Home movies of eight normal children and eight children later diagnosed as autistic were analyzed based on: (1) Piagetian criteria of sensorimotor development and semiotic functioning, and (2) developmental levels of action competencies. The age range covered was 4 to 42 months of age. The analysis showed that, from the second year of life, timing…

Down Syndrome children (N=229), aged 1-83 months, from Australia, Canada, and Germany were tested using the Bayley Scales of Infant Development. Test performances on the Bayley's Mental and Motor scales were not dissimilar, leading to the conclusion that young Down Syndrome children from different countries with relatively comparable standards of…