to describe the distinctiveness of persons at every stage of
development. Many researchers have examined the relations of
temperament to emotions, behavior, and adjustment generally.
Fewer studies have focused primarily on the nature and structure
of temperament, however, and even fewer have examined
the developmental course of temperament. This Monograph
reports a significant exception. The authors undertook theoretically
relevant behavioral, biological, and self–report assessments
of a sample of 14–to–17 year olds who had been classified into
one of four temperamental groups at 4 months of age. Infant
temperamental categories were based on observed behavior
to a battery of unfamiliar stimuli. The infants classified as high
reactive (20 percent of the sample) displayed vigorous motor
activity and frequent crying. Those classified as low reactive (40
percent) displayed minimal motor activity and crying. About 25
percent of the infants, called distressed, showed minimal motor
activity but cried frequently, and 10 percent, characterized
by vigorous motoricity but little crying, were called aroused.
Previous evaluations of these children at 14 and 21 months,
and 4, 7, and 11 years had revealed that those children initially
classified as high reactive were most likely to be avoidant of
unfamiliar events at the early ages and emotionally subdued,
cautious, and wary of new situations at the later ages. By
contrast, initially low–reactive children had been the least
avoidant of unfamiliarity in the second year and most emotionally
spontaneous and sociable at the later ages. At age 11
years, assessments also had revealed that initially high–reactive
children were more likely than the low–reactive participants to
display right hemisphere activation in the EEG, a larger evoked
potential from the inferior colliculus, larger event related
waveforms to discrepant scenes, and greater sympathetic tone
in the cardiovascular system. In the follow–up of these individuals
reported here, adolescents (14 17 years of age) who had
been classified as high reactive in infancy were more likely than
initially low reactive participants to display sympathetic tone
in the cardiovascular system, to combine a fast latency with a
large magnitude of the evoked potential from the inferior colliculus,
and to show shallower habituation of the event–related
potential to discrepant visual events. Moreover, compared to
their low–reactive agemates, initially high reactive adolescents
more often reported being subdued in unfamiliar situations,
experiencing a dour mood and anxiety over the future, and being
religious. An important finding is that behavior and biology were
more clearly dissociated in adolescence than at earlier ages.
However, infant temperamental category at 4 months remained
a powerful predictor of behavior in adolescence, suggesting that
the features that characterize the two temperamental biases by
initially high– and low–reactive are not completely malleable to
the profound effects of brain growth and experience.
I. INTRODUCTION 1.
II. THE LONGITUDINAL STUDY 10.
III. THE CURRENT STUDY 19.
IV. RESULTS 31.
V. DISCUSSION 44.
COMMENTARY: Laurence Steinberg 76.
COMMENTARY: Nathan A. Fox 81.
STATEMENT OF EDITORIAL POLICY 94
Maryland College Park. His area of research interest is in social and
emotional development of infants and young children. He has developed
methods for assessing brain activity in infants and young children during
tasks designed to elicit a range of emotions. His work is funded by the
National Institutes of Health and includes a MERIT award. He currently
serves on the Biobehavioral Sciences standing review panel for NICHD.
Dr. Fox was awarded the Distinguished Scholar Teacher award from the
University of Maryland in 2005.
Laurence Steinberg (Ph.D., 1977, Cornell University) is the Distinguished
University Professor and Laura H. Carnell Professor of Psychology at
Temple University. His research focuses on biological and contextual
influences on normative and atypical development during adolescence,
most recently, on the connections between brain maturation and adolescent
Jerome Kagan (Ph.D., Yale University) is professor of psychology emeritus
at Harvard University, Cambridge, Massachusetts. He is the author of
Galen s Prophecy (1984), Three Seductive Ideas (2002), An Argument for Mind
(2006), and with Nancy Snidman of The Long Shadow of Temperament (2004).
His interests include infant temperament, cognitive development and
Nancy Snidman (Ph.D., University of California, Los Angeles) is the EEG
Research Director of TRANSCEND (Treatment, Research And Neuro–
SCience Evaluation of Neurodevelopmental Disorders) at Massachusetts
General Hospital. She is author with Jerome Kagan of The Long Shadow of
Temperament (2004). Her interests include biological correlates of temperament
and individual differences, autism and cognitive development.
Sara Towsley received her B.A. from Tufts University (2005) in clinical
psychology and her M.A. in psychology from Brandeis University (2007).
She is currently a research associate in the psychology department at
Vali Kahn received her B.A. from Bryn Mawr (1998) in psychology. She is
currently a graduate student in clinical psychology at University of
Massachusetts at Boston.