ABSTRACT
An infant's behavioral Drowsy state is his most continuous characteristic. He expresses his state by sleeping, wakefulness, or even by giving mixed signals of sleeping and wakefulness simultaneously. Sleep researchers have produced an enormous literature on neural, autonomic, and endocrine changes associated with sleep states. Researchers interested in organization of the infant's behavior and behavioral development have applied the same notion, that is, concordance of behaviors, to define states. A major premise for the studies described is that there is continuity as well as variability in the development of infant behaviors. An understanding of the factors that affect development requires measures for describing the initial characteristics of infants and then identifying changes in these characteristics as a consequence of encounters with the environment. Further study of infant behaviors may provide a basis for elaboration or consolidation of the behavior clusters for a system of classifying infant sleep and waking behaviors.
