Motor development during the first year: A comparative study

This investigation of the motor development characteristics of Brazilian in fants during the Ist year of postnatal life compared the findings with thos e of a widely used U.S. sample (N. Bayley, 1993). Analysis of the 12 monthl y assessments indicated that Brazilian infants' scores increased with age, with the greatest increase occurring over the first 8 months. As a general comparison, the results are similar to the U.S. patterns of development. Ho wever, the Brazilian sample exhibited mean scores significantly lower than the U.S. sample's in the 3rd, 4th, and 5th months. More specific analyses i ndicated that the difference within these months was on tasks of sitting an d grasping. Possible explanations for the differences focus on variations i n child-rearing practices and the influence of biological maturation in ear ly movement behaviors.