The question of the stability and heritability of behavioral profiles and the question of continuities and discontinuities in development have been at the heart of scientific efforts in developmental psychology for over a century. While efforts to link newborn behavior and later development have been more successful in the case of extremely compromised infants or infants with severe biological disorders, little is known about the relationship between newborn behavior and later development in typical infants.

This study on the relationship between newborn behavior and temperament is a collaborative study being conducted by J. Kevin Nugent (P.I.), Cecilia F. Matson and Simona Bujoreanu from the Brazelton Institute and Jerome Kagan and Nancy Snidman from the Department of Psychology at Harvard University. The research of Dr. Kagan and his colleagues on temperament presents strong evidence to suggest that behavioral profile classifications of four-month-old infants are significantly related to behavioral profiles in the first, second, and third year of life and indeed up to twelve and fourteen years of age. The goal of this study is to examine the relationship between newborn behavioral patterns and temperament categories at 4 months.

In this study we are also testing out a revised, more objective version of the NBAS (NBAS-R) to measure the newborn behavioral patterns of 50 full-term, healthy babies between 24 and 72 hours of age. All our subjects were recruited at the Brigham and Women's Hospital in Boston soon after they were born. Currently, we are in the process of evaluating our subjects with the Four-Month Temperament Procedure developed by Dr. Kagan and his colleagues. This assessment is designed to observe how a 4-month baby reacts to new and different information that is presented to the senses through sight, sound, and smell. It measures the frequency and vigor of motor movements and the frequency and duration of crying. The temperament profile is reduced to four categories: 1. High motor and high cry, 2. High motor and low cry, 3. Low motor and high cry, and 4. Low motor and low cry. Dr. Kagan's previous research has shown that the high reactive infants (category 1) tend to become inhibited children later in life and that the low reactive infants (category 4) tend to be uninhibited.

The degree to which behavior in the newborn period may be related to later development is a question that has not only profound theoretical implications but also has important consequences for clinical practice and for the care of the newborn infant. This study should reveal whether the NBAS-R can identify temperament categories in the newborn period and whether these categories predict to temperament categories at later ages. In addition, this study will provide reliable information on the predictive validity of the revised form of the NBAS (NBAS-R).