Are Children with down Syndrome Less Careful in Performing a Tray-Carrying Task Than Children with other Types of Mental Retardation?

To investigate whether children with Down syndrome are less careful in performing motor tasks than children with other types of mental retardation, a tray-carrying task was devised in which subjects carried a tray bearing a glass filled with water which they tried not to spill. This task was given to children with Down syndrome (6 boys and 4 girls, n = 10) and those with other types of mental retardation (9 boys and 9 girls, n = 18; most of them diagnosed as undifferentiated). Mean chronological ages in the groups were 15.4 yr. for the Down group, and 16.3 yr. for the Mental retardation group. Mental ages were the same in both groups: 4.8 yr. The performance of children with Down syndrome was not significantly different from that of other children as measured by the amount of water spilled. Children with Down syndrome required more time and took more steps than the other children, although the time taken for each step was the same in both groups. The strategy of children with Down syndrome appeared to be to make each unit of movement smaller to carry out the given motor task.