Assessment of individual differences among healthy newborns on the Brazelton scale.

Inter-individual differences and behavioral stability assessed with the Brazelton scale were examined in twenty 3-8-day-old full-term newborns at a German newborn nursery. The extent of variability measurable with Brazelton scores was determined by the relative mean information value "Hrel" in each variable, which indicates the discriminating power of each scale. The value "Hrel" was high in irritability, consolability, cuddliness and alertness. Inter-individual differences, illustrated by individual mean scores, were lowest in orientating behaviors. Differences in alertness correlated with several other reaction patterns. No significant correlations were found between the NBAS variables and neonatal sex, birth weight, birth duration, and maternal age. However, the relative weight gain between day 1 and day 8 was correlated with alertness, orientation to face and to rattle, irritability, rapidity of build-up and state lability. Individual behavioral stability over time was generally low in most variables. The low degree of behavioral stability and the low relative mean information in several variables reduce the applicability of the scale for the originally suggested purposes.