The organization of exploratory behavior in Down syndrome and nondelayed infants.

The exploratory behaviors of a sample of 11 infants with Down syndrome and 11 nondelayed infants, matched on Bayley mental raw scores and gender, were analyzed. Transitional probabilities and z scores were computed for each possible behavior change as well as frequencies of each behavior. The analyses revealed significant differences in how the 2 samples distribute their exploratory activities. The significant transitional probabilities among the 6 behavioral states revealed a pattern of similarities and differences. In general, both groups of infants organized their exploratory activities in a similar manner. However, there were differences that appeared to depend on the level of exploratory sophistication. The results are discussed in the context of the similarities and differences between the samples.