Temperament and the Reactions to Unfamiliarity, Jerome Kagan (1997)

Temperament and the Reactions to Unfamiliarity, Jerome Kagan (1997)
Review 9-21-10

In the article the author looks at aspects of behavior, or temperament, in infant’s response to caregivers though regularity, tempo, and emotional vigor. The article defines temperament as “the way an individual behaves”, and reports it is evident early in life. Temperament relates to behaviors across a wide range of situations and the article reports there is some evident that certain aspects of temperament might be inherited such as emotionality, activity and sociability. All vertebrates exhibit basic phenomena of having behavioral reactions to unfamiliar events. This has lead to interest by developmental psychologists. The author is attempting to study what has been learned about two temperamental types of children and their reactions to different ways of unfamiliarity.

462 healthy Caucasian, middle class, 16 week old infants were used in the study. “Highly reactive” infants in the study were defined by their reactions of becoming distressed when presentations of brightly colored toys were moved in front of their faces, cotton swabs dipped in dilute butyl alcohol applied to their nose and tape recordings of voices speaking brief sentences. 20% of the population was labeled as “highly reactive” and the 40% who remained relaxed were labeled as “low reactive”.

The infants were again introduced to stimuli at 14 to 21 months. One third of the 73 “high reactive” infants were highly fearful and only 3% showed minimal fear at both ages. One third of the 147 “low reactive” were minimally fearful at both ages and only 4% displayed high levels of fear, by contrast. High reactive children showed greater sympathetic reactivity in the cardiovascular system than the low reactive in the first 2 years.

The children gained control of their crying and reflex to retreat from unfamiliar events and only shoed these responses to dangerous events, which were not easily or ethical to create in a laboratory around 4 or 5 years. The children were interviewed at 4 and half years by an unfamiliar female examiner who was blind to their previous behavior. The “high reactive” children exhibited less significant smiles, 62 “high reactive” children talked and smiled significantly less often than the 94 “low reactive”, and male high reactive children had significantly higher resting heart rates then did the low reactive. Spontaneous comments and smiles were positively correlated. The article reports that high reactive children will be at a higher risk to develop anxiety disorders later in life during adulthood or adolescents. The article also discusses social class; “low reactive” children who are reared in homes where antisocial behavior is socialized may become candidates for delinquency.

The article also looks at the relation between psychological and biological constructs. Variation levels in hormones may accompanied by differences in the intensity and form of responsiveness to unfamiliarity. The difference in “high and low reactive” is interpreted as reflecting variation in the amygdala and its interactions with the hypothalamus, medulla, central gray, cingulated, and ventral striatum.

This article illustrates important points about development such as biological based tendencies with cognitive, emotional and social aspects of growth. The article reports that “4 month old infants who show a low threshold to become distressed are motorically aroused to unfamiliar stimuli are more likely than others to become fearful and subdued during early childhood, whereas infants who show a high arousal threshold are more likely to become bold and sociable.” As a reader, I am interested to see follow up studies on this. Would it be possible to study the children’s children from the study e.g. could we see if one could link high arousal children to having high arousal children? Another interesting idea for follow up research would be paired with neuroscience and the amygdala, due to research pointing towards it as storing fear memories. This article communicates to me that behaviors for survival can be stored and passed down for the survival of the species though evolution.