peaks at the end of the first year and gradually becomes less frequent and less intense throughout later infancy and the preschool years.
This fact has been interpreted to mean that the one-year-old is alerted by the absence of the parent and tries to understand that discrete event. If it fails, fear is created and the child cries.
Cultural practices have an impact on separation anxiety. Infants who remain in constant contact with their mothers may show an earlier onset of separation anxiety, and possibly more intense and longer periods of reactivity.
For example, Japanese infants who are tested in Mary Ainsworth’s Strange Situation show more intense reactions to the separation, presumably as a result of cultural norms prescribing constant contact between mother and infant for the first several years of life.
Like separation anxiety, researchers who observe infant emotions and behavior in the first month or two of life generally agree that no specific fear reaction is present at this early stage. Rather, infants become distressed due to unpleasant stimulation involving pain, discomfort, or hunger.
Typically researchers have found that by five to six months, if a stranger stares in silence at an infant, the infant will often return the look and after about 30 seconds begin to cry. Bronson has termed this distress reaction to a stranger’s sober face “wariness.”
Because of the gradual building up of tension in the infant, Bronson interprets the emotional distress as a reaction to the failure to assimilate the unfamiliar face to a more familar schema. In another words, the older infant can distinguish between familiar and unfamiliar faces, tries to understand the distinction, and becomes upset if the new face does not match the now familiar pattern.
A few months later, infants may react immediately to strangers, especially if approached suddenly or picked up by the stranger. This fear reaction, which can be readily elicited in most infants between seven and twelve months, has been called stranger distress or stranger anxiety.
The context and qualitative aspects of the stranger’s approach are critical in determining how an infant might respond. If the stranger approaches slowly when the caregiver is nearby, smiling and speaking softly, offering a toy, the infant will often show interest or joy, and distress is unlikely.
Also, the degree of distress shown by an infant to the silent intrusion of the stranger varies greatly from baby to baby, a finding that many believe to be rooted in the temperament of the infant.
Finally, if the infant finds the stranger’s approach to be ambiguous, the caregiver’s reaction will often influence the infant’s response. Should the parent smile and warmly greet the new person, the older infant will often use these emotional reactions as cues for how to respond.
Stranger distress was originally described by Rene Spitz as an emotion that suddenly appears in all infants at about 8 months. While we now understand how important a role context and cognition play in determining this response, there is nevertheless evidence suggesting a precise timetable for its emergence across different cultures, including Uganda, Hopi Indian, and the United States. A genetic basis has also been shown by twin research, with identical twins showing more similar onset of stranger distress than fraternal twins.
Rather than indicating emotional difficulties, the emergence of a fear of strangers in the second half of the first year is an indicator of cognitive development. For example, EEG and heart rate patterns in human infants both show a major developmental shift at this time in response to the presentation of threatening stimuli.
As infants acquire more experience in dealing with unfamiliar persons at family outings, visits to the home, or in day care, they no longer become distressed at the sight of a stranger. Young children show a wide variety of responses depending on the situation, their past experiences, and their level of sociability.
Parents will want to encourage their child’s natural curiosity and friendliness, while at the same time teaching them that they should always rely on parental guidance and approval in dealing with strangers.
The study of these two common fears of infancy underscores the important links between emotion and cognition. Discrepancy theories originating in the work of Hebb and Jean Piaget provide an account of the steps in the development of this basic emotional system in infancy and demonstrate its dependence on perceptual and cognitive development.
In addition, the importance of context and meaning have been clearly shown in the work of Jerome Kagan, Alan Sroufe, and others to be the hallmark of the mature fear response, as distinct from the general distress of early infancy.
While stranger distress and separation anxiety are normal for one-year-old infants, should a parent become concerned if they persist into the toddler or preschool years? The key to answering this question depends upon the nature of the child’s response, its intensity, and persistence over time.
For example, it is commonplace for young preschoolers to show some distress at separation from their parents during the first week or two of daycare in a new setting. Typically this settling in period does not last too long.
If a preschooler persists in showing excessive separation anxiety even after several weeks at a new preschool and this interferes with the child’s participation with peers and teachers, parents should consult with the teacher and other child care professionals. Childhood anxieties of this sort are generally quite responsive to treatment, and this may be a better option than waiting for the problem to resolve itself.